Control channel transmission method and communication apparatus

Abstract

Embodiments of the present application relate to the technical field of communications, and provide a control channel transmission method and a communication apparatus, for use in reducing the receiving complexity of a terminal device when using two-stage downlink control information (DCI) to perform cell scheduling. The specific scheme comprises: receiving indication information, the indication information being used for indicating a first physical downlink control channel (PDCCH) candidate set; receiving first DCI; and monitoring second DCI on a second PDCCH candidate set, the second PDCCH candidate set being determined on the basis of the first DCI, and the second PDCCH candidate set belonging to the first PDCCH candidate set. The embodiments of the present application are used for the process of control channel transmission.

Description

Method and communication device for transmitting control channel

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on August 30, 2023, with application number 202311112834.7 and application name “A method and communication device for transmitting a control channel”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to the field of communication technologies, and in particular to a method and a communication device for transmitting a control channel. Background Art

[0003] In the new radio (NR), the physical downlink control channel (PDCCH) carries downlink control information (DCI) and can be used to schedule the physical downlink shared channel (PDSCH) or the physical uplink shared channel (PUSCH).

[0004] Currently, two-level DCI has been proposed, consisting of first-level DCI and second-level DCI. Two-level DCI carried by PDCCH can be used to send different downlink scheduling information, and together they can complete PDSCH / PUSCH scheduling or other functions, saving control channel resources and reducing PDCCH detection complexity on terminal devices. However, in a two-level DCI scenario, if two-level DCI is used to schedule at least one cell, the terminal device needs to detect the two-level DCI on multiple PDCCH candidates, which increases the reception complexity of the terminal device.

[0005] Summary of the Invention

[0006] The embodiments of the present application provide a method and a communication device for transmitting a control channel, which can reduce the reception complexity of a terminal device when applying two-level DCI for cell scheduling.

[0007] To achieve the above objectives, the present invention adopts the following technical solutions:

[0008] In a first aspect, a method for transmitting a control channel is provided, the method comprising: receiving indication information, the indication information being used to indicate a first physical downlink control channel candidate PDCCH candidate set; receiving first downlink control information DCI; and monitoring second DCI on a second PDCCH candidate set, the second PDCCH candidate set being determined based on the first DCI, and the second PDCCH candidate set belonging to the first PDCCH candidate set.

[0009] The first DCI and the second DCI can be understood as two-level DCI. The first DCI can also be referred to as the first-level DCI, and the second DCI can also be referred to as the second-level DCI. The first PDCCH candidate set can be understood as a search space set (search space set) configured by the network side for the terminal device to monitor the second DCI, and the PDCCH candidates within the time-frequency range of a control resource set (CORESET) associated with this search space set, including PDCCH candidates of different aggregation levels (AL).

[0010] Compared to the prior art in which, upon receiving the first PDCCH candidate set configured by the network side, the terminal device needs to monitor all PDCCH candidates in the first PDCCH candidate set, which results in a higher reception complexity for the terminal device, in the present application, upon receiving the first DCI, the terminal device can determine the second PDCCH candidate set from the first PDCCH candidate set based on the first DCI. The terminal device does not need to monitor the PDCCH candidates that belong to the first PDCCH candidate set but do not belong to the second PDCCH candidate set, and the reception complexity of the terminal device is lower. Moreover, the first DCI has been correctly received. If the second PDCCH candidate set for monitoring the second DCI is determined according to the first DCI, the reception performance of the terminal device for receiving the second DCI can be made equivalent to that of the first DCI.

[0011] In one possible design, monitoring the second DCI on the second PDCCH candidate set includes: in a case where the first DCI is detected within the first time interval, monitoring the second DCI on the second PDCCH candidate set within the first time interval. If the first DCI is detected in the first time interval, the terminal device may determine the second PDCCH candidate set on the first PDCCH candidate set corresponding to the first DCI detected in the first time interval, and monitor the second DCI on the second PDCCH candidate set. The first PDCCH candidate set corresponding to the first DCI detected in the first time interval is within the first time interval. The first DCI detected in the first time interval may correspond to one or more first PDCCH candidate sets. When the first DCI detected in the first time interval corresponds to multiple first PDCCH candidate sets, the terminal device needs to determine the second PDCCH candidate set for each first PDCCH candidate set in the multiple first PDCCH candidate sets, and after receiving the first DCI, monitor the second DCI on each first PDCCH candidate set in the multiple second PDCCH candidate sets, which can reduce the reception complexity of the second DCI received by the terminal device.

[0012] In one possible design, monitoring the second DCI on the second PDCCH candidate set includes: monitoring the second DCI on the second PDCCH candidate set in the second time interval when the first DCI is detected in the first time interval. If the first DCI is detected in the first time interval, the terminal device may determine the second PDCCH candidate set on the first PDCCH candidate set corresponding to the first DCI detected in the first time interval, and monitor the second DCI on the second PDCCH candidate set. The first PDCCH candidate set corresponding to the first DCI detected in the first time interval is within the second time interval. The first DCI detected in the first time interval may correspond to one or more first PDCCH candidate sets. The first time interval and the second time interval have different start times and the same time length. The start time of the second time interval is later than the start time of the first time interval. When the first DCI detected in the first time interval corresponds to multiple first PDCCH candidate sets, the terminal device needs to determine the second PDCCH candidate set on each first PDCCH candidate set in the multiple first PDCCH candidate sets, and after receiving the first DCI, monitor the second DCI on each first PDCCH candidate set in the multiple second PDCCH candidate sets, thereby reducing the reception complexity of the second DCI received by the terminal device.

[0013] In a second aspect, a control channel transmission method is provided, the method comprising: sending indication information, the indication information being used to indicate a first PDCCH candidate set; sending a first DCI, the first DCI being used to indicate a second PDCCH candidate set, the second PDCCH candidate set belonging to the first PDCCH candidate set; and sending a second DCI on the second PDCCH candidate set.

[0014] The first aspect describes that the terminal device side determines the second PDCCH candidate set based on the first PDCCH candidate set before receiving the second DCI. On the network side, for the wireless access network device, for example, for the base station, the base station can also determine the second PDCCH candidate set from the first PDCCH candidate set according to a similar process to the first aspect, and send the second DCI on the second PDCCH candidate set. In some embodiments, the process of the base station determining the second PDCCH candidate set is different from the process of the terminal device determining the PDCCH candidate set. For the base station, when the AL and the number of bits (size) of the first DCI and the AL and the size of the second DCI meet the relationship, the base station can send the second DCI on the PDCCH candidate corresponding to the determined AL of the second DCI. For the base station side, the complexity of the base station sending the second DCI is also reduced.

[0015] The following are various possible designs in the first and second aspects.

[0016] In one possible design, the first DCI and the second DCI are used to schedule data transmission in at least one cell. For example, the first DCI and the second DCI are used for multi-cell scheduling. In this way, the present application can reduce the reception complexity of the second DCI received by the terminal device when two-stage DCI is used for multi-cell scheduling.

[0017] In one possible design, the first DCI includes an indication of the number of bits of the second DCI. Exemplarily, the number of bits of the second DCI may be implicitly or explicitly indicated in the first DCI. Thus, when determining the second PDCCH candidate set from the first PDCCH candidate set, it may be determined based on the number of bits of the first DCI, the number of bits of the second DCI, and the AL received for the first DCI. Thus, when determining the AL range of the second DCI, the code rates of the second DCI and the first DCI are comparable, and the reception performance is comparable.

[0018] In one possible design, the second PDCCH candidate set is determined based on the AL of the PDCCH candidate carrying the first DCI. For example, the second PDCCH candidate set is determined based on the number of bits of the first DCI, the AL of the PDCCH candidate carrying the first DCI, and the number of bits of the second DCI. For example, the second PDCCH candidate set is determined based on the AL of the PDCCH candidate carrying the first DCI and the number of carriers scheduled by the second DCI. In the case where the second PDCCH candidate set is determined based on the AL of the PDCCH candidate carrying the first DCI, the reception complexity of the second DCI received by the terminal device can be reduced, and there is no need to monitor all PDCCH candidates in the first PDCCH candidate set.

[0019] In one possible design, the PDCCH candidates in the second PDCCH candidate set are PDCCH candidates in the first PDCCH candidate set whose AL is greater than or equal to the first AL; wherein the first AL is determined according to the number of bits of the first DCI, the AL of the PDCCH candidate carrying the first DCI, and the number of bits of the second DCI; or, the first AL is determined according to the AL of the PDCCH candidate carrying the first DCI and the number of carriers scheduled by the second DCI. In this way, when the first AL is determined according to the number of bits of the first DCI, the AL of the PDCCH candidate carrying the first DCI, and the number of bits of the second DCI, or when the first AL is determined according to the AL of the PDCCH candidate carrying the first DCI and the number of carriers scheduled by the second DCI, and the second PDCCH candidate set is obtained by screening PDCCH candidates in the first PDCCH candidate set that are greater than or equal to the first AL, the code rates of the second DCI and the first DCI can be made equivalent, and the reception performance can be made equivalent.

[0020] In one possible design, the number of PDCCH candidates in the second PDCCH candidate set is less than or equal to the preset total number. That is, when it is stipulated that the number of PDCCH candidates in the second PDCCH candidate set is less than the preset total number, and the AL in the first PDCCH candidate set is greater than or equal to the first AL, the terminal device can monitor the second PDCCH candidate set, that is, multiple PDCCH candidates, to ensure scheduling flexibility on the network side and avoid PDCCH blocking when two-level DCI performs multi-user scheduling.

[0021] In one possible design, the PDCCH candidates in the second PDCCH candidate set are the first preset total number of PDCCH candidates sorted from smallest to largest according to AL for the PDCCH candidates in the first PDCCH candidate set whose AL is greater than or equal to the first AL. In this way, while ensuring that the reception performance of the second DCI is comparable to that of the first DCI, a PDCCH candidate with a smaller AL can be used among the PDCCH candidates that meet the performance requirements to monitor the second DCI. When the AL is smaller, the number of occupied control channel elements (CCEs) is smaller, thereby saving PDCCH resource overhead.

[0022] In one possible design, the blind detection count of the PDCCH candidates of the first PDCCH candidate set is determined based on a preset total number. Compared to the prior art in which all PDCCH candidates of the first PDCCH candidate set are blindly detected, the present application can use the number of PDCCH candidates in the second PDCCH candidate set as the blind detection count of the first PDCCH candidate set after determining the second PDCCH candidate set, thereby reducing the complexity of performing blind detection of PDCCH candidates on the terminal device side.

[0023] In one possible design, the PDCCH candidates in the second PDCCH candidate set are the PDCCH candidates corresponding to the first preset number of ALs after sorting the ALs from small to large for the ALs whose ALs are greater than or equal to the first AL in the first PDCCH candidate set; the number of PDCCH candidates corresponding to any AL in the second PDCCH candidate set does not exceed the preset number corresponding to this AL. Among them, when the number of PDCCH candidates corresponding to any AL does not exceed the preset number corresponding to this AL, the number of PDCCH candidates corresponding to different ALs may be the same or may be different. In this way, by screening out some PDCCH candidates with smaller ALs in the first PDCCH candidate set and limiting the number of PDCCH candidates in each AL, the complexity of the second DCI monitoring on the terminal device side can be reduced, the PDCCH resource overhead can be saved, and the flexibility of multi-cell scheduling on the network side can be guaranteed.

[0024] In one possible design, the PDCCH candidate blind detection count of the first PDCCH candidate set is determined according to a preset number of levels and a preset number corresponding to each AL in the second PDCCH candidate set. This can also save PDCCH resource overhead when the terminal device performs PDCCH candidate blind detection.

[0025] In one possible design, the number of ALs of the PDCCH candidates in the second PDCCH candidate set is less than or equal to a preset number of levels. This reduces the complexity of the second DCI monitoring performed by the terminal device by screening out the PDCCH candidates corresponding to some ALs in the first PDCCH candidate set, saves PDCCH resource overhead, and ensures flexibility in multi-cell scheduling on the network side.

[0026] In one possible design, the PDCCH candidates in the second PDCCH candidate set are PDCCH candidates corresponding to the first preset number of ALs after sorting the ALs from small to large for the ALs in the first PDCCH candidate set that are greater than or equal to the first AL. In this way, by screening out the PDCCH candidates corresponding to the smaller ALs in the first PDCCH candidate set, the complexity of the second DCI monitoring on the terminal device side can be reduced, the PDCCH resource overhead can be saved, and the flexibility of multi-cell scheduling on the network side can be ensured.

[0027] In one possible design, the blind detection count of PDCCH candidates in the first PDCCH candidate set is determined based on a preset number of levels. That is, the blind detection count of PDCCH candidates in the first PDCCH candidate set by the UE may be the sum of the numbers of PDCCH candidates in the first PDCCH candidate set with an AL greater than or equal to the first AL, sorted from smallest to largest by AL, for the first preset number of ALs. This can also save PDCCH resource overhead when the terminal device performs blind detection of PDCCH candidates.

[0028] In one possible design, the count of non-overlapping CCEs of the PDCCH candidates of the first PDCCH candidate set is determined according to the maximum number of CCEs among the numbers of CCEs corresponding to the multiple PDCCH candidate subsets obtained by traversing the multiple possible monitoring results carrying the first DCI; wherein the multiple PDCCH candidate subsets all belong to the first PDCCH candidate set, and one of the multiple PDCCH candidate subsets is the second PDCCH candidate set. In this way, when the terminal device monitors the second DCI, the corresponding CCE count does not change with the change of the monitoring result of the first-level DCI, thereby reducing the implementation complexity of the terminal device and also reducing the PDCCH monitoring capability, that is, the overhead of the CCE capability.

[0029] In one possible design, the multiple monitoring results carrying the first DCI are multiple optional ALs of the PDCCH candidate carrying the first DCI; the CCE numbers corresponding to the multiple PDCCH candidate subsets obtained by traversing the multiple monitoring results of the first DCI include: according to the multiple optional ALs of the PDCCH candidate carrying the first DCI, the number of bits of the first DCI and the multiple possible numbers of bits of the second DCI, the CCE numbers corresponding to the PDCCH candidate subsets corresponding to each optional AL and each possible number of bits of the second DCI are obtained. In this way, according to the above method of determining the second PDCCH candidate set, multiple PDCCH candidate subsets are determined, and when the maximum CCE count among the multiple PDCCH candidate subsets is taken as the CCE count of the first PDCCH candidate set, the CCE count of the first PDCCH candidate set can be kept unchanged, thereby reducing the implementation complexity of the UE.

[0030] In one possible design, the minimum time interval between the second DCI and the data channel scheduled by the second DCI is determined based on the time interval between the first DCI and the second DCI. Because the parsing of the second DCI cannot begin until the parsing of the first DCI is completed, when the time interval between the second DCI and the first DCI is too close, the first DCI may not have been fully parsed. At this time, the second DCI needs to be parsed with a delay, which ultimately leads to a scheduling delay. The present application allows the minimum time interval between the second DCI and the data channel to flexibly change with the time interval between the first DCI and the second DCI, so that the parsing of the second DCI and the transmission configuration of the data channel can be completed within the minimum time interval between the second DCI and the data channel, thereby improving the transmission success rate of the data channel.

[0031] In one possible design, the first minimum time interval is the minimum time interval between the second DCI and the data channel when the time interval between the first DCI and the second DCI is greater than or equal to a threshold; the second minimum time interval is the minimum time interval between the second DCI and the data channel when the time interval between the first DCI and the second DCI is less than the threshold; the first minimum time interval is less than the second minimum time interval. That is, when the time interval between the first DCI and the second DCI is short, the minimum time interval between the second DCI and the data channel can be appropriately extended to improve the success rate of two-stage DCI parsing, thereby improving the success rate of data channel transmission.

[0032] According to a third aspect, a communication device is provided, which may be a terminal device, and includes: a receiving unit, configured to receive indication information, the indication information being used to indicate a first physical downlink control channel candidate PDCCH candidate set; the receiving unit, further configured to receive first downlink control information DCI; and the receiving unit, further configured to monitor a second DCI on a second PDCCH candidate set, the second PDCCH candidate set being determined based on the first DCI, and the second PDCCH candidate set belonging to the first PDCCH candidate set.

[0033] In a fourth aspect, a communication device is provided, which may be a network side device, such as a wireless access network device, and the communication device includes: a sending unit, used to send indication information, where the indication information is used to indicate a first PDCCH candidate set; the sending unit, further used to send a first DCI, where the first DCI is used to indicate a second PDCCH candidate set, where the second PDCCH candidate set belongs to the first PDCCH candidate set; and the sending unit, further used to send a second DCI on the second PDCCH candidate set.

[0034] In a fifth aspect, a communication device is provided. The communication device provided in this application has the function of implementing the network device behavior in one or more of any possible implementation methods of the first aspect, the second aspect, and the aspects above, and includes means for executing the steps or functions described in the above method aspects. The steps or functions can be implemented by software, hardware, or a combination of hardware and software.

[0035] In one possible design, the apparatus includes one or more processors and may further include a communication unit. The one or more processors are configured to support the apparatus in performing corresponding network device functions in the method described above. For example, determining a second PDCCH candidate set. The communication unit is configured to support the apparatus in communicating with other devices to implement receiving and / or transmitting functions. For example, transmitting the first DCI or the second DCI.

[0036] Optionally, the communication device may further include one or more memories coupled to the processor to store program instructions and / or data necessary for the network device. The one or more memories may be integrated with the processor or may be separate from the processor. This application is not limited thereto.

[0037] The communication device may be a base station, a gNB, a transmission and receiving point (TP), a centralized unit (CU) / distributed unit (DU), or the like, and the communication unit may be a transceiver or a transceiver circuit. Optionally, the transceiver may also be an input / output circuit or an interface.

[0038] The communication device may also be a chip, and the communication unit may be an input / output circuit or an interface of the chip.

[0039] In another possible design, the above-mentioned communication device includes a processor coupled to a memory. The memory is used to store a computer program, and the processor is used to execute the computer program in the memory, so that the device performs the method performed by the network device in the second aspect or any possible implementation of the second aspect. Furthermore, the device may also include a transceiver that performs transmission and / or reception under the control of the processor.

[0040] In one possible design, the apparatus includes one or more processors and may further include a communication unit. The one or more processors are configured to support the apparatus in performing corresponding functions of the terminal device in the above method. For example, determining a second PDCCH candidate set. The communication unit is configured to support the apparatus in communicating with other devices to implement receiving and / or transmitting functions. For example, receiving the first DCI or the second DCI.

[0041] Optionally, the communication device may further include one or more memories coupled to the processor to store program instructions and / or data necessary for the device. The one or more memories may be integrated with the processor or may be separate from the processor. This application is not limited thereto.

[0042] The communication device may be a terminal device, UE, smart terminal, or wearable device, and the communication unit may be a transceiver or a transceiver circuit. Optionally, the transceiver may also be an input / output circuit or an interface.

[0043] The communication device may be a chip, and the communication unit may be an input / output circuit or an interface of the chip.

[0044] In another possible design, the above-mentioned device includes a processor coupled to a memory. The memory is used to store a computer program, and the processor is used to run the computer program in the memory, so that the device performs the method performed by the terminal device in the first aspect and any possible implementation of the first aspect.

[0045] In a sixth aspect, a communication system is provided, which may include a network device (wireless access device) and at least one terminal device according to any possible implementation of any of the above aspects. The electronic device and the network device may perform the method for transmitting a control channel according to any of the above aspects and any possible implementation.

[0046] In the seventh aspect, an embodiment of the present application provides a computer-readable storage medium, including computer instructions. When the computer instructions are executed on an electronic device, the electronic device executes the method for transmitting a control channel in any of the above aspects and any possible implementation methods.

[0047] In an eighth aspect, an embodiment of the present application provides a computer program product. When the computer program product runs on a computer or a processor, it enables the computer or the processor to execute the method for transmitting a control channel in any of the above aspects and any possible implementation methods.

[0048] It can be understood that any of the terminal devices, network devices, communication devices, computer-readable storage media or computer program products provided above can be applied to the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding methods and will not be repeated here.

[0049] These and other aspects of the present application will become more readily apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] FIG1 is a schematic diagram illustrating one control resource set associated with two search space sets provided by an embodiment of the present application;

[0051] FIG2 is a schematic diagram of various over-configuration scenarios provided in an embodiment of the present application;

[0052] FIG3 is a schematic diagram of the time from the end of the last symbol of the PDCCH scheduling PUSCH to the start of the first uplink symbol of the corresponding PUSCH provided by an embodiment of the present application;

[0053] FIG4 is a schematic diagram of the architecture of a communication system provided in an embodiment of the present application;

[0054] FIG5 is a schematic flow chart of a method for transmitting a control channel according to an embodiment of the present application;

[0055] FIG6 is a schematic diagram of a search space set provided in an embodiment of the present application;

[0056] FIG7 is a schematic diagram of a PDCCH candidate in a second PDCCH candidate set provided by an embodiment of the present application;

[0057] FIG8 is a schematic diagram of a second PDCCH candidate set determined when a preset total number is 1 / 2 / 3 and the ALs carrying the first DCI are AL1 or AL2, provided by an embodiment of the present application;

[0058] FIG9 is a schematic diagram of a time domain relationship between a first DCI and a first PDCCH candidate set provided in an embodiment of the present application;

[0059] FIG10 is a schematic diagram of various possible methods for determining the count of non-overlapping CCEs of PDCCH candidates in the first PDCCH candidate set according to an embodiment of the present application;

[0060] FIG11 is a flow chart of a method for a base station to schedule a PUSCH through two-stage DCI according to an embodiment of the present application;

[0061] FIG12 is a schematic diagram of the minimum time interval when a base station schedules a PUSCH through two-stage DCI according to an embodiment of the present application;

[0062] FIG13 is a schematic structural diagram of a terminal device provided in an embodiment of the present application;

[0063] FIG14 is a schematic diagram of the structure of a network device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0064] For ease of understanding, some examples of concepts related to the embodiments of this application are provided for reference as follows:

[0065] 1. Subcarrier spacing (SCS).

[0066] In the new radio (NR), multiple SCSs are defined. The SCS number μ corresponds to 2 μ 15kHz. For example, the SCSs with sequence numbers μ 0 to 4 correspond to 15kHz, 30kHz, 60kHz, 120kHz, and 240kHz, respectively. In NR, a resource block (RB) is defined as 12 consecutive subcarriers in the frequency domain.

[0067] 2. Carrier and cell.

[0068] A carrier is a radio signal (electromagnetic wave) with a specific frequency, bandwidth, and format, emitted by the radio frequency equipment of a base station or terminal. It is the main body used to carry information in wireless mobile communications. The carrier used by the base station for transmission is called the downlink carrier, and the carrier used by the terminal for transmission is called the uplink carrier.

[0069] A cell is described by a higher layer (such as the radio resource control layer, media access control layer, and other protocol layers above the physical layer) from the perspective of resource management or mobility management. The coverage area of ​​each network device can be divided into one or more cells.

[0070] In the current NR standard, a cell can be configured with one downlink carrier. Optionally, a cell can also be configured with one uplink carrier or two uplink carriers. For a terminal device, the cell that provides service to it is called a serving cell. The cell involved in this application may also be a serving cell.

[0071] 3. Carrier aggregation and cross-carrier scheduling.

[0072] To achieve high-speed transmission, NR has a carrier aggregation (CA) mechanism. Terminals that support CA can transmit data on multiple carriers simultaneously, increasing the data transmission rate.

[0073] Each carrier in CA is also called a component carrier (CC).

[0074] The cell that can send the physical downlink control channel (PDCCH) corresponding to the data channel is called the scheduling cell, also known as the master cell; the cell that performs data channel transmission is called the scheduled cell. User equipment (UE) receives the PDCCH on the master cell and sends or receives data on the scheduled cell based on the control information carried in the PDCCH.

[0075] A cell's downlink carrier carries a control channel and schedules the cell's uplink and downlink data channels. This cell is a self-scheduling cell, acting as both a scheduling cell and a scheduled cell.

[0076] In CA, a cell's downlink carrier carries a control channel, which can schedule the uplink and downlink data channels of another cell. The cell carrying the control channel is called the scheduling cell, and the cell carrying the uplink and downlink data channels is called the scheduled cell. This type of scheduling is called cross-carrier scheduling (CCS). A single scheduling cell can correspond to multiple scheduled cells, meaning it can send control channels to schedule data for multiple scheduled cells.

[0077] 4. PDCCH.

[0078] A PDCCH candidate in a NR can contain L = {1, 2, 4, 8, 16} control channel elements (CCEs). Here, L is called the aggregation level (AL) of the PDCCH candidate. A CCE contains six resource-element groups (REGs), each of which corresponds to a resource block (RB) on an orthogonal frequency-division multiplexing (OFD) symbol.

[0079] A PDCCH candidate may or may not contain a PDCCH for a UE. A UE can monitor a PDCCH candidate to determine whether there is a PDCCH for it.

[0080] A search space with an aggregation level (AL) of L is defined as a set of PDCCH candidates with a size of L CCEs. A search space set is a set of search spaces with different ALs. The term "search space" is sometimes used broadly to refer to a search space, a search space set, multiple search space sets, or a class of search space sets.

[0081] A search space set is associated with a control resource set (CORESET). A control resource set is a concept introduced in NR. A control resource set is defined on a cell and contains a group of continuous or non-contiguous RBs in the frequency domain and 1 / 2 / 3 continuous OFDM symbols in the time domain.

[0082] 5. Search space set.

[0083] 1) Time domain parameters of the search space set.

[0084] A search space set can be associated with only one control resource set, and a control resource set can be associated with multiple search space sets.

[0085] A search space set is configured with time domain parameters such as period and offset. Based on the time domain parameters of the search space set and the time-frequency resource parameters of the associated CORESET, the size and location of the time-frequency resources corresponding to the search space set can be determined.

[0086] As shown in Figure 1, a schematic diagram of a control resource set associated with two search space sets (one control resource set is associated with search space set 1 and search space set 2). Based on the time-frequency resource parameters of the control resource set and the time domain parameters of the two associated search space sets, the time-frequency resource sizes and locations corresponding to the two search space sets can be determined.

[0087] 2) PDCCH candidate configuration of search space set.

[0088] The search space set configuration includes the AL and the number of PDCCH candidates corresponding to each AL. Based on these configurations and the time-frequency resource size and location corresponding to the search space set described above, the time-frequency resource location of the PDCCH candidates corresponding to this search space set can be determined using the rules specified by the protocol.

[0089] 3) Type of search space set.

[0090] There are two types of search space sets: common search space (CSS) and UE-specific search space (USS).

[0091] Type0-PDCCH CSS set, Type0A-PDCCH CSS set, Type1-PDCCH CSS set, and Type2-PDCCH CSS set are only configured on the primary cell. Type3-PDCCH CSS set and USS can be configured on the primary cell or secondary cell.

[0092] 6. PDCCH monitoring capability.

[0093] Two aspects of PDCCH monitoring significantly impact UE implementation complexity: the number of monitored PDCCH candidates, sometimes referred to as the number of blind detections (BDs), and the number of non-overlapping control channel elements (CCEs), sometimes referred to simply as the number of CCEs. The more PDCCH candidates monitored, the higher the UE's decoding complexity; and the greater the number of non-overlapping CCEs, the higher the UE's channel estimation complexity.

[0094] For each scheduled cell, the blind detection upper limit and non-overlapping CCE upper limit (BD / CCE upper limit) of the PDCCH candidates per unit time of the scheduling cell used to schedule the scheduled cell can be determined according to the protocol specifications. The unit time can be a number of consecutive OFDM symbols, specifically a time slot or a time span (SAPN).

[0095] For each tuned cell, the number of BDs and non-overlapping CCEs corresponding to the PDCCH candidates ultimately monitored by the UE shall not exceed the upper limit of the BD / CCEs for the tuned cell as determined according to the protocol. If a tuned cell is a secondary cell, the number of BDs and non-overlapping CCEs corresponding to the PDCCH candidates configured by the base station shall not exceed the upper limit of the BD / CCEs for the tuned cell as determined according to the protocol. If a tuned cell is a primary cell, the number of BDs and non-overlapping CCEs corresponding to the PDCCH candidates configured by the base station may exceed the upper limit of the BD / CCEs for the tuned cell as determined according to the protocol. The UE may partially delete these PDCCH candidates to ensure that the number of BDs and non-overlapping CCEs corresponding to the PDCCH candidates it ultimately monitors does not exceed the upper limit of the BD / CCEs for the tuned cell as determined according to the protocol. This overbooking for the primary cell will be described below.

[0096] 7. Over-configuration.

[0097] 1) Introduction of over-configuration.

[0098] As previously mentioned, the Type0-PDCCH CSS set, Type0A-PDCCH CSS set, Type1-PDCCH CSS set, and Type2-PDCCH CSS set are configured only on the primary cell. The PDCCH candidates in these CSSs may be used to send important messages such as broadcast information and are therefore quite important. Furthermore, due to the requirements of broadcast channels, the CSS may have a relatively long period.

[0099] Let's take an example to illustrate the reason for over-configuration. Assume that, according to the protocol, the upper limit of blind detection (BD) per slot in the primary cell is set to 44. Figure 2 illustrates various over-configuration scenarios. As shown in Figure 2 (a), a common search space (CSS) is configured in the primary cell, with a period of four slots. If an additional USS is configured for UE-spec scheduling in the primary cell, to ensure scheduling opportunities, it may be desirable for this USS to have PDCCH candidates in every slot. If this USS is configured with a period of one slot, as shown in Figure 2 (b), then to ensure that the BD per slot does not exceed the upper limit, the number of USS BDs will be relatively small. Another solution, as shown in Figure 2 (c), is to set the USS period to two slots, which may result in no USS in some slots. Alternatively, as shown in Figure 2 (d), two USSs (USS1 and USS2) are configured. This approach increases the number of USSs, but still presents the problem of a low number of PDCCH candidates in some slots.

[0100] To address this issue, the protocol stipulates that when configuring a next generation NodeB (gNB), the number of BDs / CCEs configured in certain slots / spans can exceed the upper limit. In this case, the UE is required to select some PDCCH candidates in that slot / span for monitoring according to the protocol to ensure that the number of monitored BDs / CCEs is less than or equal to the upper limit. As shown in Figure 2 (e), the UE makes a determination in each slot. If the number of BDs in the current slot exceeds the upper limit of 44, it can discard some USSs to ensure that the number of monitored BDs / CCEs is less than or equal to the upper limit of 44.

[0101] 2) Over-configuration processing.

[0102] First, the number of PDCCH candidates associated with the monitored CSS / the number of non-overlapping CCEs is subtracted from the upper limit of the number of PDCCH candidates monitored in one slot / span / the upper limit of the number of non-overlapping CCEs in one slot, respectively, to obtain two remaining totals.

[0103] For USSs, search spaces with smaller indices have higher priority. The number of PDCCH candidates / number of non-overlapping CCEs associated with each search space to be monitored is subtracted from the two remaining totals, in ascending order of index. If, for a given USS index, both remaining totals are greater than or equal to 0 after subtraction, the PDCCH candidate corresponding to that USS index can be monitored. If, for a given USS index, at least one of the two remaining totals is less than 0 after subtraction, the PDCCH candidate corresponding to that USS index and the PDCCH candidates corresponding to search spaces with a greater index do not need to be monitored.

[0104] After the overbooking process is completed, the number of PDCCH candidates / non-overlapping CCEs that the CSS on the primary cell and the USS scheduling the primary cell need to monitor does not exceed the BD / CCE upper limit.

[0105] 8. Downlink control information (DCI).

[0106] 1) Introduction to basic concepts of DCI.

[0107] In NR, DCI is carried on the PDCCH. For example, the DCI in the PDCCH that schedules the physical downlink shared channel (PDSCH) may contain control information such as the cell being scheduled, and the two resource indication fields of the PDSCH: frequency domain resource assignment and time domain resource assignment. The DCI in the PDCCH that schedules the physical uplink shared channel (PUSCH) may contain control information such as the cell being scheduled, and the two resource indication fields of the PUSCH: frequency domain resource assignment and time domain resource assignment.

[0108] 2) The size of the DCI.

[0109] There are two ways to understand the size of a DCI: the first is the number of bits in the DCI payload, and the second is the sum of the number of bits in the payload and the number of bits in the cyclic redundancy check (CRC). If the information bits in the DCI are padded, the number of bits in the payload is the sum of the number of information bits and the number of padding bits; if the information bits in the DCI are not padded, the number of bits in the payload is the number of information bits. In the NR system, for example, the bit width of the CRC is 24.

[0110] 3) Two-level DCI.

[0111] Two-level DCI consists of first-level DCI and second-level DCI. These two DCIs carry different downlink scheduling information and are used together to perform PDSCH / PUSCH scheduling or other functions. The number of information bits in first-level DCI is generally fixed, while the number of information bits in second-level DCI is generally variable. Two-level DCI can save control channel resources and reduce the complexity of PDCCH monitoring for UEs.

[0112] The use of two-level DCI in the multi-cell scheduling DCI format is currently under discussion. The multi-cell scheduling DCI format is introduced below.

[0113] 9. Multi-cell scheduling DCI format.

[0114] 1) The set of cells to be modulated.

[0115] Currently, two new DCI formats are being discussed in the standard. These two DCI formats can be used to schedule data transmission in two or more cells simultaneously, and are called multi-cell scheduling DCI formats. Table 1 shows an example of the two DCI formats.

[0116] Table 1

[0117] One UE may be configured with one or more scheduled cell sets, and the cells in each scheduled cell set may use the DCI format 0_3 / 1_3 shown in Table 1 for multi-cell scheduling.

[0118] For example, a UE is configured with two scheduled cell sets, where the first scheduled cell set includes cell 0, cell 1, cell 2, and cell 3, and the second scheduled cell set includes cell 4, cell 5, and cell 6. DCI format 0_3 can simultaneously schedule one or more cells among cell 0, cell 1, cell 2, and cell 3; and DCI format 1_3 can simultaneously schedule one or more cells among cell 4, cell 5, and cell 6.

[0119] A DCI format specified as a multi-cell scheduling DCI format can schedule data transmission on multiple cells, but not every DCI format specified as a multi-cell scheduling DCI format schedules data transmission on multiple cells simultaneously. A multi-cell scheduling DCI format contains an indication field that indicates one or more scheduled cells for the current DCI scheduling. These one or more scheduled cells are all cells in the scheduled cell set corresponding to the multi-cell scheduling DCI format.

[0120] Since multi-cell scheduling is scheduling multiple carriers in multiple cells, the multi-cell scheduling DCI format is sometimes also called a multi-carrier scheduling DCI format.

[0121] 10. Processing time of dynamically scheduled PUSCH.

[0122] NR defines two user capabilities (UE processing capability 1 and UE processing capability 2) for the PUSCH processing time (i.e., the time from the UE receiving the DCI scheduling PUSCH to the UE preparing to transmit the PUSCH).

[0123] Figure 3 shows the time from the end of the last symbol of the PDCCH that schedules the PUSCH to the start of the first uplink symbol of the corresponding PUSCH (including DMRS). The time from the end of the last symbol of the PDCCH that schedules the PUSCH to the start of the first uplink symbol of the corresponding PUSCH (including DMRS) is not less than T proc,2 =max((N2+d 2,1 )(2048+144)·κ2 -μ ·T C ,d 2,2 ). That is to say, when designing the terminal equipment, it must be able to proc,2 Only by being able to complete PDCCH reception and information analysis and generate the corresponding PUSCH within 10 seconds can the most stringent scheduling requirements be met.

[0124] 1) N2 is determined by the UE based on μ and its own processing capability, according to Table 2 (UE processing capability 1) and Table 3 (UE processing capability 2). Here μ corresponds to the downlink subcarrier spacing and uplink subcarrier spacing (μ DL ,μUL ) sequence number will produce the one with the larger Tproc,2.

[0125] 2)κ=T s / T c =64. In the NR system, Tc is a time unit, T c =1 / (Δf max ·N f ) where Δf max =480·10 3 Hz and N f =4096; κ represents the ratio between Ts and Tc, and takes a fixed value of κ = T s / T c =64. Among them, T s =1 / (Δf ref ·N f,ref ),Δf ref =15·10 3 Hz and N f,ref =2048.

[0126] 3) If the first symbol of the PUSCH contains only a demodulation reference signal (DMRS), d2,1=0; otherwise, d2,1=1.

[0127] 4)(N2+d 2,1 )(2048+144)·κ2 -μ ·T C This item corresponds to the PDCCH analysis time and PUSCH preparation time when bandwidth part (BWP) switching is not considered.

[0128] 5) If the scheduling DCI triggers the BWP switch, d 2,2 Equal to the BWP switching time, otherwise d 2,2 =0.

[0129] Table 2 PUSCH preparation time under UE processing capability 1

[0130] Table 3 PUSCH preparation time under UE processing capability 2

[0131] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings in the embodiments of the present application. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this article is merely a description of the association relationship of associated objects, indicating that three relationships can exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0132] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this embodiment, unless otherwise specified, "plurality" means two or more.

[0133] Typically, when two-level DCI is used to schedule at least one cell, the UE needs to perform PDCCH detection on multiple PDCCH candidates configured on the network side for detecting first-level DCI. Upon receiving the first-level DCI, the UE further performs PDCCH detection on multiple PDCCH candidates configured on the network side for detecting second-level DCI to determine whether the second-level DCI can be received. If the UE receives the second-level DCI, the UE parses the second-level DCI based on the parsing results of the first-level DCI to obtain the parsing results of the second-level DCI. Based on the parsing results of the first-level DCI and the second-level DCI, the UE prepares the PUSCH transmission configuration, coding, modulation, etc., and performs uplink transmission at the PUSCH transmission time. It can be seen that when detecting two-level DCI, the UE needs to detect each level of DCI on multiple PDCCH candidates, resulting in high UE reception complexity.

[0134] Therefore, an embodiment of the present application provides a method and a communication device for transmitting a control channel. In the method of the present application, if a terminal device receives a first-level DCI, the terminal device can determine, based on the first-level DCI, a set of PDCCH candidates for detecting the second-level DCI configured on the network side, that is, there is at least one PDCCH candidate in the set of PDCCH candidates for detecting the second-level DCI configured on the network side that does not belong to some of the PDCCH candidates. The terminal device does not detect the second-level DCI on the PDCCH candidate that does not belong to some of the PDCCH candidates, but only detects the second-level DCI on the PDCCH candidate that belongs to some of the PDCCH candidates.

[0135] This is equivalent to narrowing the range of PDCCH candidates for the terminal device to detect the second-level DCI, and the complexity of the terminal device detecting the second-level DCI is relatively low. Moreover, some PDCCH candidates for detecting the second-level DCI are determined based on the first-level DCI, and the first DCI has been correctly received by the terminal device. If the code rates of the first-level DCI and the second-level DCI are guaranteed to be equivalent, the determined part of the PDCCH candidates for detecting the second-level DCI can ensure the reception performance of the terminal device detecting the second-level DCI. In this way, while ensuring the reception performance of the second-level DCI and the flexibility of network-side scheduling, the complexity of the terminal device receiving the second-level DCI is reduced.

[0136] FIG4 is a schematic diagram of the architecture of a communication system used in an embodiment of the present application. As shown in FIG4 , the communication system 40 includes a wireless access network device 410 and at least one terminal device (such as terminal device 420 and terminal device 430 in FIG4 ). The terminal device is wirelessly connected to the wireless access network device, and the wireless access network device is wirelessly or wiredly connected to the core network device. The core network device and the wireless access network device can be independent and distinct physical devices, or the functions of the core network device and the logical functions of the wireless access network device can be integrated into the same physical device, or a single physical device can integrate some of the functions of the core network device and some of the functions of the wireless access network device. The terminal device can be fixed or mobile. FIG4 is merely a schematic diagram. The communication system 40 can also include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in FIG4 . The embodiments of the present application do not limit the number of wireless access network devices and terminal devices included in the communication system 40.

[0137] The wireless access network device 410 is an access device that the terminal device uses to access the communication system 40 wirelessly. It can be a base station NodeB, an evolved base station eNodeB, a base station in an NR mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi (wireless fidelity) system. The embodiments of this application do not limit the specific technology and specific device form adopted by the wireless access network device 410.

[0138] A terminal device may also be referred to as a terminal, UE, mobile station (MS), or mobile terminal (MT). A terminal device may be a mobile phone, tablet computer, computer with wireless transceiver capabilities, virtual reality (VR) terminal device, augmented reality (AR) terminal device, wireless terminal used in industrial control, wireless terminal used in self-driving vehicles, wireless terminal used in remote medical surgery, wireless terminal used in smart grids, wireless terminal used in transportation safety, wireless terminal used in smart cities, or wireless terminal used in smart homes.

[0139] The wireless access network equipment and terminal equipment can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can also be deployed on the water; and can also be deployed in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the wireless access network equipment and terminal equipment.

[0140] The embodiments of the present application can be applied to downlink signal transmission, uplink signal transmission, and device-to-device (D2D) signal transmission. For downlink signal transmission, the transmitting device is a wireless access network device, and the corresponding receiving device is a terminal device. For uplink signal transmission, the transmitting device is a terminal device, and the corresponding receiving device is a wireless access network device. For D2D signal transmission, the transmitting device is a terminal device, and the corresponding receiving device is also a terminal device. The transmission direction of the signals in the embodiments of the present application is not limited.

[0141] The wireless access network device 410 and the terminal device, as well as the terminal device and the terminal device, can communicate through a licensed spectrum (licensed spectrum), or can communicate through an unlicensed spectrum (unlicensed spectrum), or can communicate through both a licensed spectrum and an unlicensed spectrum at the same time. The wireless access network device and the terminal device, as well as the terminal device and the terminal device, can communicate through a spectrum below the sixth generation mobile communication technology (6G), or can communicate through a spectrum above 6G, or can use a spectrum below 6G and a spectrum above 6G at the same time. The embodiments of the present application do not limit the spectrum resources used between the wireless access network device 410 and the terminal device.

[0142] Applying the above communication system 40 and the solution overview provided above, the embodiments of the present application are introduced below.

[0143] FIG5 is a flow chart of a method for transmitting a control channel provided in an embodiment of the present application. The method includes the following process.

[0144] 501. A terminal device receives indication information, where the indication information is used to indicate a first PDCCH candidate set.

[0145] The embodiments of the present application are illustrated by taking the terminal device as UE and the wireless access network device as a base station as an example.

[0146] The terminal device receiving the indication information may include the terminal device receiving the indication information sent by the wireless access network device. Accordingly, the wireless access network device sending the indication information means that the wireless access network device sends the indication information to the terminal device.

[0147] Exemplarily, the base station may send a radio resource control (RRC) message to the UE, where the RRC message includes indication information. The indication information includes, for example, an identifier of at least one AL and the number of PDCCH candidates corresponding to each AL. When the UE receives the indication information, the UE may determine, based on the indication information, the ALs in the first PDCCH candidate set, the number of PDCCH candidates corresponding to each AL, and the time-frequency resources of each PDCCH candidate in the first PDCCH candidate set.

[0148] In some embodiments, the first-level DCI and the second-level DCI are used to schedule data transmission of at least one cell. The first PDCCH candidate set is a PDCCH candidate set configured by the radio access network device on the primary cell for monitoring the second-level DCI.

[0149] In some embodiments, the first PDCCH candidate set may be configured in the form of a search space set, i.e., a search space set, that is, the indication information is used to indicate the search space set. The first PDCCH candidate set is a PDCCH candidate set within the time-frequency resource range of the search space set of the first control resource set CORESET, that is, the search space set includes multiple first PDCCH candidate sets, wherein the first CORESET is the CORESET associated with the search space set.

[0150] Figure 6 is a schematic diagram of a first PDCCH candidate set. The above-mentioned search space set includes 2 AL2 PDCCH candidates, 2 AL4 PDCCH candidates and 1 AL8 PDCCH candidate in the time-frequency region of 1 control resource set. This is a first PDCCH candidate set. In this application, ALn represents the aggregation level n, and n is an integer greater than or equal to 2. In order to prevent obscuration, Figure 6 shows that one AL4 PDCCH candidate and one AL8 PDCCH candidate are outside the control resource set. It should be understood that, in fact, the AL4 PDCCH candidate and the AL8 PDCCH candidate are also in the control resource set.

[0151] 502. The terminal device receives the first DCI.

[0152] Accordingly, the radio access network device sends the first DCI.

[0153] In the embodiment of the present application, the first DCI may be understood as a first-level DCI, and the second DCI may be understood as a second-level DCI.

[0154] In some embodiments, the first DCI is used to indicate a second PDCCH candidate set, the second PDCCH candidate set belongs to the first PDCCH candidate set, and the second PDCCH candidate set is used for the terminal device to monitor the second DCI.

[0155] Exemplarily, the base station may send the first DCI on the PDCCH candidate set configured for the first DCI, and the UE may monitor the first DCI on the PDCCH candidate set configured for the first DCI. When the UE detects the first DCI, it may determine a second PDCCH candidate set from the first PDCCH candidate set based on the first DCI. The second PDCCH candidate set is different from the first PDCCH candidate set.

[0156] In some embodiments, the first DCI and the second DCI are used to schedule data transmission in a first cell. The first DCI and the second DCI are not identical. Data transmission in the first cell cannot be performed based solely on the first DCI; data transmission in the first cell cannot be performed based solely on the second DCI. The first DCI and the second DCI are also used to schedule data transmission in a second cell, which is different from the first cell. Data transmission can be replaced by signal transmission.

[0157] In some embodiments, the first DCI and the second DCI are not identical. Data transmission on the first carrier cannot be performed based solely on the first DCI; data transmission on the first carrier cannot be performed based solely on the second DCI. The first DCI and the second DCI are also used to schedule data transmission on a second carrier, which is different from the first carrier. The first carrier and the second carrier can be the uplink carrier and downlink carrier of the same cell, or the uplink carrier and downlink carrier of different cells.

[0158] 503. The terminal device monitors a second DCI on a second PDCCH candidate set, where the second PDCCH candidate set is determined according to the first DCI, and the second PDCCH candidate set belongs to the first PDCCH candidate set.

[0159] Accordingly, the radio access network device sends the second DCI on the second PDCCH candidate set. It should be noted that, before sending the second DCI, the radio access network device may also determine the second PDCCH candidate set based on the first PDCCH candidate set, and the implementation method may be similar to the method of determining the second PDCCH candidate set based on the first PDCCH candidate set on the terminal device side.

[0160] The terminal device does not monitor the second DCI on the PDCCH candidate included in the first PDCCH candidate set but not included in the second PDCCH candidate set. Accordingly, the radio access network device does not send the second DCI on the PDCCH candidate included in the first PDCCH candidate set but not included in the second PDCCH candidate set.

[0161] It should be noted that even if the radio access network device does not send the second DCI, the terminal device monitors the second DCI on the second PDCCH candidate set, but the monitoring result is that the second DCI is not detected.

[0162] In some embodiments, the second PDCCH candidate set is determined according to the AL of the PDCCH candidate carrying the first DCI.

[0163] This is equivalent to the terminal device determining the second PDCCH candidate set according to the AL of the PDCCH candidate carrying the first DCI, so that the terminal device monitors the second DCI on the second PDCCH candidate set.

[0164] In some embodiments, the second PDCCH candidate set is determined according to the number of bits of the first DCI, the AL of the PDCCH candidate carrying the first DCI, and the number of bits of the second DCI.

[0165] This is equivalent to the terminal device determining the second PDCCH candidate set according to the number of bits of the first DCI, the AL of the PDCCH candidate carrying the first DCI, and the number of bits of the second DCI, so that the terminal device monitors the second DCI on the second PDCCH candidate set.

[0166] The number of bits of the first DCI may be obtained by the terminal device from the network side before monitoring the first DCI, and the AL of the PDCCH candidate carrying the DCI is the AL of the PDCCH candidate detected by the terminal device for the first DCI. In some embodiments, the first DCI includes an indication of the number of bits of the second DCI, that is, includes the size of the second DCI.

[0167] Based on this, the terminal device monitors the second DCI on the second PDCCH candidate set including the following process.

[0168] 1) The terminal device determines the number of bits of the second DCI based on the first DCI.

[0169] Exemplarily, the first DCI may explicitly indicate or implicitly indicate the number of bits of the second DCI. Explicit indication means that the first DCI contains an indication field that directly indicates the number of bits of the second DCI. Implicit indication means that the first DCI contains one or more indication fields, and / or the PDCCH candidate that carries the detected first DCI contains information that can be used to determine the number of bits of the second downlink control information. For example, in a multi-cell scheduling DCI format, the first DCI includes a modulated carrier group indication field, and the UE determines the number of bits of the second DCI based on the modulated carrier group indication field in the first DCI. Possible situations include: when the modulated carrier group indication field in the first DCI indicates one modulated carrier, the number of bits of the second DCI determined by the UE is smaller; when the modulated carrier group indication field in the first DCI indicates four modulated carriers, the number of bits of the second DCI determined by the UE is larger. For example, the number of bits of the second DCI corresponding to one modulated carrier is 40, and the number of bits of the second DCI corresponding to four modulated carriers is 100.

[0170] 2) The terminal device determines a second PDCCH candidate set from the first PDCCH candidate set according to the number of bits of the first DCI, the AL of the PDCCH candidate carrying the first DCI, and the number of bits of the second DCI.

[0171] In some embodiments, the PDCCH candidates in the second PDCCH candidate set are PDCCH candidates in the first PDCCH candidate set whose AL is greater than or equal to the first AL.

[0172] The first AL is determined according to the number of bits of the first DCI, the AL of the PDCCH candidate carrying the first DCI, and the number of bits of the second DCI.

[0173] Exemplarily, the second PDCCH candidate set includes at least one first PDCCH candidate, and the AL of the first PDCCH candidate is greater than or equal to the first AL.

[0174] Wherein, when the base station is configured or preset by the protocol parameter a, the first AL can be determined by referring to the result of formula 1. The first AL is greater than or equal to The minimum AL. The value of a can be less than 1 or greater than or equal to 1. Alternatively, the network side or protocol can also not configure a, and the first AL can be determined by referring to the result of formula 2. The first AL is greater than or equal to The minimum AL. The result of Formula 1 or Formula 2 can be an integer or a decimal. If the result is a decimal, round it up to get the minimum AL. For example, according to the AL value range given above, when the result is 4, the first AL value is 4, expressed as AL4; when the result is 3, the first AL value is 4, expressed as AL4; when the result is 1.3, the first AL value is 2, expressed as AL2; and when the result is 4.9, the first AL value is 8, expressed as AL8.

[0175] When the minimum AL determined according to Formula 1 or Formula 2 is not within the AL value range, the first AL may be the maximum AL in the system. For example, in an NR system, the maximum AL is 16. When the determined minimum AL is not within the AL value range, the first AL is 16, represented as AL16.

[0176] Exemplarily, when the first AL is AL4, the PDCCH candidates in the second PDCCH candidate set are PDCCH candidates in the first PDCCH candidate set whose AL is greater than or equal to AL4.

[0177] The above-mentioned use of Formula 1 or Formula 2 to determine the AL range of the PDCCH candidate in the second PDCCH candidate set is mainly to ensure that the code rates of the first DCI and the second DCI are equivalent. Since the first DCI has been correctly received by the UE, if the PDCCH candidate in the second PDCCH candidate set that monitors the second DCI is a PDCCH candidate in the first PDCCH candidate set whose AL is greater than or equal to the first AL, the code rates of the second DCI and the first DCI can be made equivalent, thereby ensuring the reception performance of the second DCI. At the same time, the blind detection complexity of the UE monitoring the second DCI is also reduced. That is, the PDCCH candidates in the first PDCCH candidate set that are less than the first AL may not be monitored. In other words, the UE does not monitor the second DCI on the PDCCH candidate that does not belong to the second PDCCH candidate set but belongs to the first PDCCH candidate set. In other words, there is at least one PDCCH candidate in the first PDCCH candidate set that does not belong to the second PDCCH candidate set.

[0178] For example, assuming that the first PDCCH candidate set is the first PDCCH candidate set shown in FIG6 , FIG7 is a schematic diagram of the PDCCH candidates in the second PDCCH candidate set. For example, according to the prior art, the UE may need to monitor the five PDCCH candidates shown in FIG6 . According to the solution of the present application, when the second PDCCH candidate set includes one first PDCCH candidate, if the first DCI is carried on the PDCCH candidate of AL1, the first AL is AL2, and the UE may only need to monitor one PDCCH candidate of AL2; if the first DCI is carried on the PDCCH candidate of AL2, the first AL is AL4, and the UE may only need to monitor one PDCCH candidate of AL4. That is, the present application reduces the reception complexity of the second DCI by reducing the number of PDCCH candidates monitored by the UE for the second DCI.

[0179] In the above embodiment, the second PDCCH candidate set is determined based on the number of bits of the first DCI, the AL of the PDCCH candidate carrying the first DCI, and the number of bits of the second DCI. In other embodiments, the second PDCCH candidate set is determined based on the AL of the PDCCH candidate carrying the first DCI and the number of carriers scheduled by the second DCI.

[0180] This is equivalent to the terminal device determining the second PDCCH candidate set according to the AL of the PDCCH candidate carrying the first DCI and the number of carriers scheduled by the second DCI, so that the terminal device monitors the second DCI on the second PDCCH candidate set.

[0181] The AL of the PDCCH candidate carrying the DCI is the AL of the PDCCH candidate of the first DCI detected by the terminal device.

[0182] In some embodiments, the first DCI includes an indication of the number of carriers scheduled by the second DCI.

[0183] Based on this, the terminal device monitors the second DCI on the second PDCCH candidate set including the following process.

[0184] 1) The terminal device determines the number of carriers scheduled by the second DCI based on the first DCI.

[0185] For example, in a multi-cell scheduling DCI format, the first DCI includes a modulated carrier group indication field. The UE determines the number of carriers scheduled by the second DCI based on the modulated carrier group indication field in the first DCI. Possible scenarios include: the modulated carrier group indication field contains a bit map, where each bit corresponds to a carrier. When a bit value is 1, it indicates that the second DCI schedules the carrier corresponding to this bit. When a bit value is 0, it indicates that the second DCI does not schedule the carrier corresponding to this bit. The number of bits with a bit value of 1 is the number of carriers scheduled by the second DCI.

[0186] 2) The terminal device determines a second PDCCH candidate set from the first PDCCH candidate set according to the AL of the PDCCH candidate carrying the first DCI and the number of carriers scheduled by the second DCI.

[0187] In some embodiments, the PDCCH candidates in the second PDCCH candidate set are PDCCH candidates in the first PDCCH candidate set whose AL is greater than or equal to the first AL.

[0188] The first AL is determined according to the AL of the PDCCH candidate carrying the first DCI and the number of carriers scheduled by the second DCI.

[0189] Exemplarily, the second PDCCH candidate set includes at least one first PDCCH candidate, and the AL of the first PDCCH candidate is greater than or equal to the first AL.

[0190] Wherein, when the base station is configured or preset by the protocol parameter a, the first AL can be determined by referring to the result of formula 3. The first AL is greater than or equal to The minimum AL. The value of a can be less than 1 or greater than or equal to 1. Alternatively, the network side or protocol can also not configure a, and the first AL can be determined by referring to the result of formula 4. The first AL is greater than or equal to The minimum AL. The result of Formula 3 or Formula 4 may be an integer or a decimal. If the result is a decimal, it may be rounded up to obtain the minimum AL. For specific examples, see the examples of determining the first AL based on the results of Formula 1 / Formula 2 above.

[0191] In some embodiments, the second PDCCH candidate set includes other PDCCH candidates in addition to the first PDCCH candidate, and the ALs of all PDCCH candidates in the second PDCCH candidate set are greater than or equal to the first AL. In this way, when the second PDCCH candidate set includes multiple PDCCH candidates, the scheduling flexibility of the base station can be guaranteed, and PDCCH blocking can be avoided when scheduling multiple UEs.

[0192] In the case where the second PDCCH candidate set includes multiple PDCCH candidates, the way in which the UE determines the second PDCCH candidate set may refer to the following two schemes, but is not limited to the following two schemes. In scheme one, the number of PDCCH candidates in the second PDCCH candidate set is less than or equal to the preset total number. For example, the base station configuration or protocol presets the number of PDCCH candidates in the second PDCCH candidate set to be the preset total number. The preset total number is less than the number of PDCCH candidates in the first PDCCH candidate set. The UE needs to determine the preset total number of PDCCH candidates in the first PDCCH candidate set.

[0193] For solution 1, two possible implementations are given here.

[0194] Method 1: The PDCCH candidates in the second PDCCH candidate set are the first preset total number of PDCCH candidates sorted from small to large according to AL for the PDCCH candidates in the first PDCCH candidate set whose AL is greater than or equal to the first AL.

[0195] In this way, the second PDCCH candidate set determined in the first PDCCH candidate set can use PDCCH candidates with a smaller AL among the PDCCH candidates that meet the reception performance of the second DCI, thereby saving PDCCH resource overhead.

[0196] Exemplarily, Figure 8 shows a schematic diagram of the second PDCCH candidate set determined when the above-mentioned preset total number is 1 / 2 / 3 and the AL carrying the first DCI is AL1 or AL2 respectively. Still taking the first PDCCH candidate set as the first PDCCH candidate set shown in Figure 6 as an example, as shown in (a) of Figure 8, when the AL carrying the first DCI is AL1, if the first AL is AL2, the preset total number is 1, and the second PDCCH candidate set is one PDCCH candidate with AL AL2 in the first PDCCH candidate set. If there are multiple PDCCH candidates with AL AL2 in the first PDCCH candidate set, the UE can select any one or determine one PDCCH candidate with AL AL2 according to a certain rule. Similarly, when the AL carrying the first DCI is AL2, if the first AL is AL4, the preset total number is 1, and the second PDCCH candidate set is one PDCCH candidate with AL AL4 in the first PDCCH candidate set. If there are multiple PDCCH candidates with AL being AL4 in the first PDCCH candidate set, the UE may select any one or determine one PDCCH candidate with AL being AL4 according to a certain rule.

[0197] As shown in (b) of Figure 8 , when the AL carrying the first DCI is AL1, if the first AL is AL2, the preset total number is 2, and the second PDCCH candidate set consists of two PDCCH candidates in the first PDCCH candidate set whose AL is AL2. When the AL carrying the first DCI is AL2, if the first AL is AL4, the preset total number is 2, and the second PDCCH candidate set consists of two PDCCH candidates in the first PDCCH candidate set whose AL is AL4.

[0198] As shown in (c) of Figure 8 , when the AL carrying the first DCI is AL1, if the first AL is AL2, the preset total number is 3, and the second PDCCH candidate set is 2 PDCCH candidates with AL2 and 1 PDCCH candidate with AL4 in the first PDCCH candidate set. When the AL carrying the first DCI is AL2, if the first AL is AL4, the preset total number is 3, and the second PDCCH candidate set is 2 PDCCH candidates with AL4 and 1 PDCCH candidate with AL8 in the first PDCCH candidate set.

[0199] It should be noted that the number of PDCCH candidates with AL greater than or equal to the first AL in the first PDCCH candidate set may be less than the preset total number. In this case, the number of PDCCH candidates in the determined second PDCCH candidate set will be less than the preset total number.

[0200] In some embodiments, the blind detection count of the PDCCH candidates of the first PDCCH candidate set is determined according to a preset total number. The blind detection count of the PDCCH candidates of the first PDCCH candidate set for the second DCI is a preset total number. If the first PDCCH candidate may carry other DCI in addition to the second DCI, the blind detection count of the DCCH candidates of the first PDCCH candidate set is determined according to the blind detection count of the PDCCH candidates for other DCIs and the blind detection count of the PDCCH candidates for the second-level DCI. For example, the blind detection count of the DCCH candidates of the first PDCCH candidate set is the sum of the blind detection count of the PDCCH candidates for other DCIs and the blind detection count of the PDCCH candidates for the second-level DCI.

[0201] If the UE needs to perform over-allocation processing, the blind detection count of the first PDCCH candidate set determined according to the preset total number may be used.

[0202] Mode 2: The PDCCH candidates in the second PDCCH candidate set are PDCCH candidates corresponding to the first preset number of ALs after sorting the ALs in the first PDCCH candidate set from small to large according to ALs greater than or equal to the first AL.

[0203] The number of PDCCH candidates corresponding to any AL in the second PDCCH candidate set does not exceed the preset number corresponding to any AL.

[0204] The preset number of levels may be configured by the base station for the UE or preset by the protocol, and is not limited in this application. The preset number of levels is a positive integer greater than or equal to 1. The preset number may be configured by the base station for the UE or preset in the UE through the protocol, and is not limited in this application.

[0205] In this application, there are two ways to configure a parameter (such as the preset level number, preset number, or preset total number in the embodiments of this application) using high-level signaling by a base station: explicit configuration and implicit configuration. Explicit configuration by the base station directly configures the value of a parameter. Implicit configuration by the base station means that the protocol stipulates that the base station can explicitly configure the value of a parameter, but the base station does not configure this parameter in the signaling that can configure this parameter. In this case, the protocol stipulates that the base station can be considered to have configured a default value, such as 1.

[0206] Exemplarily, the preset number is a positive integer greater than or equal to 1 configured by the base station to the UE, or preset by the protocol, and the preset number corresponding to each AL in the second PDCCH candidate set is the same preset number, that is, the number of PDCCH candidates for each AL in the second PDCCH candidate set is less than or equal to this preset number.

[0207] For example, the AL carrying the first DCI is AL1, the first AL is AL2, the preset number of levels is 3, and the preset number is 1. Taking the first PDCCH candidate set as the first PDCCH candidate set shown in Figure 6 as an example, the UE can determine 1 PDCCH candidate with AL being AL2, 1 PDCCH candidate with AL being AL4, and 1 PDCCH candidate with AL being AL8 in the first PDCCH candidate set.

[0208] In some embodiments, the blind detection count of the PDCCH candidates of the first PDCCH candidate set is determined according to a preset number of levels and a preset number corresponding to each AL in the second PDCCH candidate set. The blind detection count of the PDCCH candidates of the first PDCCH candidate set for the second DCI is the preset number of levels × the preset number. If the first PDCCH candidate may carry other DCIs in addition to the second DCI, the blind detection count of the DCCH candidates of the first PDCCH candidate set is determined according to the blind detection count of the PDCCH candidates for other DCIs and the blind detection count of the PDCCH candidates for the second-level DCI. For example, the blind detection count of the DCCH candidates of the first PDCCH candidate set is the sum of the blind detection count of the PDCCH candidates for other DCIs and the blind detection count of the PDCCH candidates for the second-level DCI.

[0209] If the UE needs to perform over-allocation processing, the blind detection count of the first PDCCH candidate set determined according to the preset level number and the preset number may be used.

[0210] Exemplarily, the preset number is independently configured by the base station for each AL in the second PDCCH candidate set, or is independently preset by the protocol for each AL in the second PDCCH candidate set. The preset number corresponding to each AL is a positive integer greater than or equal to 1. The preset numbers corresponding to different ALs can be configured to be the same or different. The number of PDCCH candidates for each AL in the second PDCCH candidate set is less than or equal to the preset number corresponding to this AL.

[0211] For example, the AL carrying the first DCI is AL1, the first AL is AL2, the preset number of levels is 3, the preset number corresponding to AL2 is 1, the preset number corresponding to AL4 is 2, and the preset number corresponding to AL8 is 1. Taking the first PDCCH candidate set as the first PDCCH candidate set shown in Figure 6 as an example, the UE can determine 1 PDCCH candidate with AL2, 2 PDCCH candidates with AL4, and 1 PDCCH candidate with AL8 in the first PDCCH candidate set.

[0212] In some embodiments, the PDCCH candidate blind detection count of the first PDCCH candidate set is determined according to a preset number of levels and a preset number corresponding to each AL in the second PDCCH candidate set.

[0213] For example, the blind detection count of the PDCCH candidate for the second DCI of the first PDCCH candidate set is the sum of the preset numbers corresponding to each AL in the second PDCCH candidate set. If the first PDCCH candidate may carry other DCI in addition to the second DCI, the blind detection count of the DCCH candidate of the first PDCCH candidate set is determined according to the blind detection count of the PDCCH candidate for other DCI and the blind detection count of the PDCCH candidate for the second-level DCI, for example, the sum of the blind detection count of the PDCCH candidate for other DCI and the blind detection count of the PDCCH candidate for the second-level DCI. If the UE needs to perform over-matching processing, the blind detection count of the first PDCCH candidate determined according to the preset number of levels and the preset number corresponding to each AL in the second PDCCH candidate set can be used.

[0214] Solution 2: The number of ALs of the PDCCH candidates in the second PDCCH candidate set is less than or equal to the preset number of levels.

[0215] Among them, the preset number of levels can be configured by the base station or preset in the UE through a protocol. That is, when determining the second PDCCH candidate set, when the AL of the PDCCH candidates in the second PDCCH candidate set is greater than or equal to the first AL, the PDCCH candidates corresponding to the preset number of ALs in the first PDCCH candidate set are screened out. Exemplarily, assuming that the first AL is 2 and the preset number of levels is 2, the UE needs to determine 2 types of ALs in the first PDCCH candidate set, and both types of ALs are greater than or equal to AL2. For example, the 2 types of ALs are the 2 PDCCH candidates with AL2 and the 2 PDCCH candidates with AL4 in the first PDCCH candidate set shown in Figure 6.

[0216] In some embodiments, under solution 2, the PDCCH candidates in the second PDCCH candidate set are PDCCH candidates corresponding to the first preset number of ALs after sorting the ALs in the first PDCCH candidate set from small to large according to ALs greater than or equal to the first AL.

[0217] Exemplarily, when the preset level number is 1, the UE selects all PDCCH candidates whose AL is the first AL in the first PDCCH candidate set as PDCCH candidates in the second PDCCH candidate set. For example, if the first AL is 2, in the first PDCCH candidate set shown in FIG6 , the PDCCH candidates in the second PDCCH candidate set are the two PDCCH candidates whose AL is AL2 in the first PDCCH candidate set.

[0218] When the preset level number is 2, the UE selects all PDCCH candidates whose ALs are the first AL and the first AL×2 in the first PDCCH candidate set as PDCCH candidates in the second PDCCH candidate set. For example, if the first AL is 2, in the first PDCCH candidate set shown in FIG6 , the PDCCH candidates in the second PDCCH candidate set are the two PDCCH candidates whose ALs are AL2 and the two PDCCH candidates whose ALs are AL4 in the first PDCCH candidate set.

[0219] When the preset number of levels is 3, the UE selects all PDCCH candidates whose ALs are the first AL, the first AL×2, and the first AL×4 in the first PDCCH candidate set as PDCCH candidates in the second PDCCH candidate set. For example, if the first AL is 4, in the first PDCCH candidate set shown in FIG6 , the PDCCH candidates in the second PDCCH candidate set are two PDCCH candidates whose ALs are AL4 and one PDCCH candidate whose ALs are AL8 in the first PDCCH candidate set. Since there is no PDCCH candidate whose AL is AL16 in the first PDCCH candidate set, the second PDCCH candidate set does not include a PDCCH candidate whose AL is AL16.

[0220] That is to say, in the first PDCCH candidate set, when screening PDCCH candidates according to scheme 2, it may happen that some ALs do not exist. The example in which the preset level number is 3 is equivalent to discarding the PDCCH candidates of the AL that does not exist in the first PDCCH candidate set. This is one way of processing. For another example, when the preset level number is 2, when screening PDCCH candidates with AL of the first AL and the first AL×2 in the first PDCCH candidate set, if there is no PDCCH candidate with the first AL×2 in the first PDCCH candidate set, only all PDCCH candidates with AL of the first AL in the first PDCCH candidate set are screened as PDCCH candidates in the second PDCCH candidate. In another processing method, the PDCCH candidates with the first AL and the first AL×4 in the first PDCCH candidate set can also be taken as PDCCH candidates in the second PDCCH candidate. That is, skip the non-existent AL and take the minimum AL among the non-existent ALs to continue screening the PDCCH candidates.

[0221] In some embodiments, according to the method of determining the second PDCCH candidate set in accordance with the second solution, the PDCCH candidate blind detection count of the first PDCCH candidate can be determined according to a preset number of levels. For example, the sum of the number of PDCCH candidates corresponding to the preset number of ALs in the first PDCCH candidate set whose AL is greater than or equal to the first AL is used as the PDCCH candidate blind detection count of the first PDCCH candidate set for the second DCI. When performing over-matching processing, the blind detection count of the first PDCCH candidate set determined according to the preset number of levels can be used.

[0222] In the embodiment of the present application, the relationship between the first PDCCH candidate set and the second PDCCH candidate set is further explained here.

[0223] In some embodiments, monitoring the second DCI on the second PDCCH candidate set includes: when the first DCI is detected within a first time interval, monitoring the second DCI on the second PDCCH candidate set within the first time interval. This is because, within the first time interval, there is a time domain correspondence between the first DCI and the first PDCCH candidate set for monitoring the second DCI. Exemplarily, the first time interval can be one slot, or multiple slots, or one time span, or multiple spans.

[0224] For example, FIG9 shows a schematic diagram of the time domain relationship between a first DCI and a first PDCCH candidate set. Assuming that the base station is configured with a first USS, the first USS is associated with the first CORESET, and the first PDCCH candidate set is a PDCCH candidate set within the time-frequency resource range of the first USS of the first CORESET, that is, the USS contains multiple first PDCCH candidate sets. When the UE detects one first DCI, the first DCI may correspond to one or more first PDCCH candidate sets to be monitored. As shown in (a) of FIG9 , when the first time interval is one time slot, in one first time interval, one first DCI corresponds to one first PDCCH candidate set for monitoring the second DCI. In some scenarios, there may be more than two first PDCCH candidate sets in one first time interval, which is not limited in this application. As shown in (b) of FIG9 , when the first time interval is two time slots, in one first time interval, one first DCI corresponds to two first PDCCH candidate sets for monitoring the second DCI.

[0225] That is, the first PDCCH candidate set can be understood as all PDCCH candidates in one control resource set associated with the first USS. For example, the first PDCCH candidate set is the five PDCCH candidates shown in Figure 6. The UE needs to determine the second PDCCH candidate set based on the first DCI received in each first time interval for each first PDCCH candidate set in each first time interval. If the PDCCH candidate detected for the first DCI is different in different first time intervals, the second PDCCH candidate set determined from the first PDCCH candidate set in the first time interval may also be different.

[0226] The time domain correspondence between the first DCI and the first PDCCH candidate set is configured by high-layer signaling, or in other words, the time domain correspondence between the PDCCH candidate set monitoring the first DCI and the first PDCCH candidate set is configured by high-layer signaling.

[0227] The possible situations here are: 1) The UE monitors the first DCI on the first PDCCH candidate set. If the first DCI is detected, the UE determines the second PDCCH candidate set based on the number of bits of the first DCI, the number of bits of the second DCI and the AL of the PDCCH candidate carrying the first DCI, and monitors the second DCI on the second PDCCH candidate set. For example, in the example shown in (a) in Figure 9, the first time interval is 1 time slot, and the first DCI is detected in time slot 1 / time slot 4. When the first DCI is carried on the PDCCH candidate of AL1, the second PDCCH candidate set is determined in the first PDCCH candidate set corresponding to the first DCI, and the PDCCH candidates in the second PDCCH candidate set are 2 PDCCH candidates with AL of AL2. When the first DCI is not detected in time slot 2, the UE does not need to monitor the second DCI in the first PDCCH candidate set, and the second PDCCH candidate set is empty. When a first DCI is detected in time slot 3 and the first DCI is carried on a PDCCH candidate of AL2, a second PDCCH candidate set is determined in the first PDCCH candidate set corresponding to the first DCI. The PDCCH candidates in the second PDCCH candidate set are two PDCCH candidates with AL4.

[0228] For another example, in the example shown in (b) of Figure 9, when the first time interval is 2 time slots, when the first DCI is detected in the first time interval of time slot 1 and time slot 2, and the first DCI is carried on the PDCCH candidate of AL1, two second PDCCH candidate sets are determined from the two first PDCCH candidate sets corresponding to the first DCI, and the PDCCH candidates in each second PDCCH candidate set are two PDCCH candidates with AL being AL2. When the first DCI is detected in the first time interval of time slot 3 and time slot 4, and the first DCI is carried on the PDCCH candidate of AL2, two second PDCCH candidate sets are determined from the two first PDCCH candidate sets corresponding to the first DCI, and the PDCCH candidates in each second PDCCH candidate set are two PDCCH candidates with AL being AL4.

[0229] 2) The base station configures another USS, namely the second USS (the PDCCH candidate set for monitoring the first DCI), and the UE needs to monitor the first DCI on the second USS. For example, as shown in the example (a) in Figure 9 , the base station configures the first USS and the second USS within a time slot to have a time domain correspondence. That is, if the UE detects the first DCI on the second USS within a time slot, the UE monitors the second DCI on the first USS corresponding to the second USS within the time slot (the second PDCCH candidate set determined in the first PDCCH candidate set). Alternatively, as shown in the example (b) in Figure 9 , the base station configures the first time interval of the first USS to be 1 time slot, and the first time interval of the second USS to be 2 time slots, and the base station configures the first USS and the second USS within 2 time slots to have a time domain correspondence. That is, if the UE detects the first DCI on the second USS within 2 time slots, the UE continues to monitor the second DCI on the first USS on these 2 time slots (the second PDCCH candidate set determined in the first PDCCH candidate set), and the base station also sends the second DCI on the second PDCCH candidate set on these 2 time slots. In addition, in some scenarios, the first DCI can also be carried on the first PDCCH candidate set. At this time, the first time interval can be understood as the time domain resource range of the first PDCCH candidate set. The UE first monitors the first DCI on the first PDCCH candidate set, and after detecting the first DCI, determines the second PDCCH candidate set according to the method in the above embodiment, and then monitors the second DCI on the second PDCCH candidate set.

[0230] In some embodiments, monitoring the second DCI on the second PDCCH candidate set includes: monitoring the second DCI on the second PDCCH candidate set in the second time interval when the first DCI is detected in the first time interval. There is a corresponding relationship between the first DCI detected in the first time interval and the first PDCCH candidate set for monitoring the second DCI in the second time interval. The first time interval and the second time interval have different start times and the same time length. The start time of the second time interval is later than the start time of the first time interval.

[0231] Exemplarily, the length of the first time interval and the second time interval can be one time slot, or multiple time slots, or one time span, or multiple spans. Exemplarily, the interval between the start time of the second time interval and the start time of the first time interval is one time slot, or multiple time slots, or one time span, or multiple spans. For example, the length of the first time interval and the second time interval is both one time slot, and the start time of the second time interval is one time slot later than that of the first time interval. For example, the length of the first time interval and the second time interval is both two time slots, and the start time of the second time interval is one time slot later than that of the first time interval.

[0232] For example, FIG9 shows a schematic diagram of a time domain relationship between a first DCI and a first PDCCH candidate set. Assume that a base station is configured with a first USS, the first USS is associated with a first CORESET, and the first PDCCH candidate set is a PDCCH candidate set within the time-frequency resource range of the first USS of the first CORESET. That is, the USS includes multiple first PDCCH candidate sets. When a UE detects a first DCI, the first DCI may correspond to one or more first PDCCH candidate sets to be monitored.

[0233] As shown in (c) of Figure 9 , when the length of the first time interval is one time slot, the length of the second time interval is one time slot, and the start time of the second time interval is one time slot later than the start time of the first time interval, in one second time interval, one first DCI corresponds to one first PDCCH candidate set for monitoring the second DCI. As shown in (c) of Figure 9 , the lengths of time slot 1, time slot 2, time slot 3, and time slot 4 are all one time slot. The start time b of the second time interval in time slot 3 is one time slot later than the start time a of the first time interval in time slot 2. The first DCI in time slot 2 corresponds to the second DCI monitored on the first PDCCH candidate set in time slot 3. In some scenarios, there may be more than two first PDCCH candidate sets in one first time interval, which is not limited in this application.

[0234] As shown in (d) of Figure 9 , when the length of the first time interval is 2 time slots, the length of the second time interval is 2 time slots, and the start time of the second time interval is 2 time slots later than the start time of the first time interval, in one second time interval, one first DCI corresponds to two first PDCCH candidate sets for monitoring the second DCI. As shown in (d) of Figure 9 , the lengths of time slot 1, time slot 2, time slot 3, and time slot 4 are all 1 time slot. The start time p of the second time interval in time slot 3 is 2 time slots later than the start time q of the first time interval in time slot 1. The first DCI in time slot 1 corresponds to the second DCI monitored on the first PDCCH candidate set in time slot 3.

[0235] In this way, based on determining the second PDCCH candidate set from the first PDCCH candidate set according to the first DCI, the present application can reduce the blind detection complexity of the UE detecting the second DCI while ensuring the reception performance of the second DCI.

[0236] That is, compared with the prior art in which monitoring the second DCI requires monitoring all PDCCH candidates in the first PDCCH candidate set, the present application determines, based on the monitoring results of the first DCI, that a subset of the first PDCCH candidate set is used to monitor the second DCI. The number of PDCCH candidates monitored by the UE for the second DCI is less than the total number of PDCCH candidates in the first PDCCH candidate set, and the blind detection complexity of the UE monitoring the second DCI is lower.

[0237] Applying the above-mentioned method flow for determining the second PDCCH candidate set from the first PDCCH candidate set, the embodiment of the present application can also determine the count of non-overlapping CCEs of the PDCCH candidates of the first PDCCH candidate set according to a method similar to the method flow, so that when the UE performs over-allocation processing, it can perform over-allocation processing according to the count of non-overlapping CCEs of the PDCCH candidates of the first PDCCH candidate set.

[0238] In some embodiments, the count of non-overlapping CCEs of the PDCCH candidates of the first PDCCH candidate set is determined based on the maximum number of CCEs among the numbers of CCEs corresponding to the multiple PDCCH candidate subsets obtained by traversing multiple possible monitoring results carrying the first DCI, wherein the multiple PDCCH candidate subsets all belong to the first PDCCH candidate set, and one of the multiple PDCCH candidate subsets is the second PDCCH candidate set.

[0239] In some embodiments, the multiple monitoring results carrying the first DCI are multiple optional ALs of the PDCCH candidate carrying the first DCI. The numbers of CCEs corresponding to the multiple PDCCH candidate subsets obtained by traversing the multiple monitoring results of the first DCI include: according to the multiple optional ALs of the PDCCH candidate carrying the first DCI, the number of bits of the first DCI, and the number of bits of multiple possible second DCIs, the numbers of CCEs corresponding to the PDCCH candidate subsets corresponding to each optional AL and each possible number of bits of the second DCI are obtained.

[0240] Exemplarily, determining the count of non-overlapping CCEs of the PDCCH candidates in the first PDCCH candidate set may occur before the UE detects the first DCI. In this case, the UE is not sure on which AL the first DCI will be detected, nor is it sure about the number of bits of the second DCI. The UE may first determine the multiple ALs in the PDCCH candidate set configured by the base station for monitoring the first DCI, as well as the multiple possible numbers of bits of the second DCI, and establish multiple sets of data for each possible AL for monitoring the first DCI and the multiple possible numbers of bits of the second DCI, and determine multiple PDCCH candidate subsets based on the multiple sets of data.

[0241] For example, if the ALs in the PDCCH candidate set monitored for the first DCI are AL2, AL4, and AL8, the number of bits in the second DCI may be 10, 20, or 30, and the number of bits in the first DCI is 8, the UE needs to traverse 12 groups of data to obtain 12 PDCCH candidate subsets, that is, 12 CCE counts. The method for traversing and calculating each PDCCH candidate subset can be found in the method for determining the second PDCCH candidate set above.

[0242] Since different PDCCH candidate subsets correspond to different numbers of CCEs, the maximum number of CCEs of all possible PDCCH candidate subsets is taken as the count of non-overlapping CCEs of the PDCCH candidates in the first PDCCH candidate set.

[0243] For example, assuming the number of bits in the second DCI is known to the UE, for example, as configured by a higher layer, the UE needs to traverse multiple possible ALs for the first DCI. Based on the method for determining the second PDCCH candidate set from the first PDCCH candidate set according to the above embodiment, multiple PDCCH candidate subsets are determined from the first PDCCH candidate set, thereby determining the number of CCEs corresponding to each of the multiple PDCCH candidate subsets. FIG10 is a schematic diagram of multiple possible ways to determine the count of non-overlapping CCEs for PDCCH candidates in the first PDCCH candidate set. As shown in (a) of FIG10 , assuming the AL of the first DCI can be AL1 or AL2. When the AL of the first DCI is AL1, the PDCCH candidate subset determined by the UE is one PDCCH candidate with an AL of AL2 and two CCEs. When the AL of the first DCI is AL2, the PDCCH candidate subset determined by the UE is one PDCCH candidate with an AL of AL4 and four CCEs. In this case, the maximum number of CCEs corresponding to these two PDCCH candidate subsets is four. The number of non-overlapping CCEs of PDCCH candidates in the first PDCCH candidate set is 4.

[0244] As shown in Figure 10(b), assume that the AL of the first DCI may be AL1 or AL2. When the AL of the first DCI is AL1, the number of PDCCH candidates in the PDCCH candidate subset determined by the UE is 2, and the AL is AL2, and the number of CCEs in the PDCCH candidate subset is 4; when the AL of the first DCI is AL2, the number of PDCCH candidates in the PDCCH candidate subset determined by the UE is 2, and the AL is AL4, and the number of CCEs in the PDCCH candidate subset is 8. At this time, the maximum number of CCEs corresponding to these two PDCCH candidate subsets is 8. The count of non-overlapping CCEs of the PDCCH candidates in the first PDCCH candidate set is 8.

[0245] As shown in (c) of Figure 10, it is assumed that the AL of the first DCI may be AL1 or AL2. When the AL of the first DCI is AL1, the number of PDCCH candidates in the PDCCH candidate subset determined by the UE is 2, one of which is a PDCCH candidate with an AL of AL2, and one is a PDCCH candidate with an AL of AL4, and the number of CCEs in the PDCCH candidate subset is 6; when the AL of the first DCI is AL2, the number of PDCCH candidates in the PDCCH candidate subset determined by the UE is 2, one of which is a PDCCH candidate with an AL of AL4, and one is a PDCCH candidate with an AL of AL8, and the number of CCEs in the PDCCH candidate subset is 12. At this time, the maximum number of CCEs corresponding to these two PDCCH candidate subsets is 12. The count of non-overlapping CCEs of the PDCCH candidates in the first PDCCH candidate set is 12.

[0246] In this way, for the UE, the CCE count of the UE monitoring the second DCI does not change as the monitoring result of the first DCI changes, and the reception complexity of the UE monitoring the second DCI is low.

[0247] It should be noted that, on the primary cell, if the first DCI and the second DCI are in different search space sets (or, in different USSs, or, in different PDCCH candidate sets), the UE needs to bundle the two search space sets for over-allocation processing. In some embodiments, when performing over-allocation processing, the UE may monitor both search space sets or neither, and may not monitor only the search space set corresponding to the first DCI and not the search space set corresponding to the second DCI, nor may it monitor only the search space set corresponding to the second DCI and not the search space set corresponding to the first DCI. That is, before the next first DCI cycle, the UE may determine in advance whether to monitor the search space set corresponding to the first DCI and the search space set corresponding to the second DCI based on the CCE count of the search space set corresponding to the first DCI and the CCE count of the search space set corresponding to the second DCI. If the sum of the CCE count of the search space set corresponding to the first DCI and the CCE count of the search space set corresponding to the second DCI is greater than the CCE upper limit, the UE determines not to monitor the first DCI or the second DCI in the next first DCI cycle. Conversely, if the sum of the CCE count of the search space set corresponding to the first DCI and the CCE count of the search space set corresponding to the second DCI is less than or equal to the CCE upper limit, the UE determines to monitor the first DCI and the second DCI in the next first DCI period. This reduces the power consumption of the UE when monitoring PDCCH candidates and also reduces CCE overhead.

[0248] In some embodiments, embodiments of the present application also provide a method for scheduling data channels through two-stage DCI.

[0249] Exemplarily, FIG11 is a flowchart of a method for a base station to schedule a PUSCH through two-stage DCI. The method includes the following processes.

[0250] 111. The base station sends a first DCI to the UE. Correspondingly, the UE receives the first DCI sent by the base station.

[0251] 112. The base station sends a second DCI to the UE. Correspondingly, the UE receives the second DCI sent by the base station.

[0252] 113. The base station receives data carried on the PUSCH sent by the UE. Correspondingly, the UE sends data carried on the PUSCH to the base station.

[0253] After the UE receives the second DCI, it needs to determine the parsing result of the second DCI based on the parsing result of the first DCI, and thus perform PUSCH uplink transmission configuration according to the parsing result of the first DCI and the parsing result of the second DCI, as well as encode and modulate the data, and transmit the data on the PUSCH at the transmission time point of the PUSCH.

[0254] As mentioned above, when two-level DCI is used to schedule PUSCH, there is a minimum time interval between the second DCI and the PUSCH. The UE does not expect the time interval between the second DCI and the data channel to be less than the minimum time interval. When the UE receives the second DCI, if the time interval between the second DCI and the data channel is less than the minimum time interval, the UE considers the second DCI invalid, or does not process the data channel. For example, the UE does not send the uplink data channel scheduled by the first DCI and the second DCI, or does not receive the downlink data channel scheduled by the first DCI and the second DCI.

[0255] Currently, the minimum time interval is fixed. For the UE, after receiving the second DCI, the UE needs to wait until the parsing of the first DCI is completed before it can start parsing the second DCI. That is, the UE needs to parse the second DCI based on the parsing result of the first DCI. If the time interval between the second DCI and the first DCI is too small, the first DCI may not have been parsed when the UE receives the second DCI, which may cause the UE to not have time to parse the second DCI, resulting in a failure to parse the second DCI, resulting in a failure in scheduling PUSCH. Or the UE needs to delay parsing the second DCI, which will cause a delay in the final PUSCH scheduling timing.

[0256] Therefore, in the method of scheduling data channels using two-stage DCI in the present application, the minimum time interval between the second DCI and the data channel scheduled by the second DCI is determined based on the time interval between the first DCI and the second DCI. The data channel is, for example, a PUSCH / PDSCH / channel state information-reference signal (CSI-RS).

[0257] In some embodiments, the first minimum time interval is the minimum time interval between the second DCI and the data channel when the time interval between the first DCI and the second DCI is greater than or equal to a threshold. The second minimum time interval is the minimum time interval between the second DCI and the data channel when the time interval between the first DCI and the second DCI is less than the threshold. The first minimum time interval is less than the second minimum time interval.

[0258] In other words, there are two scenarios:

[0259] Scenario 1: The time interval between the first DCI and the second DCI is greater than or equal to the threshold;

[0260] Scenario 2: The time interval between the first DCI and the second DCI is less than the threshold.

[0261] Taking the PUSCH as an example, when the time interval between the PUSCH and the second DCI scheduled by the base station is greater than or equal to the minimum time interval corresponding to the scenario, the minimum time interval between the second DCI and PUSCH corresponding to scenario one is less than the minimum time interval between the second DCI and PUSCH corresponding to scenario two. The difference between the minimum time intervals in these two scenarios may be a value indicated by the base station or preset by the protocol, or it may be related to the time interval between the first DCI and the second DCI. The smaller the time interval between the first DCI and the second DCI, the greater the difference; the larger the time interval between the first DCI and the second DCI, the smaller the difference.

[0262] Among them, the time interval between the first DCI and the second DCI may be the time interval between the start / end time of the first symbol of the first DCI and the start / end time of the first symbol of the second DCI, or the time interval between the start / end time of the last symbol of the first DCI and the start / end time of the first symbol of the second DCI, or the time interval between the start / end time of the first symbol of the first DCI and the start / end time of the last symbol of the second DCI, or the time interval between the start / end time of the last symbol of the first DCI and the start / end time of the last symbol of the second DCI. This application does not limit the definition of the time interval between the first DCI and the second DCI.

[0263] For example, Figure 12 shows a schematic diagram of the minimum time interval when a base station schedules a PUSCH using two-level DCI. Assuming that the first DCI is carried on a PDCCH candidate at AL2, after determining the second PDCCH candidate set through the above embodiment, the second DCI is detected on a PDCCH candidate at AL4 in the second PDCCH candidate set. When the UE receives the first DCI in step 111, it determines a time point a based on the end time of receiving the first DCI plus a threshold TH. There are two scenarios:

[0264] If the end time of the second DCI received by the UE is later than time point a, it belongs to scenario 1, that is, the time interval between the first DCI and the second DCI is greater than the threshold TH. The UE determines the minimum time interval between the second DCI and the PUSCH and can perform PUSCH uplink transmission according to the minimum time interval currently configured by the network side.

[0265] If the end time of the second DCI received by the UE is earlier than time point a, it belongs to scenario 2, that is, the time interval between the first DCI and the second DCI is less than the threshold TH. The UE can add at least one preset time period on the basis of the minimum time interval between the second DCI and the PUSCH currently configured on the network side to increase the minimum time interval between the second DCI and the PUSCH. In this way, when the time interval between the first DCI and the second DCI is small, if the UE has not completed the parsing of the first DCI when receiving the second DCI, the parsing of the first DCI and the parsing of the second DCI can continue to be completed within the time interval between the second DCI and the PUSCH, and the PUSCH uplink transmission configuration can be performed according to the parsing results of the first DCI and the second DCI, as well as the encoding and modulation processing of the data.

[0266] In this way, the present application can improve the success rate of UE parsing two-level DCI and reduce the implementation complexity of UE by adjusting the minimum time interval between the second DCI and the data channel according to the time interval between the first DCI and the second DCI, thereby improving the transmission efficiency of the two-level DCI scheduling data channel.

[0267] The communication method of the embodiment of the present application is described above in conjunction with Figures 4 to 12. The following description of the communication device of the embodiment of the present application, such as a terminal device, a device for a terminal device (such as a processor, circuit or chip), a network device, or a device for a network device (such as a processor, circuit or chip) is described in conjunction with Figures 13 and 14.

[0268] Figure 13 is a schematic diagram of the structure of a terminal device provided in an embodiment of the present application. This terminal device can be used in the communication system shown in Figure 4 to perform the functions of the terminal device in the above-mentioned method embodiment. For ease of explanation, Figure 13 only shows the main components of the terminal device. As shown in Figure 13, the terminal device 130 includes a processor, memory, control circuitry, an antenna, and input / output devices. The processor is primarily used to process communication protocols and communication data, as well as to control the entire terminal device, execute software programs, and process software program data, for example, to support the terminal device in performing the actions described in the above-mentioned method embodiment. The memory is primarily used to store software programs and data. The control circuit is primarily used to convert baseband signals into radio frequency signals and to process radio frequency signals. The control circuitry and antenna together can also be referred to as a transceiver, which is primarily used to transmit and receive radio frequency signals in the form of electromagnetic waves. Input / output devices, such as a touch screen, display screen, and keyboard, are primarily used to receive data input by the user and output data to the user.

[0269] When a terminal device is powered on, the processor reads the software program from its memory, interprets and executes its instructions, and processes its data. When data needs to be transmitted wirelessly, the processor performs baseband processing on the data to be transmitted and outputs the baseband signal to the RF circuit. The RF circuit then processes the baseband signal and transmits it via the antenna as electromagnetic waves. When data is sent to the terminal device, the RF circuit receives the RF signal via the antenna, converts it into a baseband signal, and outputs the baseband signal to the processor, which converts the baseband signal into data and processes it.

[0270] Those skilled in the art will appreciate that, for ease of explanation, Figure 13 shows only one memory 1302 and one processor 1301. In an actual terminal device, there may be multiple processors 1301 and multiple memories 1302. Memory 1302 may also be referred to as a storage medium or storage device. Memory 1302 may be a storage element on the same chip as processor 1301, i.e., an on-chip storage element, or an independent storage element, which is not limited in this embodiment of the present application.

[0271] As an optional implementation, the terminal device may include a baseband processor and a central processing unit (CPU). The baseband processor is primarily responsible for processing communication protocols and communication data, while the CPU is primarily responsible for controlling the entire terminal device, executing software programs, and processing data from software programs. Processor 1301 in Figure 13 may integrate the functions of both the baseband processor and the CPU. Those skilled in the art will appreciate that the baseband processor and the CPU may also be independent processors interconnected via a bus or other technology. Those skilled in the art will appreciate that a terminal device may include multiple baseband processors to accommodate different network standards, multiple CPUs to enhance its processing capabilities, and that the various components of the terminal device may be connected via various buses. The baseband processor may also be referred to as a baseband processing circuit or a baseband processing chip. The CPU may also be referred to as a central processing circuit or a central processing chip. The functionality for processing communication protocols and communication data may be built into the processor or stored in memory as a software program, with the processor executing the software program to implement the baseband processing functionality.

[0272] In the embodiment of the present application, the antenna 1306 and the control circuit having transceiver functions may be regarded as the transceiver unit 1305 of the terminal device 130, for example, for supporting the terminal device to perform receiving and transmitting functions. The processor 1301 having a processing function may be regarded as the processing unit of the terminal device 130. As shown in FIG13 , the terminal device 130 includes a transceiver unit 1305 and a processor 1301. The transceiver unit 1305 may also be referred to as a transceiver, a transceiver, a transceiver device, etc. Optionally, the device for implementing the receiving function in the transceiver unit 1305 may be regarded as a receiving unit, and the device for implementing the transmitting function in the transceiver unit 1305 may be regarded as a transmitting unit, that is, the transceiver unit 1305 includes a receiving unit and a transmitting unit, the receiving unit may also be referred to as a receiver, an input port, a receiving circuit, etc., and the transmitting unit may be referred to as a transmitter, a transmitter, or a transmitting circuit, etc.

[0273] Processor 1301 may be configured to execute instructions 1303 executed by processor 1301 and instructions 1304 stored in memory 1302 to control transceiver unit 1305 to receive and / or transmit signals, thereby completing the functions of the terminal device in the above-described method embodiment. Processor 1301 also includes an interface for implementing signal input / output functions. As an implementation method, the functions of transceiver unit 1305 may be implemented using a transceiver circuit or a dedicated transceiver chip.

[0274] Figure 14 is a schematic diagram of the structure of a network device provided in an embodiment of the present application, such as a schematic diagram of the structure of a base station. As shown in Figure 14, the base station can be applied to the system shown in Figure 4 to perform the functions of the network device in the above method embodiment. The base station 140 may include one or more DUs 141 and one or more CUs 142. The CU 142 can communicate with the NG core (next generation core network, NC). The DU 141 may include at least one radio frequency unit 1412, at least one processor 1413, and at least one memory 1414. The DU 141 may also include at least one antenna 1411. The DU 141 is mainly used for transmitting and receiving radio frequency signals, converting radio frequency signals into baseband signals, and partial baseband processing. The CU 142 may include at least one processor 1422 and at least one memory 1421. The CU 142 and the DU 141 can communicate through an interface, wherein the control plane interface may be Fs-C, such as F1-C, and the user plane interface may be Fs-U, such as F1-U.

[0275] The CU 142 is primarily responsible for baseband processing and base station control. The DU 141 and CU 142 can be physically located together or separately, i.e., in a distributed base station. The CU 142 is the control center of the base station, also known as a processing unit, and is primarily responsible for performing baseband processing functions. For example, the CU 142 can be used to control the base station to execute the network device operation procedures described in the above-described method embodiments.

[0276] Specifically, baseband processing on the CU and DU can be divided according to the protocol layers of the wireless network. For example, the functions of the packet data convergence protocol (PDCP) layer and above are set in the CU, and the functions of the protocol layers below the PDCP, such as the radio link control (RLC) layer and the media access control (MAC) layer, are set in the DU. For another example, the CU implements the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers, while the DU implements the functions of the radio link control (RLC), medium access control (MAC), and physical (PHY) layers.

[0277] In addition, optionally (not shown), base station 140 may include one or more antennas, one or more radio frequency units, one or more DUs, and one or more CUs. The DU may include at least one processor and at least one memory, the at least one antenna and at least one radio frequency unit may be integrated into one antenna device, and the CU may include at least one processor and at least one memory.

[0278] In one example, the CU142 may be composed of one or more single boards, and the multiple single boards may jointly support a wireless access network with a single access indication (such as a 5G network), or may respectively support wireless access networks with different access standards (such as an LTE network, a 5G network, or other networks). The memory 1421 and the processor 1422 may serve one or more single boards. That is, a memory and a processor may be separately set on each single board. It is also possible that multiple single boards share the same memory and processor. In addition, necessary circuits may be provided on each single board. The DU141 may be composed of one or more single boards, and the multiple single boards may jointly support a wireless access network with a single access indication (such as a 5G network), or may respectively support wireless access networks with different access standards (such as an LTE network, a 5G network, or other networks). The memory 1414 and the processor 1413 may serve one or more single boards. That is, a memory and a processor may be separately set on each single board. It is also possible that multiple single boards share the same memory and processor. In addition, necessary circuits may be provided on each single board.

[0279] The terminal devices and network devices in the above-mentioned various apparatus embodiments may completely correspond to the terminal devices or network devices in the method embodiments, and the corresponding steps are performed by corresponding modules or units. For example, when the apparatus is implemented as a chip, the receiving unit may be an interface circuit of the chip used to receive signals from other chips or devices. The above-mentioned unit for sending is an interface circuit of the apparatus, used to send signals to other devices. For example, when the apparatus is implemented as a chip, the sending unit is an interface circuit of the chip used to send signals to other chips or devices.

[0280] It should be understood that the processor in the embodiment of the present application may be a CPU, and the processor may also be other general-purpose processors, digital signal processing (DSP), application specific integrated circuit (ASIC), field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0281] It should also be understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0282] The terminal devices and network devices in the above-mentioned various apparatus embodiments may completely correspond to the terminal devices or network devices in the method embodiments, and the corresponding steps are performed by corresponding modules or units. For example, when the apparatus is implemented as a chip, the receiving unit may be an interface circuit of the chip used to receive signals from other chips or devices. The above-mentioned unit for sending is an interface circuit of the apparatus, used to send signals to other devices. For example, when the apparatus is implemented as a chip, the sending unit is an interface circuit of the chip used to send signals to other chips or devices.

[0283] An embodiment of the present application also provides a communication system, which includes: the above-mentioned network device (wireless access network device) and terminal equipment.

[0284] The present invention also provides a computer-readable medium for storing computer program code, wherein the computer program includes instructions for executing a method executed by a network device or a terminal device in the communication method described above. The computer-readable medium may be ROM or RAM, which is not limited in the present invention.

[0285] The present application also provides a computer program product, which includes instructions. When the instructions are executed, the terminal device and the network device respectively perform the operations of the terminal device and the network device corresponding to the above method.

[0286] The present application also provides a system-on-chip (SoC), comprising a processing unit and a communication unit. The processing unit may be, for example, a processor, and the communication unit may be, for example, an input / output interface, a pin, or a circuit. The processing unit may execute computer instructions to cause the communication device implemented by the SoC to perform the operations of the terminal device and the network device in the methods provided in the embodiments of the present application.

[0287] Optionally, any one of the communication devices provided in the above embodiments of the present application may include the system chip.

[0288] Optionally, the computer instructions are stored in a storage unit.

[0289] Optionally, the storage unit is a storage unit within the chip, such as a register, cache, etc. The storage unit may also be a storage unit located outside the chip within the communication device, such as a ROM or other type of static storage device that can store static information and instructions, RAM, etc. The processor mentioned in any of the above may be a CPU, a microprocessor, an ASIC, or one or more integrated circuits for controlling the execution of the program of the above-mentioned feedback information transmission method. The processing unit and the storage unit may be decoupled and respectively provided on different physical devices, and connected by wired or wireless means to implement the respective functions of the processing unit and the storage unit to support the system chip to implement the various functions in the above-mentioned embodiments. Alternatively, the processing unit and the memory may also be coupled on the same device. It should be understood that the processor in the embodiments of the present application may be a CPU, and the processor may also be other general-purpose processors, DSPs, ASICs, FPGAs or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0290] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0291] The above embodiments can be implemented in whole or in part by software, hardware (such as circuits), firmware or any other combination. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer program are loaded or executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (such as infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that contains one or more available media sets. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a tape), an optical medium (for example, a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state drive.

[0292] Various objects such as various messages / information / equipment / network elements / systems / devices / actions / operations / processes / concepts that may appear in this application are named. It can be understood that these specific names do not constitute a limitation on the relevant objects. The names assigned may change with factors such as scenarios, contexts or usage habits. The understanding of the technical meaning of the technical terms in this application should be mainly determined from the functions and technical effects embodied / executed in the technical solutions.

[0293] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0294] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0295] The units described as separate components may or may not be physically separate, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple places. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0296] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0297] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0298] The above content is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for transmitting a control channel, characterized in that: The method comprises: receiving indication information, where the indication information is used to indicate a first physical downlink control channel candidate PDCCH candidate set; Receiving first downlink control information DCI; A second DCI is monitored on a second PDCCH candidate set, where the second PDCCH candidate set is determined according to the first DCI, and the second PDCCH candidate set belongs to the first PDCCH candidate set.

2. The method according to claim 1, characterized in that Monitoring the second DCI on the second PDCCH candidate set includes: In a case where the first DCI is detected in a first time interval, the second DCI is monitored on the second PDCCH candidate set in the first time interval.

3. A control channel transmission method, characterized in that: The method comprises: Sending indication information, where the indication information is used to indicate a first PDCCH candidate set; Sending a first DCI, where the first DCI is used to indicate a second PDCCH candidate set, where the second PDCCH candidate set belongs to the first PDCCH candidate set; Send a second DCI on the second PDCCH candidate set.

4. The method according to any one of claims 1 to 3, characterized in that: The first DCI includes an indication of a number of bits of the second DCI.

5. The method according to any one of claims 1 to 4, characterized in that: The second PDCCH candidate set is determined according to an aggregation level AL of the PDCCH candidates carrying the first DCI.

6. The method according to claim 5, characterized in that The PDCCH candidates in the second PDCCH candidate set are PDCCH candidates in the first PDCCH candidate set whose AL is greater than or equal to the first AL; The first AL is determined according to the number of bits of the first DCI, the AL of the PDCCH candidate carrying the first DCI, and the number of bits of the second DCI; or, the first AL is determined according to the AL of the PDCCH candidate carrying the first DCI and the number of carriers scheduled by the second DCI.

7. The method according to claim 6, characterized in that The number of PDCCH candidates in the second PDCCH candidate set is less than or equal to a preset total number.

8. The method according to claim 7, characterized in that The PDCCH candidates in the second PDCCH candidate set are the preset total number of PDCCH candidates after sorting the PDCCH candidates in the first PDCCH candidate set whose AL is greater than or equal to the first AL from small to large according to AL.

9. The method according to claim 7 or 8, characterized in that: The PDCCH candidate blind detection count of the first PDCCH candidate set is determined according to the preset total number.

10. The method according to claim 6, characterized in that The PDCCH candidates in the second PDCCH candidate set are PDCCH candidates corresponding to a number of ALs of a first preset level after the ALs in the first PDCCH candidate set whose ALs are greater than or equal to the first AL are sorted from small to large according to ALs; The number of PDCCH candidates corresponding to any one AL in the second PDCCH candidate set does not exceed the preset number corresponding to any one AL.

11. The method according to claim 10, characterized in that The PDCCH candidate blind detection count of the first PDCCH candidate set is determined according to the preset level number and the preset number corresponding to each AL in the second PDCCH candidate set.

12. The method according to claim 6, characterized in that The number of ALs of the PDCCH candidates in the second PDCCH candidate set is less than or equal to a preset level number.

13. The method according to claim 12, characterized in that The PDCCH candidates in the second PDCCH candidate set are The PDCCH candidates corresponding to the first preset number of ALs whose AL is greater than or equal to the first AL are sorted from small to large according to the AL.

14. The method according to claim 13, characterized in that The PDCCH candidate blind detection count of the first PDCCH candidate set is determined according to the preset level number.

15. The method according to any one of claims 1 to 14, characterized in that: The count of non-overlapping control channel elements CCE of the PDCCH candidates of the first PDCCH candidate set is determined according to the maximum number of CCEs among the numbers of CCEs corresponding to the multiple PDCCH candidate subsets respectively obtained by traversing the multiple possible monitoring results carrying the first DCI; The multiple PDCCH candidate subsets all belong to the first PDCCH candidate set, and one PDCCH candidate subset among the multiple PDCCH candidate subsets is the second PDCCH candidate set.

16. The method according to claim 15, characterized in that The multiple monitoring results carrying the first DCI are multiple optional ALs of the PDCCH candidate carrying the first DCI; The traversal of the multiple monitoring results of the first DCI to obtain the CCE numbers corresponding to the multiple PDCCH candidate subsets respectively include: According to multiple optional ALs of the PDCCH candidate carrying the first DCI, the number of bits of the first DCI and multiple possible numbers of bits of the second DCI, the number of CCEs corresponding to the PDCCH candidate subsets corresponding to each optional AL and each possible number of bits of the second DCI are obtained.

17. The method according to any one of claims 1 to 16, characterized in that: The minimum time interval between the second DCI and the data channel scheduled by the second DCI is determined according to the time interval between the first DCI and the second DCI.

18. The method according to claim 17, characterized in that The first minimum time interval is the minimum time interval between the second DCI and the data channel when the time interval between the first DCI and the second DCI is greater than or equal to the threshold; The second minimum time interval is the minimum time interval between the second DCI and the data channel when the time interval between the first DCI and the second DCI is less than the threshold; The first minimum time interval is smaller than the second minimum time interval.

19. A communication device, characterized in that: include: A receiving unit, configured to receive indication information, where the indication information is used to indicate a first physical downlink control channel candidate PDCCH candidate set; The receiving unit is further configured to receive first downlink control information DCI; The monitoring unit is configured to monitor a second DCI on a second PDCCH candidate set, where the second PDCCH candidate set is determined according to the first DCI, and the second PDCCH candidate set belongs to the first PDCCH candidate set.

20. A communication device, characterized in that: include: a sending unit, configured to send indication information, where the indication information is used to indicate a first PDCCH candidate set; The sending unit is further used to send a first DCI, where the first DCI is used to indicate a second PDCCH candidate set, where the second PDCCH candidate set belongs to the first PDCCH candidate set; The sending unit is further configured to send a second DCI on the second PDCCH candidate set.

21. A communication system, characterized in that: Comprising the communication device as claimed in claim 19 and the communication device as claimed in claim 20.

22. A computer-readable storage medium, characterized in that: The method comprises computer instructions, which, when executed on an electronic device, cause the electronic device to execute the method according to any one of claims 1 to 18.

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