Communication device

Abstract

To provide a technique capable of precisely detecting control information by a terminal.SOLUTION: A communication device performs the following steps step by step: a first series of processing of aligning the size of control information between a first format for a first search space and a second format for a second search space (Step 4); and a second series of processing of aligning the size of control information among the third format, the first format or the second format (Procedure B).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a communication device.

Background Art

[0002] A communication system called the fifth-generation mobile communication system (5G) is under consideration. For example, increasing communication traffic, increasing the number of connected terminals, and flexibly providing functions for each individual use case that requires high reliability and low latency are being considered.

[0003] As an example of a typical service, there are three types: enhanced Mobile Broadband (eMBB), massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communication (URLLC).

[0004] The 3GPP (Third Generation Partnership Project) (registered trademark), which is an international standards organization, is considering the advancement of communication systems from both aspects of the advancement of the LTE (Long Term Evolution) system and New Radio (NR).

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

[0006] There is room for consideration regarding the size adjustment of control information for which multiple types of formats are defined in order for a terminal to appropriately detect control information transmitted from a base station.

[0007] Non-limiting examples of the present disclosure contribute to providing an improved base station, terminal, and communication method that enable a terminal to appropriately detect control information.

[0008] A base station according to one aspect of the present disclosure includes a control circuit that sequentially performs a first process of aligning the size of control information between a first format for a first search space and a second format for a second search space, and a second process of aligning the size of the control information between a third format and the first format or the second format; and a transmission circuit that transmits the control information.

[0009] A terminal according to one aspect of the present disclosure includes a control circuit that controls reception of the control information based on information regarding application of a first process of aligning the size of control information between a first format and a second format, and a second process of aligning the size of the control information between a third format and the first format or the second format, and a reception circuit that receives the control information in response to the control.

[0010] A communication method for a base station according to one aspect of the present disclosure sequentially performs a first process of aligning the size of control information between a first format for a first search space and a second format for a second search space, and a second process of aligning the size of the control information between a third format and the first format or the second format, and transmits the control information.

[0011] A communication method for a terminal according to an aspect of the present disclosure controls reception of the control information based on information regarding application of a first process of aligning the size of control information between a first format for a first search space and a second format for a second search space, and a second process of aligning the size of the control information between a third format and the first format or the second format, and receives the control information in response to the control.

[0012] Note that these general or specific aspects may be implemented in a system, apparatus, method, integrated circuit, computer program, or recording medium, or may be implemented in any combination of a system, apparatus, method, integrated circuit, computer program, and recording medium.

[0013] According to an aspect of the present disclosure, a terminal can appropriately detect control information.

[0014] Further advantages and effects in an aspect of the present disclosure will be clarified from the specification and drawings. Such advantages and / or effects are provided by some embodiments and the features described in the specification and drawings respectively, but not necessarily all are provided in order to obtain one or more identical features.

Brief Description of Drawings

[0015]

Figure 1

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Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described in detail with appropriate reference to the drawings. However, a more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and duplicate descriptions of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art.

[0017] Note that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and it is not intended to limit the subject matter described in the claims by these.

[0018] In NR, a control resource set (CORESET) and a search space are set for a terminal (for example, a UE (User Equipment)) as a PDCCH area, which is one of the control channels for transmitting DCI (downlink control information). The UE monitors the search space, which is the position of PDCCH (physical downlink control channel) candidates in the CORESET, and detects DCI. The following eight types of DCI formats are prepared (for example, Non-Patent Document 2).

[0019] DCI format 0_0 for the scheduling PUSCH DCI format 0_1 for the scheduling PUSCH DCI format 1_0 for the scheduling PDSCH DCI format 1_1 for the scheduling PDSCH DCI format 2_0 for notifying slot format DCI format 2_1 for preemption DCI format 2_2 for TPC commands for PUCCH and PUSCH DCI format 2_2 for a group of TPC commands for SRS

[0020] Note that "PUSCH" is an abbreviation of "physical uplink shared channel", and "PDSCH" is an abbreviation of "physical downlink shared channel". Also, "TPC" is an abbreviation of "transmission power control", and "SRS" is an abbreviation of "sounding reference signal". In addition, hereinafter, " / " in notations such as "DCI format 0_0 / 1_0" and "DCI format 0_1 / 1_1" means "and / or".

[0021] In DCI format 0_0 / 1_0, the size of the DCI format may be different in the CSS (common search space) and the USS (UE specific search space). Also, it is defined that DCI format 2_2 and DCI format 2_2 are of the same size as DCI format 0_0 / 1_0 in the CSS. Note that one of the CSS and the USS may correspond to an example of the first search space, and the other of the CSS and the USS may correspond to an example of the second search space.

[0022] The UE monitors the DCI format that is set to be monitored by the base station (e.g., gNB). The base station can also cause different DCI formats to be monitored for each UE. In Non-Patent Document 2, it is stipulated that the UE does not need to monitor more than four DCI formats of different sizes. Also, for the DCI format masked (or scrambled, in other words) by the C-RNTI (cell-radio network temporary identifier), the UE does not need to monitor more than three DCI formats of different sizes. Therefore, the base station sets the DCI format in accordance with these stipulations.

[0023] In URLLC, ultra-reliability and low latency are required, so a reduction in the error rate of the PDSCH, which is an example of the downlink (DL) data channel, is required. To reduce the error rate of the data channel, it is required to reduce the error rate of the PDCCH, which is an example of the control channel. Since the UE can correctly recognize the allocation of the PDSCH by correctly detecting the PDCCH, the error rate of the PDSCH can be reduced.

[0024] As an example of a method for reducing the error rate of PDCCH, it is considered to reduce the size of DCI transmitted in PDCCH by about 10 to 16 bits compared to DCI format 0_0 / 1_0 (for example, Non-Patent Document 1). On the other hand, depending on the upper layer settings, it is also considered to make the fields included in DCI variable and have a size larger than DCI format 0_0 / 1_0.

[0025] Here, when the base station sets a DCI format with a size different from the existing (or legacy) DCI format, the number of times the UE attempts to detect DCI, in other words, the number of times of blind detection (BD) may increase.

[0026] In the embodiments described below, an example of realizing appropriate DCI detection in the UE when the base station sets a DCI format with a size different from the existing DCI format will be described.

[0027] (Embodiment 1) In Embodiment 1, the sizes between DCI formats are adjusted step by step. For example, in the first-stage process, the sizes of the DCI format 0_0 / 1_0 of CSS and the DCI format 0_0 / 1_0 of USS are made the same as each other. In the second-stage process, the size of the DCI format (hereinafter, referred to as "new DCI format" for convenience) being considered for extension for URLLC and the size of other DCI format(s) are made the same as each other. Note that the process of making the sizes between DCI formats the same as each other may be regarded as matching, making equal, or aligning the sizes of both.

[0028] According to the two-stage process, when the total number of different DCI format sizes is less than the reference in the first-stage process, the second-stage process can be skipped (or bypassed). By being able to skip the second-stage process, the size of DCI can be maintained or kept at a size suitable for operation.

[0029] Therefore, for example, the error rate of PDCCH can be reduced. By reducing the error rate of PDCCH, the error rate of PDSCH can also be reduced. Thus, the reception quality of PDCCH and PDSCH at the UE can be improved, and the DL throughput can be increased.

[0030] (An example of the method for determining the size of DCI format when not considering the new DCI format) In DCI format 0_0 / 1_0, the number of bits used for frequency domain resource assignment may vary depending on the value of the assumed bandwidth (e.g., bandwidth part, BWP). Therefore, the size of DCI format 0_0 / 1_0 is determined according to the value of BWP. Also, in DCI format 0_1 / 1_1, in addition to the frequency domain resource assignment bits, there is a field with a variable number of bits according to the signaling of the upper layer. Therefore, the size of the DCI format is also variable according to the signaling of the upper layer.

[0031] When not considering the new DCI format, as an example of the method for determining the size of DCI format, the method illustrated in the flowchart of FIG. 12 is considered. Five steps (Steps 0-4) are illustrated in FIG. 12.

[0032] In Step 0, the sizes of DCI format 0_0 and DCI format 1_0 of CSS are determined. For example, the size of DCI format 0_0 is determined based on the value of the initial UL BWP (Bandwidth part). Note that "UL" is an abbreviation of "uplink".

[0033] On one hand, the size of DCI format 1_0 is determined based on the bandwidth of CORESET#0 or the value of the initial DL BWP. When the size of DCI format 0_0 is different from that of DCI format 1_0, for example, the size of DCI format 0_0 is adjusted (or aligned) to the size of DCI format 1_0.

[0034] For example, when the size of DCI format 0_0 is smaller than that of DCI format 1_0, bit 0 is added to DCI format 0_0. When the size of DCI format 0_0 is larger than that of DCI format 1_0, for DCI format 0_0, a part of the resource allocation bits in the frequency direction is deleted.

[0035] Note that "adding" bit 0 may be read as other terms such as "padding", "inserting", or "prepending". "Deleting" a bit may be read as other terms such as "truncating" or "dropping".

[0036] In Step 1, the sizes of DCI format 0_0 and DCI format 1_0 of the USS are determined. For example, the size of DCI format 0_0 is determined based on the value of the active UL BWP. The size of DCI format 1_0 is determined based on the value of the active DL BWP. When the size of DCI format 0_0 is different from that of DCI format 1_0, in order to align the DCI format with the smaller size to the DCI format with the larger size, bit 0 is added to the DCI format with the smaller size.

[0037] In step 2, the sizes of DCI format 0_1 and DCI format 1_1 of the USS are determined. The size of DCI format 0_1 is determined based on the value of the active UL BWP. Note that the size of DCI format 0_1 is defined as a size different from the size of DCI format 0_0 of the USS. The size of DCI format 1_1 is determined based on the value of the active DL BWP. Note that the size of DCI format 1_1 is defined as a size different from the size of DCI format 1_0 of the USS.

[0038] In step 3, the following two conditions are checked. If both conditions are satisfied, the process may end. If either one of the two conditions is not satisfied, the process proceeds to step 4. (Condition A) The total number of different DCI format sizes is not greater than X1. (Condition B) The total number of different DCI format sizes monitored using C-RNTI is not greater than X2. Note that both X1 and X2 are integers of 1 or more. In Non-Patent Document 2, X1 = 4 and X2 = 3.

[0039] In step 4, size adjustment is performed to match the sizes of DCI format 0_0 / 1_0 of the CSS and the sizes of DCI format 0_0 / 1_0 of the USS with each other. For example, the size of DCI format 0_0 / 1_0 of the CSS is aligned with the size of DCI format 0_0 / 1_0 of the USS by the size adjustment. The same BWP as that of the CSS is assumed for DCI format 0_0 / 1_0 of the USS.

[0040] (Operation Example 1-1) Next, operation example 1-1 according to Embodiment 1 will be described with reference to the flowchart of FIG. 1.

[0041] As illustrated in FIG. 1, in Operation Example 1-1, for example, between Step 2 and Step 3 shown in FIG. 12, Step 2.1 is executed. Step 2.1 corresponds to a process of determining the size of the new DCI format. Also, in Operation Example 1-1, after Step 4 shown in FIG. 12, Procedure A (Step 5) and Procedure B (Step 6) are executed.

[0042] Procedure A (Step 5) corresponds to a process of determining whether to align the size of the new DCI format with other DCI formats. Procedure B (Step 6) corresponds to a process of aligning the size of the new DCI format with other DCI format(s) (hereinafter sometimes referred to as "size adjustment process") according to the determination result of "aligning the size" in Procedure A (Step 5). An example of "other DCI format(s)" will be described later. In Operation Example 1-1, it is assumed that the new DCI format is masked (scrambled) by an RNTI different from C-RNTI, for example.

[0043] In Step 2.1 of FIG. 1, the size of the new DCI format is determined. The new DCI format is monitored by a terminal (e.g., UE) that has received a monitor instruction from an upper layer at a base station (e.g., gNB). The new DCI format is assumed to be monitored in one or both of USS and CSS. Regarding in which search space of USS and CSS the UE monitors the new DCI format, for example, the UE may be instructed by signaling from the upper layer.

[0044] Also, it is possible to assume that the new DCI format is supported only for one of USS and CSS (for example, USS). Also, it is possible to assume that the New DCI format supports one or both of a control signal (for example, DL assignment) for allocating DL PDSCH and a control signal (for example, UL grant) for allocating UL PUSCH. Therefore, for the UE, it is assumed that both control signals are monitored and that only one of the two control signals is monitored. Note that the "control signal" may be read as "control information".

[0045] Also, the size of the New DCI format may vary depending on a field set by a higher layer. For example, the size of the DCI format is variable depending on the number of bits used in each of the 20 fields illustrated below.

[0046] <An example of a field set for the New DCI format> (1)Frequency domain resource assignment (2)Time domain resource assignment (3)Modulation and coding scheme (4)HARQ process number (5)Redundancy version (6)PUCCH resource indicator (7)PDSCH-to-HARQ_feedback timing indicator (8)Downlink assignment index (9)Antenna port(s) (10)Transmission configuration indication (11)Rate matching indicator (12) SRS request (13) PRB bundling size indicator (14) Carrier indicator (15) CSI request (16) ZP CSI-RS triggering (17) Beta offset indicator (18) SRS resource indicator (19) Repetition factor (20) Priority indication

[0047] Note that "HARQ" is an abbreviation of "hybrid automatic repeat request", "PRB" is an abbreviation of "physical resource block", "CSI" is an abbreviation of "channel state information", and "ZP CSI-RS" is an abbreviation of "zero power channel state information - reference signal".

[0048] The settings for the above fields may be the same or different between DL assignment and DL grant. Also, depending on the settings of UL BWP and DL BWP, the sizes may be different. If the BWP is different between CSS and USS, the size of the New DCI format may also be different between CSS and USS.

[0049] After Step 2.1, Step 3 is executed. After Step 3 is determined to be NO and Step 4 is executed, Step 5 (Procedure A) is executed. In Step 5 (Procedure A), for example, condition A "the total number of different DCI format sizes is not greater than X1" is confirmed.

[0050] Note that, in Operation Example 1-1, since it is assumed that the new DCI format is masked by an RNTI different from the C-RNTI, in Step 5 (Procedure A), the determination condition B regarding X2 in Step 3 (the total number of sizes of different DCI formats monitored using the C-RNTI is not larger than X2) does not need to be included. When the new DCI format is masked by the C-RNTI, the determination condition B regarding X2 in Step 3 may be included in Step 5 (Procedure A).

[0051] In Step 5 (Procedure A), if it is determined that condition A is satisfied (Step 5; YES), the process of Operation Example 1-1 may end. On the other hand, if it is determined that condition A is not satisfied (Step 5; NO), the process proceeds to Step 6 (Procedure B).

[0052] In Step 6 (Procedure B), the size of the new DCI format is aligned with the size(s) of other DCI format(s). For example, the size of the new DCI format is aligned with the size of one or more of the following exemplified DCI format(s). ·DCI format 0_0 / 1_0 in CSS ·DCI format 0_0 / 1_0 in USS ·DCI format 0_1 in USS ·DCI format 1_1 in USS

[0053] Also, when Step 4 is performed before transitioning to Procedure B (Step 6), the DCI format 0_0 / 1_0 in CSS and the DCI format 0_0 / 1_0 in USS are considered to have the same size.

[0054] Also, in Procedure B, when the size of the new DCI format is aligned with the sizes of other DCI format(s), it can also be understood that the sizes of other DCI format(s) are aligned with the size of the new DCI format.

[0055] As described above, in Operation Example 1-1, after the process of aligning the sizes of the CSS's DCI format 0_0 / 1_0 and the USS's DCI format 0_0 / 1_0 with each other (Step 4), the process of aligning the size of the new DCI format with other DCI formats (Step 6; Procedure B) is performed. In other words, the process of aligning the sizes of the CSS's DCI format 0_0 / 1_0 and the USS's DCI format 0_0 / 1_0 is performed before the process of aligning the new DCI format with the sizes of other DCI formats.

[0056] Therefore, in the first determination process (Step 3), if it is determined that the total number of DCI formats with different sizes exceeds the specified value X1 (NO), the process of "aligning the size of the CSS's DCI format 0_0 / 1_0 and the size of the USS's DCI format 0_0 / 1_0" in Step 4 is preferentially performed.

[0057] Therefore, in the second determination process (Step 5), if it is determined that the total number of DCI formats with different sizes is within the specified value X1, Step 6 (Procedure B) is skipped (or bypassed).

[0058] By skipping Step 6 (Procedure B), the size of the new DCI format does not need to be changed (or adjusted). Therefore, for example, if a DCI with a size smaller than that of other DCI formats (which may be conveniently referred to as "Compact DCI") is set for the new DCI format for URLLC, the new DCI format can be operated with the smaller size. Thus, the reception quality of the new DCI format at the UE can be maintained. In other words, it is possible to suppress or prevent the reception quality of the new DCI format at the UE from deteriorating due to the size adjustment of the new DCI format.

[0059] (Operation Example 1-2) Next, the operation example 1-2 according to Embodiment 1 will be described with reference to the flowchart of FIG. 2.

[0060] In operation example 1-2, different from operation example 1-1, before Step 4 (for example, between Step 2 and Step 3), a determination process (Step 2.2; Procedure A) and a size adjustment process (Step 2.3; Procedure B) are executed.

[0061] Step 2.2 (Procedure A) corresponds to a process of determining whether to align the size of the new DCI format with that of other DCI formats, and Step 2.3 (Procedure B) corresponds to a process of aligning the size of the new DCI format with that of other DCI formats. In FIG. 2, Step 2.1 is the same as Step 2.1 in operation example 1-1 of FIG. 1.

[0062] Also in operation example 1-2, it is assumed that, similar to operation example 1-1, the new DCI format is masked (scrambled) by an RNTI different from the C-RNTI. Hereinafter, an operation example focusing on the processes (Step 2.2 and Step 2.3) different from operation example 1-1 will be described.

[0063] In Step 2.2 (Procedure A), for example, condition A “the total number of different DCI format sizes is not greater than X1” is confirmed.

[0064] Note that in Operation Example 1-2 as well, similar to Operation Example 1-1, since it is assumed that the new DCI format is masked by an RNTI different from the C-RNTI, in Step 2.2 (Procedure A), the determination condition B regarding X2 (the total number of different DCI format sizes monitored using the C-RNTI is not greater than X2) may not be included. When the new DCI format is masked by the C-RNTI, the determination condition B regarding X2 may be included in Step 2.2 (Procedure A).

[0065] In Step 2.2 (Procedure A), if it is determined that condition A is satisfied (Step 2.2; YES), the processing of Operation Example 1-2 may end. On the other hand, if it is determined that condition A is not satisfied (Step 2.2; NO), the processing proceeds to Step 2.3 (Procedure B).

[0066] In Step 2.3 (Procedure B), similar to Step 6 in FIG. 1, the size of the new DCI format is aligned with the size(s) of other DCI format(s). For example, the size of the new DCI format is aligned with the size of one or more of the following exemplified DCI format(s). · DCI format 0_0 / 1_0 in CSS · DCI format 0_0 / 1_0 in USS · DCI format 0_1 in USS · DCI format 1_1 in USS

[0067] In Operation Example 1-2, after Step 2.3 (Procedure B), Step 3 and Step 4 illustrated in FIG. 1 are executed.

[0068] As described above, in Operation Example 1-2, before Step 4 illustrated in FIG. 1, a process (Step 2.3; Procedure B) of aligning the size of the new DCI format with the size of other DCI formats is performed. In other words, the process of aligning the new DCI format with the size of other DCI formats is performed before the process of aligning the sizes of the CSS's DCI format 0_0 / 1_0 and the USS's DCI format 0_0 / 1_0.

[0069] Therefore, in the first determination process (Step 2.2), when it is determined that the total number of DCI formats with different sizes exceeds the specified value X1 (NO), the process of "aligning the size of the new DCI format with the size of other DCI formats" in Step 2.3 is preferentially performed.

[0070] Accordingly, in Step 2.2 (Procedure A), when it is determined that the total number of DCI formats with different sizes is within the specified value X1, Step 4 (Procedure B) is skipped (or bypassed).

[0071] By skipping Step 4, the sizes of the CSS's DCI format 0_0 / 1_0 and the USS's DCI format 0_0 / 1_0 do not have to be aligned. Therefore, for example, when the BWP of the USS is wider than the BWP of the CSS, the BWP that can be indicated in the USS's DCI format 0_0 / 1_0 can be set as an individual BWP for the USS without aligning it with the BWP of the CSS. Thus, for example, flexible resource allocation is possible in the USS's DCI format 0_0 / 1_0.

[0072] (Operation Example 1-3) Next, operation examples 1-3 according to Embodiment 1 will be described with reference to the flowchart of FIG. 3. It may be understood that operation examples 1-3 correspond to modified examples combining the elements of operation examples 1-1 and 1-2 described above.

[0073] For example, as shown in FIG. 3, in operation example 1-3, before Step 2.2 of operation example 1-2 (for example, between Step 2.1 and Step 2.2), Step 2.1.1 is executed. In Step 2.1.1, it is determined (or confirmed) whether the condition B "the total number of sizes of different DCI formats monitored using C-RNTI is not greater than X2" is satisfied. This condition B corresponds to a part of the conditions in Step 3 in operation example 1-2. Therefore, in operation example 1-3, in Step 3.1, condition A among conditions A and B is confirmed.

[0074] If it is determined in Step 2.1.1 that condition B is satisfied (Step 2.1.1; YES), the process proceeds to Step 2.2 (Procedure A). On the other hand, if it is determined in Step 2.1.1 that condition B is not satisfied (Step 2.1.1; NO), the process proceeds to Step 4.1. Step 4.1 is the same process as Step 4 in operation examples 1-1 and 1-2.

[0075] If it is determined in Step 2.2 (Procedure A) that condition A is satisfied (Step 2.2; YES), the process of operation example 1-3 may end. On the other hand, if it is determined that condition A is not satisfied (Step 2.2; NO), the process proceeds to Step 2.3 (Procedure B).

[0076] In Step 2.3 (Procedure B), similar to operation example 1-2, the size of the new DCI format is aligned with the sizes of other DCI format(s).

[0077] After this size adjustment, in Step 3.1, it is determined (or confirmed) again whether Condition A, "the total number of different DCI format sizes is not greater than X1", is satisfied. If it is determined that Condition A is satisfied (Step 3.1; YES), the process may end. If it is determined that Condition A is not satisfied (Step 3.1; NO), the process proceeds to Step 4.

[0078] In Step 4 and Step 4.1, similar to Operation Example 1-1 and Operation Example 1-2, for example, the size of the CSS's DCI format 0_0 / 1_0 and the size of the USS's DCI format 0_0 / 1_0 are aligned.

[0079] After Step 4, the process of Operation Example 1-3 may end. On the other hand, after Step 4.1, in Step 5 (Procedure A), for example, Condition A, "the total number of different DCI format sizes is not greater than X1", is determined (or confirmed).

[0080] In Step 5 (Procedure A), if it is determined that Condition A is satisfied (Step 5; YES), the process of Operation Example 1-3 may end. On the other hand, if it is determined that Condition A is not satisfied (Step 5; NO), the process proceeds to Step 6 (Procedure B).

[0081] In Step 6 (Procedure B), the size of the new DCI format and the size of the other DCI format(s) are aligned. After Step 6 (Procedure B), the process of Operation Example 1-3 may end.

[0082] The operation examples 1-3 have been described above. In operation examples 1-2, since Step 2.2 (Procedure A) and Step 2.3 (Procedure B) are executed before Step 4, regardless of the total number of different DCI format sizes to be monitored using C-RNTI, when the total number of different DCI format sizes is greater than X1, the size of the new DCI format is adjusted.

[0083] In contrast, in operation example 1-3, before Step 4 and Step 4.1, it is confirmed whether a part of the condition (condition B) in Step 3, that is, "the total number of different DCI format sizes to be monitored using C-RNTI is not greater than X2", is satisfied.

[0084] When it is determined that condition B is not satisfied, in Step 4 or Step 4.1, the sizes of the CSS's DCI format 0_0 / 1_0 and the USS's DCI format 0_0 / 1_0 are aligned. The reason for checking condition B prior to condition A in this way is that when the new DCI format is not masked by C-RNTI, the size adjustment between different DCI formats monitored using C-RNTI cannot be achieved by aligning the size of the new DCI format with other DCI format(s).

[0085] Also, by aligning the sizes of the CSS's DCI format 0_0 / 1_0 and the USS's DCI format 0_0 / 1_0, the total number of different DCI format sizes can be reduced. Therefore, as described in operation example 1-1, there may be a case where the processing can be terminated by skipping from Step 5 (Procedure A) to Step 6 (Procedure B).

[0086] Also, in Operation Example 1-2 or Operation Example 1-3, before Step 4, the size of the new DCI format may be aligned with the size of the USS's DCI format 0_0 / 1_0. Moreover, when transitioning to Step 4, the size of the new DCI format is also aligned with the size of the new DCI format of the CSS. For example, if the new DCI format is smaller than the size of the CSS's DCI format 0_0 / 1_0, the size of the new DCI format is adjusted to the same size as the CSS's DCI format 0_0 / 1_0 by adding bits to the new DCI format. The added bits may be assumed to be zero padding or other known bits (columns). If the new DCI format is larger than the size of the CSS's DCI format 0_0 / 1_0, for example, the specified bits such as the frequency allocation bits of the new DCI format may be deleted to adjust the new DCI format for the CSS to the size of the CSS's DCI format 0_0 / 1_0. This operation of deleting the bits is also called "truncation" as described above.

[0087] (Configuration of Wireless Communication System) A wireless communication system according to one aspect of the present disclosure includes, for example, a base station 100 (e.g., gNB) shown in FIGS. 4 and 6 and a terminal 200 (e.g., UE) shown in FIGS. 5 and 7.

[0088] In the base station 100 shown in FIG. 4, the control unit 112 determines the DCI format and adjusts the size of the DCI format according to, for example, Operation Example 1-1, Operation Example 1-2, or Operation Example 1-3, and generates DCI addressed to the terminal 200.

[0089] The transmission unit 107 transmits the DCI generated by the control unit 112 to the terminal 200.

[0090] On one hand, in the terminal 200 shown in FIG. 5, the receiving unit 201 receives the DL signal transmitted by the base station 100.

[0091] The control unit 212 extracts, for example, the upper layer signal from the received DL signal, and based on the information of the DCI format indicated by the upper layer signal, performs the setting of the DCI format to be received and the size adjustment of the DCI format according to the setting.

[0092] (Configuration of the base station 100) The base station 100 shown in FIG. 6 includes, for example, a DCI format determination unit 101, a DCI format size adjustment unit 102, and a DCI generation unit 103. The DCI format determination unit 101, the DCI format size adjustment unit 102, and the DCI generation unit 103 may be regarded as an example of the control unit 112 shown in FIG. 4. Further, the base station 100 shown in FIG. 6 includes, for example, an error correction encoding unit 104, a modulation unit 105, a signal allocation unit 106, a transmission unit 107, a receiving unit 108, a signal separation unit 109, a demodulation unit 110, and an error correction decoding unit 111.

[0093] The error correction encoding unit 104, the modulation unit 105, the signal allocation unit 106, and the transmission unit 107 may be regarded as an example of a transmission processing unit that performs DL transmission processing. The receiving unit 108, the signal separation unit 109, the demodulation unit 110, and the error correction decoding unit 111 may be regarded as an example of a receiving processing unit that performs UL receiving processing.

[0094] The DCI format determination unit 101 determines, for example, the DCI format used by the base station 100 for each cell (for example, SpCell and SCell) for the terminal 200. Note that "SpCell" is an abbreviation of "special cell", and "SCell" is an abbreviation of secondary cell. "SpCell" is, for example, a primary cell (PCell) or a primary secondary cell (PSCell).

[0095] The information on the DCI format determined by the DCI format determination unit 101 for each cell is output to, for example, the error correction encoding unit 104 and the DCI format size adjustment unit 102. Note that the information on the DCI format output to the error correction encoding unit 104 may be regarded as an example of the information notified to the terminal 200 by the signaling of the upper layer.

[0096] The DCI format size adjustment unit 102 determines, for example, which DCI format the terminal 200 monitors for each cell based on the information on the DCI format (hereinafter also referred to as "setting information") input from the DCI format determination unit 101. The setting information on the DCI format may include, for example, in the case of the SpCell, setting information such as "monitor DCI format 0_0 / 1_0 in the CSS".

[0097] Based on the setting information on the DCI format, the DCI format size adjustment unit 102 determines whether to adjust the size of the DCI format as shown in Operation Example 1-1, Operation Example 1-2, or Operation Example 1-3, and adjusts the size of the DCI format according to the determination result. The information on the DCI format after size adjustment is output to, for example, the DCI generation unit 103.

[0098] Based on the information on the DCI format input from the DCI format size adjustment unit 102, the DCI generation unit 103 generates, for example, a DCI which is a control signal for allocating DL data and a DCI which is a control signal for allocating UL data.

[0099] The generated DCI is output to the signal allocation unit 106 as an example of the transmission data. For example, the DCI for allocating DL data is output to the signal allocation unit 106. The DCI for allocating UL data is output not only to the signal allocation unit 106 but also to the signal separation unit 109 as an example of a control signal indicating the position where the UL data is allocated.

[0100] The error correction encoding unit 104 takes, for example, a transmission data signal (DL data signal) and upper layer signaling as inputs, performs error correction encoding on the input signals, and outputs them to the modulation unit 105.

[0101] The modulation unit 105 performs modulation processing on the signals input from the error correction encoding unit 104, for example, and outputs the modulated data signals to the signal allocation unit 106.

[0102] The signal allocation unit 106 allocates, for example, a DL data signal and a DCI, which is an example of a control signal input from the DCI generation unit 103, to radio resources to form a transmission signal. The formed transmission signal is output to the transmission unit 107.

[0103] The transmission unit 107 performs radio transmission processing such as up-conversion and amplification on the input signals from the signal allocation unit 106, for example, to generate radio signals and transmits the radio signals from the antenna.

[0104] The reception unit 108 receives, for example, UL radio signals transmitted from the terminal 200 by the antenna, performs radio reception processing such as amplification and down-conversion on the received radio signals, and outputs them to the signal separation unit 109.

[0105] The signal separation unit 109 separates (or extracts), for example, the received signals (e.g., UL data signals) allocated to the UL radio resources based on the UL resource allocation information input from the DCI generation unit 103. The separated UL data signals are output to the demodulation unit 110.

[0106] The demodulation unit 110 performs demodulation processing on the input signals from the signal separation unit 109, for example, and outputs the demodulated signals to the error correction decoding unit 111.

[0107] The error correction decoding unit 111 decodes the input signals from the demodulation unit 110, for example, and outputs the UL received data signals from the terminal 200.

[0108] (Configuration of Terminal 200) The terminal 200 shown in FIG. 7 includes, for example, a receiving unit 201, a signal separating unit 202, a DCI receiving unit 203, a demodulating unit 204, and an error correction decoding unit 205. Further, the terminal 200 includes, for example, a DCI format setting receiving unit 206, a DCI format size adjusting unit 207, an error correction encoding unit 208, a modulating unit 209, a signal allocating unit 210, and a transmitting unit 211.

[0109] The receiving unit 201, the signal separating unit 202, the DCI receiving unit 203, the demodulating unit 204, and the error correction decoding unit 205 may be regarded as an example of a receiving processing unit that performs DL reception processing. The DCI format setting receiving unit 206 and the DCI format size adjusting unit 207 may be regarded as an example of the control unit 212 illustrated in FIG. 5. The error correction encoding unit 208, the modulating unit 209, the signal allocating unit 210, and the transmitting unit 211 may be regarded as an example of a transmitting processing unit that performs UL transmission processing.

[0110] The receiving unit 201 receives, for example, a DL reception signal by an antenna, performs radio reception processing such as amplification and down-conversion on the reception signal, and then outputs the reception signal to the signal separating unit 202.

[0111] The signal separating unit 202 separates, for example, a signal assigned to a PDCCH candidate position in the reception signal input from the receiving unit 201 and outputs the signal to the DCI receiving unit 203. Further, the signal separating unit 202 separates, for example, a DL data signal from the reception signal based on the DL resource allocation information input from the DCI receiving unit 203 and outputs the signal to the demodulating unit 204.

[0112] The DCI receiving unit 203 detects DCI in the output of the signal separating unit 202 based on information (for example, type and / or size) regarding the DCI format input from the DCI format size adjusting unit 207. Further, the DCI receiving unit 203 decodes and receives the detected DCI.

[0113] The decoded DCI information is selectively output to, for example, the signal separation unit 202 and the signal allocation unit 210. For example, in the decoded DCI information, the DL resource allocation information is output to the signal separation unit 202, and the UL resource allocation information is output to the signal allocation unit 210.

[0114] The demodulation unit 204 performs demodulation processing on the input signal from the signal separation unit 202, for example, and outputs the demodulated signal to the error correction decoding unit 205.

[0115] The error correction decoding unit 205 decodes the demodulated signal input from the demodulation unit 204, for example, and outputs the received data signal. Here, the signaling of the upper layer is output to the DCI format setting reception unit 206, for example.

[0116] The DCI format setting reception unit 206 sets the DCI format to be used for each cell based on the upper layer signaling input from the error correction decoding unit 205, for example, and outputs the setting information to the DCI format size adjustment unit 207.

[0117] The DCI format size adjustment unit 207 determines which DCI format to monitor for each cell, similar to the base station 100, based on the DCI format setting information input from the DCI format setting reception unit 206. When the cell is a SpCell, the DCI format setting information may include, for example, a setting to monitor DCI format 0_0 / 1_0 in the CSS.

[0118] Also, after determining the DCI format to be monitored, the DCI format size adjustment unit 207 determines whether to adjust the size of the DCI format as shown in Operation Example 1-1, Operation Example 1-2, or Operation Example 1-3, for example, and adjusts the size of the DCI format according to the determination result. The information of the DCI format after size adjustment is output to the DCI reception unit 203.

[0119] The error correction encoding unit 208 takes, for example, the UL transmission data signal as an input, performs error correction encoding on the input transmission data signal, and outputs the encoded signal to the modulation unit 209.

[0120] The modulation unit 209 modulates the signal input from the error correction encoding unit 208 and outputs the modulated signal to the signal allocation unit 210.

[0121] The signal allocation unit 210 identifies, for example, the radio resources to be allocated to the UL data signal based on the UL resource allocation information that is an input from the DCI reception unit 203, and allocates the UL data signal to the identified radio resources.

[0122] The transmission unit 211 performs radio transmission processing such as up-conversion and amplification on the input signal from the signal allocation unit 210 to generate a radio signal, and transmits the radio signal from the antenna.

[0123] (Supplementary matters of Embodiment 1) Regarding which of the above-described operation examples 1-1, 1-2, and 1-3 are to be used (or applied) in the base station 100 and the terminal 200, it may be determined in advance, or it may be selected according to the operation conditions. Also, which of the operation examples 1-1 to 1-3 is to be used may be determined by upper layer signaling.

[0124] Also, in Embodiment 1, it is assumed that the new DCI format is masked by an RNTI different from the C-RNTI, but it may be masked by the C-RNTI. In that case, information (for example, identification bits) for distinguishing between the existing DCI format and the new DCI format may be added to one or both of the individual DCI formats. Even if the sizes of the existing DCI format and the new DCI format are the same, the two can be identified or distinguished by the identification bits.

[0125] Also, when the new DCI format is masked by the C-RNTI, the "Procedure A" in Operation Example 1-1 and Operation Example 1-2 (Figure 2) may be set as the same determination condition as Step 3, with the addition of the total number limit (Condition B) for different sizes related to the C-RNTI.

[0126] In addition, in Operation Example 1-1, Operation Example 1-2, and Operation Example 1-3, the values X1 and X2 regarding the total number of different DCI format sizes may be determined by the upper layer settings or may be predetermined values.

[0127] In Embodiment 1, as an example of the new DCI format, a DCI format extended for URLLC was assumed. However, a DCI format extended for other purposes or applications may also fall under "new DCI format". Non-limiting examples of DCI formats extended for other purposes or applications include DCI formats for unlicensed bands, MTC (machine type communication), NB-IoT (narrow band-internet of things), V2X (vehicle-to-everything), MIMO (multiple-input and multiple-output), and the like.

[0128] In Operation Example 1-1 and Operation Example 1-2, in Step 3, it was assumed that when both of the following two Conditions A and B are satisfied, the process proceeds in the "YES" direction, and when either one of Conditions A and B is not satisfied, the process proceeds in the "NO" (Step 4) direction. (Condition A) The total number of different DCI format sizes is not greater than X1 (Condition B) The total number of different DCI format sizes monitored using the C-RNTI is not greater than X2

[0129] However, the same applies when Conditions A and B are replaced with, for example, the following Conditions A1 and B1, respectively. (Condition A1) The total number of different DCI format sizes is X1 or less. (Condition B1) The total number of different DCI format sizes monitored using C-RNTI is X2 or less.

[0130] Also, replace Condition A and Condition B with Condition A2 and B2 below respectively. When at least one of Condition A2 and B2 is satisfied, proceed to Step 4. If neither Condition A2 nor B2 is satisfied, it may be possible to proceed in another direction. (Condition A2) The total number of different DCI format sizes is greater than X1. (Condition B2) The total number of different DCI format sizes monitored using C-RNTI is greater than X2.

[0131] In "Procedure A", when Condition A "The total number of different DCI format sizes is not greater than X1" is satisfied, proceed in the "YES" direction. When it is not satisfied, proceed in the "NO" (Procedure B) direction. However, the same operation is possible even if Condition A is replaced with Condition A1 "The total number of different DCI format sizes is X1 or less".

[0132] In "Procedure A", when Condition A2 "The total number of different DCI format sizes is greater than X1" is satisfied, proceed in the direction of "Procedure B". When it is not satisfied, it may be possible to proceed in another direction.

[0133] (Embodiment 2) In Embodiment 2, an example of "Procedure B" in Embodiment 1 will be described. In Procedure B, the sizes between the new DCI format and other DCI format(s) are made equal. As a result, Condition A "The total number of different DCI format sizes is not greater than X1" will be satisfied.

[0134] Also, in Embodiment 2, it is assumed that the following relationship holds for the sizes between DCI formats. size of DCI format 0_0 / 1_0 in CSS <= size of DCI format 0_0 / 1_0 in USS <= size of DCI format 0_1 and 1_1 in USS

[0135] Also, when both the new DCI format for DL grant and the new DCI format for UL grant are set, the following settings shown in (1) to (3) are assumed.

[0136] (1) The new DCI format for DL grant and the new DCI format for UL grant are set to the same size. By doing so, it is possible to suppress the sizes of different DCI formats that increase due to the addition of the new DCI format.

[0137] (2) The new DCI format for DL grant and the new DCI format for UL grant can be set to different sizes, but before processing Procedure B, both are adjusted to the same size. By making the new DCI format and the DCI format for UL grant the same size before processing Procedure B, if the condition A that "the total number of different DCI format sizes is not greater than X1" is satisfied, Procedure B is skipped. In this way, when there is room for different DCI format sizes, different DCI format sizes can be set for DL assignment and UL grant, so for example, padding bits can be reduced.

[0138] (3) The new DCI format for DL grant and the new DCI format for UL grant can be set to different sizes, and Procedure B is performed for either one of the new DCI formats for DL grant and UL grant. When condition A "the total number of different DCI format sizes is not greater than X1" is satisfied, Procedure B for the other new DCI format is skipped. When condition A "the total number of different DCI format sizes is not greater than X1" is not satisfied, Procedure B is performed for the other new DCI format. Whether Procedure B is performed (or applied) first for the new DCI format for DL grant or UL grant may be predetermined, or it may be specified to perform it for the smaller size or the larger size. In this way, if condition A "the total number of different DCI format sizes is not greater than X1" can be satisfied in the size adjustment of either one of the new DCI formats, the other new DCI format can maintain the set size.

[0139] Also, a setting may be made to monitor both the new DCI format for USS and the new DCI format for CSS, and it is also conceivable that their sizes are different. In that case, assuming the settings shown in (1) to (3) below, similar to the case where the sizes are different between DL assignment and UL grant.

[0140] (1) The new DCI format for CSS and the new DCI format for USS shall be the same size as each other. In this way, it is possible to suppress the sizes of different DCI formats that increase due to the addition of the new DCI format.

[0141] (2) The new DCI format for CSS and the new DCI format for USS can be set to different sizes, but they are adjusted to the same size before the processing of Procedure B. By adjusting the new DCI formats for CSS and USS to the same size before the processing of Procedure B, if Condition A "the total number of different DCI format sizes is not greater than X1" is satisfied, Procedure B is skipped. In this way, when there is room for different DCI format sizes, the new DCI format for CSS and the new DCI format for USS can be set to different sizes, so that padding bits can be reduced.

[0142] (3) The new DCI format for CSS and the new DCI format for USS can be set to different sizes, and Procedure B is performed for either the new DCI format for CSS or the new DCI format for USS. If Condition A "the total number of different DCI format sizes is not greater than X1" is satisfied, Procedure B for the other new DCI format is skipped. If Condition A "the total number of different DCI format sizes is not greater than X1" is not satisfied, Procedure B is performed for the other new DCI format. Whether Procedure B is performed (or applied) first to the new DCI format for CSS or the new DCI format for USS may be predetermined, or it may be specified to perform it for the new DCI format with a smaller size or a larger size. In this way, if Condition A "the total number of different DCI format sizes is not greater than X1" can be satisfied in the size adjustment of either one of the new DCI formats, the other new DCI format can maintain the set size.

[0143] Fig. 8 shows an operation example according to Embodiment 2 in a flowchart.

[0144] In Procedure B-0, it is determined whether the size of the new DCI format is less than or equal to the size of the USS's DCI format 0_0 / 1_0. If the size of the new DCI format is less than or equal to the size of the USS's DCI format 0_0 / 1_0 (YES), the process proceeds to Procedure B-1. If it is larger than the size of the USS's DCI format 0_0 / 1_0 (NO), the process proceeds to Procedure B-2.

[0145] In Procedure B-1, the size of the new DCI format is adjusted to match the size of DCI format 0_0 / 1_0. An example of this will be described in Operation Example 2-1 below.

[0146] In Procedure B-2, it is determined whether the size of the new DCI format is less than or equal to the size of the USS's DCI format 0_1 / 1_1. If the size of the new DCI format is less than or equal to the size of the USS's DCI format 0_1 / 1_1 (YES), the process proceeds to Procedure B-3. If it is larger than the size of the USS's DCI format 0_1 / 1_1 (NO), the process proceeds to B-4.

[0147] In Procedure B-3, the size of the new DCI format is adjusted to match the size of DCI format 0_1 / 1_1. An example of this will be described in Operation Example 2-2 below.

[0148] In Procedure B-4, the size of DCI format 0_1 or DCI format 1_1 is adjusted to match the size of the new DCI format. An example of this will be described in Operation Example 2-3 below.

[0149] According to the operation shown in FIG. 8, when the size of the new DCI format is smaller than the sizes of other DCI format(s), among the other DCI format(s), the size is adjusted to the DCI format that is larger than the size of the new DCI format but has a smaller size among them. Therefore, the number of padding bits can be reduced.

[0150] Also, even when the size of the new DCI format is larger than the sizes of other DCI format(s), the size can be aligned with the other DCI format(s) by Procedure B-4. Therefore, the restrictions on the number of set bits of the new DCI format can be reduced (in other words, relaxed).

[0151] Note that the above-mentioned Procedure B-4 may be replaced by the following Procedure B-5 as illustrated in FIG. 9. Procedure B-5: To align the size of the new DCI format with the sizes of other DCI format(s), some of the set bits of the new DCI format are deleted. An example thereof will be described in Operation Example 2-4 below.

[0152] (Operation Example 2-1) In Operation Example 2-1, an example of Procedure B-1 shown in FIGS. 8 and 9 will be described. As a non-limiting example of Operation Example 2-1, three operation examples 2-1-1 to 2-1-3 can be cited. Which of the operation examples 2-1-1 to 2-1-3 to apply may be determined in advance or may be determined by signaling from a higher layer.

[0153] (Operation Example 2-1-1) Operation Example 2-1-1 can be applied to Step 2.3 (Procedure B) of Operation Example 1-2 and Step 2.3 (Procedure B) of Operation Example 1-3 in Embodiment 1.

[0154] In operation example 2-1-1, assume that the CSS DCI format_0_0 / 1_0 and the USS DCI format_0_0 / 1_0 have different sizes, and the size of the CSS DCI format_0_0 / 1_0 is smaller than that of the USS DCI format_0_0 / 1_0.

[0155] Fig. 10 shows the flowchart of operation example 2-1-1. In Procedure B-1-1, it is determined whether the size of the new DCI format is less than or equal to the size of the CSS DCI format_0_0 / 1_0. If the size of the new DCI format is less than or equal to the size of the CSS DCI format_0_0 / 1_0 (YES), the process proceeds to Procedure B-1-2. If the size of the new DCI format is larger than the size of the CSS DCI format_0_0 / 1_0 (NO), the process proceeds to Procedure B-1-3.

[0156] In Procedure B-1-2, by adding bits to the new DCI format, the size of the new DCI format is adjusted to the same size as the CSS DCI format0_0 / 1_0. The bits to be added may be assumed to be zero (zero padding), or other known bits (columns) may be assumed. By adding zero or known bits (columns), for example, the UE can use zero or known bits (columns) for error detection during DCI detection. Therefore, the reception error rate of DCI can be reduced.

[0157] In Procedure B-1-3, by adding bits to the new DCI format, the new DCI format is adjusted to the same size as the USS DCI format0_0 / 1_0. The bits to be added may be assumed to be zero (zero padding) as in Procedure B-1-2, or other known bits (columns) may be assumed.

[0158] In operation example 2-1-1, since the size of the new DCI format is adjusted to a DCI format with a smaller size, the number of bits added to the new DCI format can be reduced. Therefore, the reception quality of the new DCI format can be improved compared to other operation examples.

[0159] In addition, when the USS and the CSS overlap with each other, by aligning the size of the new DCI format set in the USS with the size of the DCI format of the CSS, the number of blind detections (BD) of the DCI in the UE can be reduced. For example, the number of BD of the DCI may be counted as 1 as long as the DCI formats have the same size even with different RNTIs. When the USS and the CSS do not overlap with each other, by aligning the size of the new DCI format set in the USS with the size of the DCI format of the CSS, the total number of different DCI format sizes can be reduced.

[0160] (Operation example 2-1-2) Operation example 2-1-2 can be applied to all Procedure Bs in operation examples 1-1, 1-2, and 1-3 in Embodiment 1. In operation example 2-1-2, Procedure B-1-3 shown in FIG. 10 is applied alone. In Procedure B-1-3, even if the new DCI format is set in the USS and a size smaller than the size of the DCI format 0_0 / 1_0 of the CSS is set, the size can be aligned with the DCI format 0_0 / 1_0 of the USS. Therefore, when the USS and the CSS overlap with each other, the number of BD detections by the UE can be reduced.

[0161] (Operation example 2-1-3) Operation example 2-1-3 can be applied to Step 2.3 (Procedure B) of operation example 1-2 and Step 2.3 (Procedure B) of operation example 1-3 in Embodiment 1.

[0162] In operation example 2-1-3, assume that the CSS DCI format_0_0 / 1_0 and the USS DCI format_0_0 / 1_0 have different sizes from each other, and that the size of the CSS DCI format_0_0 / 1_0 is smaller than that of the USS DCI format_0_0 / 1_0. Also assume that a new DCI format can be set for the CSS, and that the sizes of the new DCI format for the CSS and the new DCI format for the USS can be different from each other.

[0163] Fig. 11 shows a flowchart of operation example 2-1-3. In Procedure B-1-1’, it is determined whether the new DCI format is for the CSS and whether the size of the new DCI format for the CSS is less than or equal to the size of the CSS DCI format_0_0 / 1_0. If the new DCI format is for the CSS and the size of the new DCI format for the CSS is less than or equal to the size of the CSS DCI format_0_0 / 1_0 (YES), the process proceeds to Procedure B-1-2’. If the size of the new DCI format for the CSS is greater than the size of the CSS DCI format_0_0 / 1_0 (NO), the process proceeds to Procedure B-1-3. That is, even if it is the new DCI format for the CSS, if its size is larger than that of the CSS DCI format0_0 / 1_0, the process proceeds to Procedure B-1-3, and if the new DCI format is for the USS, the process proceeds to Procedure B-1-3 regardless of its size.

[0164] In Procedure B-1-2’, the new DCI format for the CSS is adjusted to the same size as the CSS DCI format0_0 / 1_0 by adding bits to the new DCI format for the CSS. The bits to be added may be zero padding, as in Procedure B-1-2, or other known bits (columns) may be assumed.

[0165] Procedure B-1-3 is the same as operation examples 2-1-1 and 2-1-2. For example, in Procedure B-1-3, by adding bits to the new DCI format, the new DCI format is adjusted to the same size as the DCI format0_0 / 1_0 of the USS. The added bits may be assumed to be zero padding, or other known bits (columns) may be assumed, similar to Procedure B-1-2.

[0166] According to operation example 2-1-3, when the sizes of the DCI format 0_0 / 1_0 for CSS and the DCI format 0_0 / 1_0 for USS are different from each other, the new DCI format for CSS can be adjusted to the size of the DCI format 0_0 / 1_0 for CSS, and the new DCI format for USS can be adjusted to the size of the DCI format 0_0 / 1_0 for USS. When the search spaces of the new DCI format and the DCI format 0_0 / 1_0 overlap in each of CSS and USS, the number of BD times by the UE can be reduced.

[0167] In operation example 2-1-3, in Procedure B-1-1’, the size of the new DCI format for CSS is compared with the size of the DCI format 0_0 / 1_0 for CSS. And when the size of the new DCI format for CSS is larger than the size of the DCI format 0_0 / 1_0 for CSS, the new DCI format for CSS is adjusted to the size of the DCI format 0_0 / 1_0 for USS. However, regardless of its size, the new DCI format for CSS may also be adjusted to the size of the DCI format 0_1 / 1_0 for CSS.

[0168] Also, when the size of the new DCI format for CSS is larger than that of the DCI format 0_0 / 1_0 for CSS, for example, for the frequency allocation bits of the new DCI format, etc., the specified bits may be deleted to adjust the size of the new DCI format for CSS to that of the DCI format 0_0 / 1_0 of CSS. The operation of deleting these bits is also called "truncation" as described above.

[0169] Also, when the size of the new DCI format for CSS is larger than that of the DCI format 0_0 / 1_0 for CSS, the detection of the new DCI format for CSS may be stopped.

[0170] In the method by bit deletion and DCI detection stop, the size of the DCI format 0_0 / 1_0 of CSS is not changed. Therefore, for example, even during a period when the UE does not detect (or cannot read) the DCI format for USS due to resetting of the upper layer, etc., the UE can continue communication using the DCI format 0_0 / 1_0 of CSS.

[0171] Note that in Operation Example 2-1, the relationship of size of DCI format 0_0 / 1_0 in CSS <= size of DCI format 0_0 / 1_0 in USS <= size of DCI format 0_1 and 1_1 in USS was assumed, but the size relationship of each DCI format is not limited to this assumption.

[0172] For example, the relationship of size of new DCI format < size of DCI format 0_1 and 1_1 in USS < size of DCI format 0_0 and 1_0 in USS may be assumed. In this case, in Procedure B3, the new DCI format may be adjusted to the size of the DCI format 0_1 and 1_1 in USS.

[0173] (Operation Example 2-2) In Operation Example 2-2, an example of Procedure B-3 shown in FIGS. 8 and 9 will be described. As a non-limiting example of Operation Example 2-2, five operation examples 2-2-1 to 2-2-5 can be cited. Which of operation examples 2-2-1 to 2-2-5 is to be applied may be determined in advance or may be determined by signaling from a higher layer.

[0174] (Operation Example 2-2-1) In Operation Example 2-2-1, the new DCI format for DL assignment or the new DCI format for UL grant is made larger than the new DCI format and is sized to be the smaller of DCI format 0_1 (for UL grant) and DCI format 1_1 (for DL assignment).

[0175] Therefore, size adjustment is performed for both the new DCI format for DL assignment and the new DCI format for UL grant. When the size of the new DCI format is smaller than the smaller of DCI format 0_1 and DCI format 1_1, the new DCI formats for DL assignment and UL grant have the same size as each other.

[0176] According to Operation Example 2-2-1, since the new DCI format is sized to the smaller DCI format 0_1 or DCI format 1_1, padding bits can be reduced.

[0177] (Operation Example 2-2-2) In operation example 2-2-2, the new DCI format for DL assignment is sized to DCI format 1_1 (DL assignment), and the new DCI format for UL grant is sized to DCI format 0_1 (for UL grant). If DCI format 1_1 or DCI format 0_1 is not set, the new DCI format may also be sized to the set DCI format.

[0178] According to operation example 2-2-2, the sizes of DL control signals can be matched with each other, and the sizes of UL control signals can be matched with each other. Therefore, for example, even when the UL BWP is changed, the DL control signal can continue to be used without being affected by the size change. In other words, the UE can continue blind detection for the DL control signal.

[0179] (Operation example 2-2-3) In operation example 2-2-3, both new DCI formats for DL assignment and UL grant are sized to DCI format 1_1. If DCI format 1_1 is not set, and if the size of the new DCI format is larger than the size of DCI format 1_1 and less than or equal to the size of DCI format 0_1, the new DCI formats for DL assignment and UL grant may be sized to DCI format 0_1.

[0180] According to operation example 2-2-3, even when the UL BWP is changed, size change may not be necessary when the new DCI format for UL grant is sized to DCI format 1_1.

[0181] (Operation example 2-2-4) In operation example 2-2-4, the new DCI format for DL assignment is sized to match DCI format 0_1 (for UL grant), and the new DCI format for UL grant is sized to match DCI format 1_1 (for DL assignment). If DCI format 1_1 or DCI format 0_1 is not set, the new DCI format DCI may be adjusted to match the set DCI format.

[0182] According to operation example 2-2-4, the sizes of the DL control signal and the UL control signal are matched. When the sizes of the DL control signal and the UL control signal are close (for example, when the size difference is below a threshold), the number of padding bits may be reduced.

[0183] (Operation example 2-2-5) In operation example 2-2-5, both new DCI formats for DL assignment and UL grant are sized to match DCI format 0_1. If DCI format 0_1 is not set, and if the size of the new DCI format is larger than the size of DCI format 0_1 and less than or equal to the size of DCI format 1_1, the new DCI format DCI for DL assignment and UL grant may be sized to match format 1_1.

[0184] According to operation example 2-2-5, when the DL BWP is changed, it may not be necessary to perform a size change when the new DCI format for UL grant is sized to match DCI format 0_1.

[0185] (Operation example 2-3) In Operation Example 2-3, an example of Procedure B-4 shown in FIG. 8 will be described. As a non-limiting example of Operation Example 2-3, five operation examples 2-3-1 to 2-3-5 can be cited. Which of the operation examples 2-3-1 to 2-3-5 is to be applied may be determined in advance or may be determined by signaling from a higher layer.

[0186] (Operation Example 2-3-1) In Operation Example 2-3-1, DCI format 0_1 (for UL grant) or DCI format 1_1 (for DL assignment) is made larger than DCI format 0_1 (for UL grant) or DCI format 1_1 (for DL assignment), and the size is adjusted to the smaller one of DCI format 0_1 (for UL grant) and DCI format 1_1 (for DL assignment).

[0187] Therefore, size adjustment is performed for both DCI format 1_1 and DCI format 0_1. When the size of the smaller new DCI format is even smaller, DCI format 1_1 and DCI format 0_1 will have the same size.

[0188] According to Operation Example 2-3-1, since the size of DCI format 0_1 (for UL grant) or DCI format 1_1 (for DL assignment) is adjusted to the smaller new DCI format, padding bits can be reduced.

[0189] (Operation Example 2-3-2) In operation example 2-3-2, the new DCI format for DL assignment is sized to match DCI format 1_1 (for DL assignment), and the new DCI format for UL grant is sized to match DCI format 0_1 (for UL grant). If DCI format 1_1 or DCI format 0_1 is not configured, the new DCI format may be sized to match the configured DCI format.

[0190] According to operation example 2-3-2, since the sizes of DL control signals are matched with each other and the sizes of UL control signals are matched with each other, even when the UL BWP is changed, the DL control signals can be continuously used without being affected by the size change. In other words, the UE can continue blind detection for DL control signals.

[0191] (Operation example 2-3-3) In operation example 2-3-3, both DCI format 1_1 and DCI format 0_1 are sized to match the new DCI format for DL assignment. If the new DCI format for DL assignment is not configured, and if the size of DCI format 1_1 or DCI format 0_1 is larger than the size of the new DCI format for DL assignment and less than or equal to the size of the DCI format for UL grant, DCI format 1_1 and DCI format 0_1 may be sized to match the new DCI format for UL grant.

[0192] According to operation example 2-3-3, even when there is a change in the UL BWP, it may not be necessary to perform a size change when the size of DCI format 0_1 is already matched to the size of the DCI for DL assignment.

[0193] (Operation example 2-3-4) In operation example 2-3-4, the new DCI format for DL assignment is sized to match DCI format 0_1 (for UL grant), and the new DCI format for UL grant is sized to match DCI format 1_1 (for DL assignment). If DCI format 1_1 or DCI format 0_1 is not configured, the new DCI format may be sized to match the configured DCI format.

[0194] According to operation example 2-3-4, the sizes of the DL control signal and the UL control signal are matched. When the sizes of the control signal for DL and the control signal for UL are close (for example, when the difference in size is below a threshold), the number of padding bits may be reduced.

[0195] (Operation example 2-3-5) In operation example 2-3-3, both DCI format 1_1 and DCI format 0_1 are sized to match the new DCI format for UL grant. If the new DCI format for UL grant is not configured, and if the sizes of DCI format 1_1 or DCI format 0_1 are larger than the size of the new DCI format for UL grant and less than or equal to the size of the DCI format for DL assignment, DCI format 1_1 and DCI format 0_1 may be sized to match the new DCI format for DL assignment.

[0196] According to operation example 2-3-5, even when there is a change in the DL BWP, it may not be necessary to perform a size change when the size of DCI format 0_1 is already matched to the size of the DCI for UL grant.

[0197] (Operation example 2-4) In Operation Example 2-4, an example of Procedure B-5 shown in FIG. 9 will be described. As a non-limiting example of Operation Example 2-4, five operation examples 2-4-1 to 2-4-5 can be cited. Which of operation examples 2-4-1 to 2-4-5 is to be applied may be determined in advance or may be determined by signaling from a higher layer.

[0198] (Operation Example 2-4-1) In Operation Example 2-4-1, among DCI format 0_0 / 1_0 for CSS, DCI format 0_0 / 1_0 for USS, DCI format 0_1, and DCI format 1_1, the size of the new DCI format is adjusted to match that of the DCI format with the largest size. Therefore, in Operation Example 2-4-1, the new DCI format is made the same size as the specified DCI format by deleting the specified bits in the field of the new DCI format (truncation).

[0199] As an example of the bits for which deletion is specified, bits for resource allocation in the frequency direction can be cited. According to Operation Example 2-4-1, since the size of the new DCI format is adjusted to match that of the larger-sized DCI format, the number of bits to be deleted can be reduced.

[0200] (Operation Example 2-4-2) In Operation Example 2-4-2, the new DCI format for DL assignment is made the same size as DCI format 1_1 (for DL assignment), and the new DCI format for UL grant is made the same size as DCI format 0_1 (for UL grant). If DCI format 1_1 or DCI format 0_1 is not set, the new DCI format may be made the same size as the set DCI format. For example, the size of the new DCI format is adjusted by deleting the specified bits in the field of the new DCI format.

[0201] According to Operation Example 2-4-2, since the sizes of DL control signals are adjusted among themselves and the sizes of UL control signals are adjusted among themselves, even when the UL BWP is changed, the DL control signals can be continuously used without undergoing size changes. In other words, the UE can continue blind detection for the DL control signals.

[0202] (Operation Example 2-4-3) In Operation Example 2-4-3, the sizes of both the new DCI formats for DL assignment and UL grant are adjusted to match the size of DCI format 1_1. When DCI format 1_1 is not configured, and when the size of the new DCI format is larger than the size of DCI format 1_1 and less than or equal to the size of DCI format 0_1, the new DCI format may be adjusted to match the size of DCI format 0_1. For example, the size of the new DCI format is adjusted by deleting specified bits in the field of the new DCI format.

[0203] According to Operation Example 2-4-3, even when there is a change in the UL BWP, size changes may not be performed when the new DCI format for UL grant is adjusted to the size of DCI format 1_1 if it is not necessary.

[0204] (Operation Example 2-4-4) In operation example 2-4-4, the new DCI format for DL assignment is sized to match DCI format 0_1 (for UL grant), and the new DCI format for UL grant is sized to match DCI format 1_1 (for DL assignment). If DCI format 1_1 or DCI format 0_1 is not configured, the new DCI format may be sized to match the configured DCI format. For example, the size of the new DCI format is adjusted by deleting specified bits in the fields of the new DCI format.

[0205] According to operation example 2-4-4, the sizes of the DL control signal and the UL control signal will be aligned. When the sizes of the control signal for DL and the control signal for UL are close (for example, when the difference in size is below a threshold), the number of padding bits may be reduced.

[0206] (Operation example 2-4-5) In operation example 2-4-5, both the new DCI formats for DL assignment and UL grant are sized to match DCI format 0_1. If DCI format 0_1 is not configured, and the size of the new DCI format is larger than the size of DCI format 0_1 and less than or equal to the size of DCI format 1_1, the new DCI format may be sized to match DCI format 1_1. For example, the size of the new DCI format is adjusted by deleting specified bits in the fields of the new DCI format.

[0207] According to operation example 2-4-5, even when there is a change in the DL BWP, the size change may not be necessary when the new DCI format for DL assignment is sized to match DCI format 0_1.

[0208] (Operation Example 2-5) In Operation Example 2-5, among the following DCI format(s), the ones with the closest sizes are adjusted to the same size. ·DCI format 0_0 / 1_0 ·DCI format 0_1 ·DCI format 1_1 ·New DCI format for UL grant ·New DCI format for DL assignment

[0209] In Step 2.3 (Procedure B) of Operation Example 1-2 and Step 2.3 (Procedure B) of Operation Example 1-3 in Embodiment 1, when the DCI format 0_0 / 1_0 of CSS is different from the DCI format 0_0 / 1_0 of USS, the sizes of the DCI format 0_0 / 1_0 of CSS and the DCI format 0_0 / 1_0 of USS may be distinguished, and the ones with close sizes may be adjusted to the same size.

[0210] When aligning the size to the DCI format 0_0 / 1_0 of CSS, the bits of other DCI formats are reduced to align with the DCI format 0_0 / 1_0 of CSS. In other combinations, to align the smaller DCI format with the larger DCI format, bits are added to the smaller DCI format.

[0211] According to Operation Example 2-5, the number of padding bits used for size adjustment and the number of bits to be deleted for size adjustment can be reduced.

[0212] (Operation Example 2-6) In Operation Example 2-6, information indicating which DCI format(s) to align the size of the new DCI format with is notified to the terminal 200 by signaling from the base station 100 to the upper layer, for example.

[0213] If the new DCI format is larger than the size of the specified DCI format with the same size, the following operations of the terminal 200 can be considered. · Do not detect the new DCI format as an error case. · Delete the specified bits such as the frequency allocation bits of the new DCI format to match the size of the specified DCI format with the same size (truncation). · Add bits to the specified DCI format with the same size to match the size of the new DCI format.

[0214] (Overall supplementary matters) When the new DCI format for DL assignment and the new DCI format for UL grant have the same size, bits (identification bits) for distinguishing between the two may be added to one or both of the new DCI formats for DL assignment and UL grant. Also, even when the new DCI format for DL assignment and the new DCI format for UL grant have different sizes, bits (identification bits) for distinguishing between the two may be added to one or both of the new DCI formats for DL assignment and UL grant in advance. If the identification bits are added in advance, even when size adjustment is not required, for example, identification by the identification bits becomes possible in relation to the DCI format assigned later.

[0215] Although the signal of PDCCH is given as an example of the control signal, each of the above-described embodiments may be applied to control signals with other names. For example, the above-described embodiments may be applied to signals of control channels with other names such as EPDCCH (enhanced PDCCH), R-PDCCH (relay-PDCCH), and MPDCCH (MTC PDCCH).

[0216] The PDCCH may be transmitted from the same carrier as the PDSCH, which is called self-carrier scheduling, or from a carrier different from the PDSCH, which is called cross-carrier scheduling.

[0217] A "carrier" may also be referred to as a "sub-carrier" or a "component carrier". For a UE, one or more BWPs may be configured within one carrier. Also, "carrier" may be read as "cell" or "BWP".

[0218] The term "condition" may be read as other terms such as "criterion", "rule", "specification", or "method". Also, the term "judgment" may be read as other terms such as, for example, "decision", "determination", "calculation", or "processing".

[0219] Also, the notation "··· part" used in the above embodiments may be replaced with other notations such as, for example, "··· circuitry", "··· device", "··· unit", or "··· module".

[0220] Also, the use of terms such as "first" and "second" used in this disclosure (including the claims and abstract) is for convenience in distinguishing between two or more elements to which the terms are attached, and does not limit the number (quantity) or order of each element. For example, a reference to the first and second elements does not mean that only two elements can be adopted, nor does it mean that the first element must precede the second element.

[0221] The present disclosure can be implemented by software, hardware, or software in cooperation with hardware. Each functional block used in the description of the above embodiments is realized, partially or wholly, as an LSI which is an integrated circuit, and each process described in the above embodiments may be controlled, partially or wholly, by one LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of one chip so as to include some or all of the functional blocks. The LSI may be provided with data input and output. Depending on the degree of integration, the LSI may also be referred to as an IC, a system LSI, a super LSI, or an ultra LSI.

[0222] Also, the method of integrating into an integrated circuit is not limited to LSI, and it may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. Further, after manufacturing the LSI, an FPGA (Field Programmable Gate Array) which can be programmed, or a reconfigurable processor capable of reconfiguring the connection and setting of circuit cells inside the LSI may be used. The present disclosure may be realized as digital processing or analog processing.

[0223] Furthermore, if an integrated circuit technology that replaces the LSI appears due to the progress of semiconductor technology or other derived technologies, naturally, the technology may be used to integrate the functional blocks. The application of biotechnology and the like may be possible.

[0224] The present disclosure can be implemented in any type of apparatus, device, system having a communication function (collectively referred to as a communication apparatus). Non-limiting examples of communication apparatuses include telephones (mobile phones, smartphones, etc.), tablets, personal computers (PCs) (laptops, desktops, notebooks, etc.), cameras (digital still / video cameras, etc.), digital players (digital audio / video players, etc.), wearable devices (wearable cameras, smartwatches, tracking devices, etc.), game consoles, digital book readers, telehealth / telemedicine (remote healthcare / medical prescription) devices, vehicles or mobile transportation means with a communication function (automobiles, airplanes, ships, etc.), and combinations of the above various apparatuses.

[0225] The communication apparatus is not limited to portable or mobile ones, and includes any type of apparatus, device, system that is not portable or fixed, for example, smart home devices (home appliances, lighting devices, smart meters or measuring devices, control panels, etc.), vending machines, and any "Things" that can exist on other IoT (Internet of Things) networks.

[0226] Communication includes data communication by cellular systems, wireless LAN systems, communication satellite systems, etc., as well as data communication by combinations of these.

[0227] In addition, the communication apparatus also includes devices such as controllers and sensors that are connected or coupled to a communication device that executes the communication function described in the present disclosure. For example, it includes controllers and sensors that generate control signals and data signals used by the communication device that executes the communication function of the communication apparatus.

[0228] In addition, the communication apparatus includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, system that communicates with or controls the above various non-limiting apparatuses.

[0229] <Summary of the present disclosure> The base station according to the present disclosure includes a control circuit that sequentially performs a first process of aligning the size of control information between a first format for a first search space and a second format for a second search space, and a second process of aligning the size of the control information between a third format and the first format or the second format, and a transmission circuit that transmits the control information.

[0230] In the base station according to the present disclosure, the control circuit may perform the first process before the second process.

[0231] Also, in the base station according to the present disclosure, the control circuit may perform the second process before the first process.

[0232] Also, in the base station according to the present disclosure, after the first process, the control circuit determines whether or not it is satisfied that the total number of different sizes does not exceed a predetermined value, and if it is not satisfied that the total number of different sizes does not exceed the predetermined value, the control circuit may perform the second process.

[0233] Also, in the base station according to the present disclosure, before the second process, the control circuit determines whether or not it is satisfied that the total number of different sizes does not exceed a predetermined value, and if it is not satisfied that the total number of different sizes does not exceed the predetermined value, the control circuit performs the second process.

[0234] Also, in the base station according to the present disclosure, in the second process, the control circuit may align the control information to the size of the first format or the second format that is larger than the size of the third format.

[0235] Also, in the base station according to the present disclosure, in the second process, the control circuit may align the control information for downlink or uplink to a size larger than the size of the third format and smaller than the size of the first format or the second format for downlink and uplink.

[0236] The terminal according to the present disclosure includes a control circuit that controls reception of the control information based on information regarding application of a first process of aligning the size of control information between a first format and a second format, and a second process of aligning the size of the control information between a third format and the first format or the second format, and a reception circuit that receives the control information in response to the control.

[0237] The communication method for a base station according to the present disclosure performs a first process of aligning the size of control information between a first format for a first search space and a second format for a second search space, and a second process of aligning the size of the control information between a third format and the first format or the second format in stages, and transmits the control information.

[0238] The communication method for a terminal according to the present disclosure controls reception of the control information based on information regarding application of a first process of aligning the size of control information between a first format for a first search space and a second format for a second search space, and a second process of aligning the size of the control information between a third format and the first format or the second format, and receives the control information in response to the control.

Industrial Applicability

[0239] The present disclosure is suitable for, for example, a wireless communication system.

Description of Signs

[0240] 100 Base station 101 DCI format determination unit 102 DCI format size adjustment unit 103 DCI generation unit 104 Error correction coding unit 105 Modulation unit 106 Signal allocation unit 107 Transmission unit 108 Reception unit 109 Signal separation unit 110 Demodulation unit 111 Error correction decoding unit 200 Terminal 201 Reception unit 202 Signal separation unit 203 DCI reception unit 204 Demodulation unit 205 Error correction decoding unit 206 DCI format setting reception unit 207 DCI format size adjustment unit 208 Error correction coding unit 209 Modulation unit 210 Signal allocation unit 211 Transmission unit

Claims

【Claim 1】 A DCI format determination unit that sets a plurality of DCI formats including, in one or more signals, downlink control information (DCI) format 0_0, DCI format 1_0, a first new DCI format used for scheduling a physical uplink shared channel (PUSCH), and a second new DCI format used for scheduling a physical downlink shared channel (PDSCH), and a DCI format size adjustment unit that adjusts the one or more signals to a DCI format size, wherein the communication device, each of the first new DCI format and the second new DCI format is different from any of the following DCI formats, DCI format 0_0 DCI format 0_1 DCI format 1_0 DCI format 1_1 DCI format 2_0 DCI format 2_1 DCI format 2_2 padding or truncation is applied to the plurality of DCI formats based on a procedure including the following steps: (1) Determine the DCI format 0_0 and the DCI format 1_0, (2) Determine the first new DCI format and the second new DCI format, (3) Check a first condition that a first total number of different DCI sizes of the plurality of DCI formats is less than or equal to a first determined number, and a second condition that a second total number of different DCI sizes monitored using a cell-radio network temporary identifier (C-RNTI) of the plurality of DCI formats is less than or equal to a second determined number, (4) If both the first condition and the second condition are satisfied, end the procedure, (5) Adjust the sizes of the DCI format 0_0 and the DCI format 1_0, (6) Check the first condition and the second condition, (7) If both the first condition and the second condition are satisfied, end the procedure, (8) Adjust the size of the first new DCI format to one of the sizes of the plurality of DCI formats, Communication device. Claim 2 The method includes adjusting the size of the first new DCI format to the size of the second new DCI format. The communication device according to claim 1. Claim 3 The DCI format 0_0 and the DCI format 1_0 are monitored in a user equipment (UE) specific search space (USS). The communication device according to claim 1. Claim 4 The first new DCI format and the second new DCI format are monitored in the USS and not monitored in the common search space (CSS). The communication device according to claim 1. Claim 5 The first new DCI format and the second new DCI format are newly introduced earlier than any of the following DCI formats: DCI format 0_0, DCI format 0_1, DCI format 1_0, DCI format 1_1, DCI format 2_0, DCI format 2_1, DCI format 2_2 The communication device according to claim 1.

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