JP2024116780A - Terminal device, control method and program for efficiently transmitting uplink control information - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently transmit uplink control information.

SOLUTION: A terminal device is configured to: specify, in transmitting user data to a base station device using a first transport block and a second transport block in parallel, priority of uplink control information (UCI) to be transmitted with the user data; determine, based on the priority, which the first transport block or second transport block the UCI is to be multiplexed with the user data; and generate a first transport block and a second transport block by multiplexing the UCI with the user data in the transport block determined that the UCI is to be multiplexed, to be transmitted to the base station device.

SELECTED DRAWING: Figure 5

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a technique for controlling the transmission of uplink control information.

Standards such as the Long Term Evolution (LTE) and fifth generation (5G) standards of the Third Generation Partnership Project (3GPP (registered trademark)) stipulate that uplink control information (UCI) used to control communications is transmitted from a terminal device to a base station device. Such control information is transmitted via a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). Here, when UCI is transmitted via a PUSCH, the UCI is multiplexed with a transport block of the uplink shared channel (UL-SCH) and transmitted (see Non-Patent Document 1).

The PUSCH can be composed of multiple (two) transport blocks. That is, the terminal device can transmit two transport blocks in parallel. At this time, the UCI is transmitted in at least one of the two transport blocks. In LTE, the block channel quality indicator (CQI) and the precoding matrix index (PMI) are multiplexed in the transport block with the higher modulation and coding scheme (MCS) of the two transport blocks that compose the PUSCH. In addition, the HARQ-ACK and the rank indication (RI) are distributed and multiplexed in both of the two transport blocks.

3GPP (registered trademark) TS36.212, V17.1.0, March 2022

In 5G, it is expected that various communication services with different requirements will be provided, such as high-speed, large-capacity communication and ultra-reliable, low-latency communication (URLLC). Even if it becomes possible to configure a PUSCH with two or more transport blocks in 5G, if the UCI for each communication service is transmitted in the same manner as in LTE, it is expected that the requirements of the communication services will not be met.

The present invention provides a technique for efficient transmission of uplink control information.

A terminal device according to one aspect of the present invention has a determination means for determining a priority of uplink control information (UCI) to be transmitted together with user data when the user data is transmitted to a base station device using a first transport block and a second transport block in parallel, a determination means for determining, based on the priority, in which of the first transport block and the second transport block the UCI should be multiplexed with the user data, and a transmission means for multiplexing the user data and the UCI in the transport block in which it has been determined that the UCI should be multiplexed, thereby generating the first transport block and the second transport block and transmitting the generated blocks to the base station device.

The present invention makes it possible to transmit uplink control information efficiently.

FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication system. FIG. 2 illustrates an example of a hardware configuration of the apparatus. FIG. 2 is a diagram illustrating an example of a functional configuration of a terminal device. FIG. 2 is a diagram illustrating an example of a functional configuration of a base station device. 13 is an example of a processing flow when a terminal device independently determines a transport block into which UCI is multiplexed. 13 is a diagram illustrating an example of a processing flow when a base station device provides, to a terminal device, criterion information for determining a transport block into which UCI is multiplexed. This is an example of a processing flow when a base station device provides a terminal device with information specifying a transport block into which HARQ-ACK is multiplexed. 13 is an example of a processing flow when a base station device provides a terminal device with information specifying a transport block into which CSI is multiplexed.

The following embodiments are described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be combined in any combination. In addition, the same reference numbers are used for the same or similar configurations, and duplicate descriptions are omitted.

(System Configuration)
FIG. 1 shows an example of the configuration of a wireless communication system according to this embodiment. The wireless communication system is, for example, a fifth generation (5G) cellular communication system, and includes a terminal device 101 and a base station device 102. A plurality of streams (not shown) can be configured between the terminal device 101 and the base station device 102 using a plurality of antennas. In addition, the terminal device 101 and the base station device 102 can communicate a plurality of (for example, two) transport blocks of an uplink shared channel (UL-SCH) in parallel using the plurality of streams. In the following, for simplicity of explanation, it is assumed that a maximum of two transport blocks are communicated in parallel, but the following discussion can also be applied to the case where three or more transport blocks are communicated in parallel. FIG. 1 shows an example in which the terminal device 101 generates and transmits two transport blocks 111 and 112 for transmitting user data. Note that these transport blocks are mapped to a physical uplink control channel (PUSCH) and transmitted to the base station device 102 via a plurality of streams formed using a plurality of antennas.

The terminal device 101 transmits uplink control information (UCI) including an acknowledgment indicating the measurement result of the radio environment and the reception result of user data to the base station device 102 for communication control by the base station device 102. For example, the UCI is used when notifying the base station device 102 of channel state information (CSI) and an acknowledgment response (HARQ-ACK) of a composite automatic repeat request. The UCI is notified to the base station device 102 via a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). Here, when the UCI is transmitted via the PUSCH, the UCI is multiplexed with the user data in the transport block. Here, the terminal device 101 can transmit multiple transport blocks in parallel as described above. Therefore, the UCI is multiplexed into at least one of the multiple transport blocks and transmitted.

Here, in long-term evolution (LTE), the terminal device is configured to be able to transmit two transport blocks in parallel, and a channel quality indicator (CQI) and a precoding matrix index (PMI), which are part of the CSI, are multiplexed into the transport block that uses a modulation and coding scheme (MCS) with a higher communication rate (communication speed) among the two transport blocks. In addition, HARQ-ACK and rank indication (RI) included in the CSI are distributed and multiplexed into each of the two transport blocks. If such an LTE method is applied to 5G as it is, it is expected that the communication requirements cannot be met. In fact, in 5G, it is expected that various communication services such as high-speed large-capacity communication and ultra-reliable low-latency communication (URLLC) will be provided, and the requirements for communication of UCI may differ for each of these communication services. For example, for reliable communication, it is important that HARQ-ACK arrives reliably at the base station device 102. For this reason, even if an MCS with a low communication rate is used, for example, a situation may occur in which it is better to transmit UCI in a transport block with a low error rate. However, in the LTE method, for example, it is assumed that HARQ-ACK for reliable communication is multiplexed into a transport block with a high target error rate. In addition, the amount of information of CQI and PMI increases when information about multiple carriers is to be transmitted by carrier aggregation (CA) or the like. In addition, the amount of information of CQI and PMI may increase due to measurement settings, etc. In this case, for example, when the size of the transport block is small, the ratio of the amount of data of CQI and PMI to the amount of user data in the transport block increases, and the frequency utilization efficiency may decrease. That is, when the amount of data of UCI increases, it is assumed that UCI is better multiplexed into a transport block with a larger size, for example. On the other hand, in the above-mentioned LTE method, it is not possible to select a transport block into which such UCI should be multiplexed, and the efficiency of communication may decrease.

In view of these circumstances, this embodiment provides a method for multiplexing UCI into an appropriate transport block when multiple transport blocks are transmitted in parallel.

In one example, the terminal device 101 may determine which of a plurality of transport blocks to multiplex the UCI into based on the priority of the UCI. The priority of the UCI is specified, for example, based on the priority index of the UCI. In one example, a high priority (e.g., priority index = 1) is assigned to a UCI that requires high reliability. A low priority (e.g., priority index = 0) is assigned to a UCI that may be relatively unreliable. For example, the priority of the HARQ-ACK transmitted in the uplink is determined based on the priority of the downlink data that is the target of the acknowledgement. For example, the downlink control information (DCI) transmitted when transmitting the physical downlink shared channel (PDSCH) includes a priority indicator. The priority of the PDSCH and the corresponding HARQ-ACK can be dynamically determined based on the value of this priority indicator. That is, when a DCI with a priority indicator value set to "1" is transmitted, the PDSCH and HARQ-ACK corresponding to the DCI are treated as having a high priority. Also, when a DCI with a priority indicator value set to "0" is transmitted, the PDSCH and HARQ-ACK corresponding to the DCI are treated as having a low priority. In this way, different priorities can be assigned to the HARQ-ACK depending on the priority of the corresponding PDSCH. For this reason, in this embodiment, the terminal device 101 can determine the priority of each HARQ-ACK and determine which transport block to multiplex according to the determined priority. Also, when a non-periodic CSI is reported, the CSI is classified into two parts according to the standard, which should be reported as CSI. That is, the first part includes RI, CSI-RS resource indicator, and CQI for the first codeword, and the second part includes PMI, layer indicator, and CQI for the second codeword. Then, the terminal device 101 of the present embodiment can determine a transport block in which the first part is high-priority information and the second part is low-priority information and multiplexed. In addition, in the case of semi-persistent CSI reporting, for example, the priority may be determined based on the value of the priority indicator indicated in the DCI for enabling the reporting of the CSI. That is, when the value of the priority indicator is set to "1" and semi-persistent CSI reporting is enabled, the priority of the subsequent periodic CSI report is treated as being high. Note that the contents of the report at this time are determined in advance by the setting of the radio resource control (RRC) layer. In this case, the same priority can be assigned to all report contents. Conventionally, the transport block into which information such as CSI or HARQ-ACK is multiplexed is determined according to the type of information. In this manner, however, in this embodiment, information of the same type but with different priorities can be multiplexed into different transport blocks.

The terminal device 101 may, for example, multiplex high-priority UCI onto a transport block using an MCS corresponding to a relatively high communication rate. It is assumed that an MCS with a high communication rate is used when the wireless quality is relatively good. For this reason, by multiplexing high-priority UCI onto a transport block of an MCS corresponding to a relatively high communication rate, it is possible to transmit the UCI by highly reliable communication performed with such high wireless quality. In addition, for example, when a target error rate is set for each transport block, the terminal device 101 may multiplex high-priority UCI onto a transport block with a lower target error rate. For example, when a first transport block is used to carry URLLC traffic and a second transport block is used to carry traffic other than URLLC, such as enhanced mobile broadband (eMBB), it is assumed that the target error rate of the first transport block is lower than the target error rate of the second transport block. For this reason, high-priority UCI can be multiplexed in the first transport block, and low-priority UCI can be multiplexed in the second transport block. This allows uplink transmission to be performed taking into account the priority of the UCI, making it possible to prevent a decrease in the error rate of high-priority UCI.

When the MCS and target error rate of the two transport blocks are the same, the high-priority UCI may be multiplexed in the transport block with the smaller transport block number. In addition, the low-priority UCI may also be multiplexed in the same transport block as the high-priority UCI, for example, when the total number of bits of the high-priority UCI and the low-priority UCI is equal to or less than a predetermined value. Here, the predetermined value may be calculated, for example, by multiplying the size of the transport block in which the high-priority UCI is multiplexed by a predetermined ratio. In other words, the low-priority UCI may also be multiplexed within a range that can ensure sufficient capacity to transmit user data in the transport block in which the high-priority UCI is multiplexed. This allows the terminal device 101 to transmit the high-priority UCI with high reliability or high efficiency, while improving the reliability and efficiency of the low-priority UCI.

Also, as described above, an example of a process for identifying a transport block into which a high-priority UCI should be multiplexed has been described according to the MCS used in each transport block and the target error rate for each transport block, but the present invention is not limited to this. For example, a high-priority UCI may be multiplexed into a transport block with high wireless quality according to the wireless quality of each transport block. In one example, the terminal device 101 retransmits a transport block when, for example, some of the multiple transport blocks are not normally received by the base station device 102. At this time, it is assumed that the terminal device 101 transmits the transport block using an MCS with a lower communication rate than other transport blocks even if the wireless quality is good, in order to ensure that the retransmission of the transport block is successful. In this case, the terminal device 101 may multiplex a high-priority UCI into a transport block with an MCS with a relatively low communication rate. That is, since it is assumed that the error rate is reduced by using an MCS with a relatively low communication rate, a UCI that requires high reliability may be transmitted in such a transport block with a low error rate. Furthermore, the terminal device 101 may, for example, identify an expected bit error rate based on a combination of wireless quality and MCS, and multiplex high-priority UCI into a transport block with a low bit error rate.

In this way, the terminal device 101 can independently determine which transport block the UCI to be transmitted should be multiplexed into, based on the priority of the UCI. Note that the base station device 102 may notify the terminal device 101 of the criteria for selecting the transport block into which the UCI to be transmitted should be multiplexed.

The base station device 102 transmits to the terminal device 101, for example, information that enables the terminal device 101 to identify the relationship between the priority of the UCI and the transport block into which the UCI should be multiplexed. The base station device 102 transmits such information, for example, by an RRC message. The base station device 102 notifies the terminal device 101 of information indicating the selection criteria for the transport block to be multiplexed (for example, high or low MCS, high or low target error rate, etc.) for each priority index. Note that only information that enables the selection of the transport block into which the UCI of high priority (for example, priority index = 1) should be multiplexed may be notified to the terminal device 101, and information about the UCI of low priority may not be notified. For example, information that the UCI of high priority should be multiplexed into the transport block using the MCS with the higher communication rate of the two transport blocks is notified from the base station device 102 to the terminal device 101. Then, when the transport block using the higher MCS in which the high priority UCI is multiplexed has enough free space to transmit the low priority UCI, at least a part of the low priority UCI may be multiplexed into that transport block. Then, when the size of the low priority UCI exceeds the free space of the transport block using the higher MCS in which the high priority UCI is multiplexed, it may be multiplexed into the other transport block. Note that the low priority UCI may always be multiplexed into the other transport block. Also, when the total number of bits (size) of the low priority UCI and the high priority UCI is equal to or less than a predetermined value, both the high priority UCI and the low priority UCI may be multiplexed into the transport block in which the high priority UCI is multiplexed, and otherwise, the high priority UCI and the low priority UCI may be multiplexed into separate transport blocks. The base station device 102 may notify the terminal device 101 of whether the low-priority UCI should be unconditionally multiplexed into a transport block different from the high-priority UCI, or whether the low-priority UCI should be multiplexed into the same transport block as the high-priority UCI if it can be multiplexed into that transport block. The base station device 102 may dynamically change the relationship between the priority of the UCI and the transport block to be multiplexed. In this case, the base station device 102 may transmit an individual message to the terminal device 101, for example, when a change is required. The base station device 102 may also notify the terminal device 101 of information indicating the relationship between the priority of the UCI and the transport block to be multiplexed, for example, periodically.

In this way, the base station device 102 notifies the terminal device 101 of an index for determining into which transport block the UCI should be multiplexed, so that the UCI can be multiplexed into an appropriate transport block under the control of the base station device 102. Furthermore, by performing dynamic control, the base station device 102 can cause the terminal device 101 to efficiently transmit UCI in response to changes in communication conditions and changes in communication policies.

In the above example, the base station device 102 transmits information that enables the terminal device 101 to identify the transport block into which the UCI is multiplexed based on the priority of the UCI, and the terminal device 101 performs a process of determining, for each UCI, the transport block into which the UCI should be multiplexed based on the information. In response to this, the base station device 102 may transmit to the terminal device 101 information that directly specifies into which transport block each UCI should be multiplexed. In this case, the terminal device 101 multiplexes the specified UCI into the transport block specified by the base station device 102. For example, when transmitting downlink user data (PDSCH), the base station device 102 notifies the terminal device 101 of information indicating the transport block into which the HARQ-ACK related to the user data should be multiplexed. For example, this notification may be performed using DCI. For example, the terminal device 101 is notified of information indicating which transport block the HARQ-ACK for the PDSCH should be multiplexed into by the DCI transmitted along with the transmission of the PDSCH. After that, the base station device 102 transmits an uplink grant for transmitting user data in two transport blocks to the terminal device 101. In response to this uplink grant, the terminal device 101 generates user data to be transmitted in each of the two transport blocks, and multiplexes the previously received HARQ-ACK for the PDSCH into the user data to be transmitted in the transport block specified by the DCI to generate two transport blocks. Then, the terminal device 101 performs predetermined processing such as modulation and mapping to the physical layer on the two generated transport blocks, and transmits them to the base station device 102 using the radio resources (frequency and time resources) specified in the uplink grant. In addition to the HARQ-ACK, when reporting CSI, information specifying the transport block into which the CSI should be multiplexed can be notified from the base station device 102 to the terminal device 101. For example, the base station device 102 can notify the terminal device 101 of a request for reporting CSI and information indicating in which of the two transport blocks the CSI should be multiplexed in an uplink grant for user data in two transport blocks. The terminal device 101 generates user data to be transmitted in each of the two transport blocks, multiplexes the CSI into the user data transmitted in the transport block specified by the DCI, and generates two transport blocks. The terminal device 101 then performs a predetermined process on the two generated transport blocks and transmits them to the base station device 102 using the radio resources specified in the uplink grant.

In this way, by the base station device 102 explicitly notifying information indicating which transport block the UCI should be multiplexed into, it is possible to ensure that the UCI is transmitted in the transport block determined by the base station device 102.

(Device configuration)
Next, the device configuration will be described. FIG. 2 shows an example of the hardware configuration of the base station device and the terminal device of this embodiment. In one example, the base station device and the terminal device are configured to include a processor 201, a ROM 202, a RAM 203, a storage device 204, and a communication circuit 205. The processor 201 is a computer configured to include one or more processing circuits such as a general-purpose CPU (Central Processing Unit) or an ASIC (Application Specific Integrated Circuit), and executes the overall processing of the device and each of the above-mentioned processes by reading and executing a program stored in the ROM 202 or the storage device 204. The ROM 202 is a read-only memory that stores information such as programs and various parameters related to the processing executed by the base station device and the terminal device. The RAM 203 functions as a workspace when the processor 201 executes a program, and is a random access memory that stores temporary information. The storage device 204 is configured, for example, by a removable external storage device. The communication circuit 205 is configured, for example, by a circuit for wireless communication of 5G or its successor standard. Although one communication circuit 205 is illustrated in FIG. 2, the base station device and the terminal device may have multiple communication circuits. For example, the base station device and the terminal device may have wireless communication circuits for 5G and its successor standards, and a common antenna for those circuits. The base station device and the terminal device may have separate antennas suitable for each standard. The base station device may further have a wired communication circuit used when communicating with other base station devices and nodes of the core network. The terminal device may further have a communication circuit conforming to a wireless communication standard other than the cellular communication standard, such as a wireless local area network (LAN) or Bluetooth (registered trademark). The base station device and the terminal device may have separate communication circuits 205 for each of the multiple available frequency bands, or may have a common communication circuit 205 for at least a part of those frequency bands.

Figure 3 shows an example of the functional configuration of the terminal device 101. The terminal device 101 has, for example, a multiplexing target identification unit 301, a transport block generation unit 302, and a wireless communication unit 303. Note that FIG. 3 shows only functions particularly related to this embodiment, and various other functions that the terminal device 101 may have are omitted from the illustration. For example, the terminal device 101 naturally has other functions that terminal devices that comply with 5G and its successor standards generally have. In addition, the functional blocks in FIG. 3 are shown in schematic form, and each functional block may be integrated and realized, or may be further subdivided. In addition, each function in FIG. 3 may be realized, for example, by the processor 201 executing a program stored in the ROM 202 or the storage device 204, or may be realized, for example, by a processor present inside the communication circuit 205 executing a predetermined software. Note that the details of the processing performed by each functional unit will not be described in detail here, and only the rough functions will be outlined.

The multiplexing target identification unit 301 determines in which of the multiple transport blocks the UCI to be transmitted by the terminal device 101 is to be multiplexed. For example, the multiplexing target identification unit 301 checks the priority index of the information to be transmitted as UCI and identifies the priority of each piece of information to be transmitted. Then, the multiplexing target identification unit 301 determines in which transport block the information is to be multiplexed based on the priority. For example, the multiplexing target identification unit 301 may determine that the high priority information is to be multiplexed in a transport block using an MCS with a relatively high communication rate, and that the low priority information is to be multiplexed in a transport block using an MCS with a relatively low communication rate. Note that the multiplexing target identification unit 301 may determine that at least one of the low priority information is to be multiplexed in the same transport block as the high priority information, as described above. The correspondence between the priority of other UCI and the transport block into which that UCI should be multiplexed can be modified as described above, and the multiplexing target identification unit 301 may determine, for example, to multiplex high-priority UCI in a transport block that uses an MCS with a low communication rate or a transport block with a low target error rate.

The multiplexing target identification unit 301 may also determine in which transport block the information to be transmitted as UCI should be multiplexed, based on information from the base station device 102. For example, the base station device 102 may notify information on the selection criteria for the transport block into which the UCI should be multiplexed, for each priority of the UCI. In this case, the multiplexing target identification unit 301 determines the priority of each piece of information to be transmitted as UCI, and determines the transport block into which the information should be multiplexed, based on the determination result and the information on the selection criteria received from the base station device 102. Furthermore, when the multiplexing target identification unit 301 receives information from the base station device that explicitly specifies the transport block into which the UCI should be multiplexed, it identifies the transport block into which the UCI should be multiplexed according to the information.

The transport block generation unit 302 transmits the transport block to be transmitted to the base station device 102. For example, when a DCI instructing to transmit two transport blocks in parallel is received from the base station device 102, the transport block generation unit 302 generates two transport blocks in parallel. At this time, the transport block generation unit 302 multiplexes the UCI into the transport block into which the multiplexing target specification unit 301 has determined that the UCI should be multiplexed, to generate a transport block. The wireless communication unit 303 transmits the generated transport block to the base station device 102. For example, the wireless communication unit 303 maps the generated transport block to a wireless resource specified by the base station device 102 and transmits it to the base station device 102.

Figure 4 shows an example of the functional configuration of the base station device 102. The base station device 102 has, for example, a multiplexing target determination unit 401 and a target information notification unit 402. Note that FIG. 4 shows an example of the configuration when the base station device 102 specifies a transport block into which UCI should be multiplexed to the terminal device 101. FIG. 4 shows only functions that are particularly related to this embodiment, and various other functions that the base station device 102 may have are omitted from the illustration. For example, the base station device 102 naturally has other functions that a base station device that complies with 5G or its successor standards generally has. In addition, the functional blocks in FIG. 4 are shown generally, and each functional block may be realized by being integrated together, or may be further subdivided. In addition, each function in FIG. 4 may be realized, for example, by the processor 201 executing a program stored in the ROM 202 or the storage device 204, or may be realized, for example, by a processor present inside the communication circuit 205 executing a predetermined software. Note that we will not go into the details of the processing performed by each functional unit here, but will outline only their general functions.

The multiplexing target determination unit 401 determines criteria that enable at least the terminal device 101 to identify the transport block into which the UCI to be transmitted from the terminal device 101 is multiplexed. The multiplexing target determination unit 401 may also explicitly determine the transport block into which the UCI to be transmitted by the terminal device 101 is to be multiplexed. The information notification unit 402 notifies the terminal device 101 of information that enables the terminal device 101 to identify the transport block into which the UCI is multiplexed.

(Processing flow)
5 shows an example of a process flow in which the terminal device 101 determines the transport block into which UCI is multiplexed by itself. In this process, the terminal device 101 first receives an instruction (uplink grant) to transmit two transport blocks in parallel from the base station device 102 (S501). When the terminal device 101 receives an instruction to transmit only one transport block, it multiplexes all the generated UCI into that transport block. On the other hand, when the terminal device 101 transmits two transport blocks in parallel and needs to transmit UCI, it determines in which transport block the UCI is multiplexed. For example, when a high-priority UCI occurs (YES in S502), the terminal device 101 multiplexes the UCI into a transport block using, for example, an MCS with a high communication rate (S503). This is only an example, and as described above, for example, the high-priority UCI may be multiplexed into a transport block using an MCS with a low communication rate (high error tolerance), or the high-priority UCI may be multiplexed into a transport block with a low target error rate. In addition, when a low-priority UCI occurs (YES in S504), the terminal device 101 determines which transport block the UCI is to be multiplexed into (S505). For example, when the sum of the sizes of the low-priority UCI and the high-priority UCI does not exceed a predetermined value, the terminal device 101 may determine that the low-priority UCI is also multiplexed into the transport block into which the high-priority UCI is multiplexed. In addition, the terminal device 101 multiplexes a part of the low-priority UCI into the transport block into which the high-priority UCI is multiplexed, and multiplexes the remaining part of the low-priority UCI into, for example, a transport block using an MCS with a low communication rate. Furthermore, the terminal device 101 may multiplex all of the low-priority UCI into a transport block that uses an MCS with a low communication rate. After that, the terminal device 101 generates and transmits a PUSCH including the transport block thus generated (S506).

In this way, when the terminal device 101 receives an instruction to transmit an uplink signal using two transport blocks and there is UCI to be transmitted, the terminal device 101 can multiplex the UCI into a transport block selected based on the priority of the UCI and transmit the UCI. In this procedure, for example, when high-priority UCI needs to be transmitted reliably, a selection criterion is set so that the high-priority UCI is multiplexed into a transport block that uses an MCS with a high communication rate (i.e., the wireless quality is assumed to be good) or a transport block with a low target error rate. According to such a procedure, by appropriately setting the selection criterion for the transport block into which the high-priority UCI is multiplexed, for example, the success rate of transmission of the UCI to the base station device 102 can be improved, and the UCI can be transmitted efficiently.

Figure 6 shows an example of a processing flow when the base station device 102 notifies the terminal device 101 of criteria information for the terminal device 101 to determine the transport block into which the UCI is multiplexed. In this processing, the base station device 102 notifies the terminal device 101 of criteria information for selecting the transport block into which the UCI is multiplexed for each priority index of the UCI (S601).

In FIG. 6, as an example of the reference information, an example is shown in which the base station device 102 notifies the terminal device 101 of the relationship information between the priority index of the UCI and the MCS used in the transport block into which the UCI should be multiplexed. The base station device 102 notifies the terminal device 101 of, for example, information indicating that the UCI with a high priority should be multiplexed into the first transport block of the two transport blocks that uses the MCS with a higher communication rate. At this time, information indicating that the UCI with a low priority should be multiplexed into the second transport block of the two transport blocks that uses the MCS with a lower communication rate may be notified to the terminal device 101. Also, information indicating that at least a part of the UCI with a low priority should be multiplexed into the first transport block may be notified to the terminal device 101. At this time, information on the size of the UCI that is allowed to be multiplexed into the first transport block may be notified to the terminal device 101. The terminal device 101 multiplexes low-priority UCI within the range of the allowed size in the first transport block, and multiplexes low-priority UCI exceeding the range of the size in the second transport block. Also, when the total size of high-priority UCI and low-priority UCI is equal to or smaller than a predetermined value, the terminal device 101 may be notified that all of the UCI should be multiplexed in the first transport block. In this case, the predetermined value may be notified from the base station device 102 to the terminal device 101. When the total size of high-priority UCI and low-priority UCI exceeds a predetermined value, the terminal device 101 may multiplex high-priority UCI in the first transport block, and low-priority UCI in the second transport block. That is, even if the size of the high-priority UCI is sufficiently small and there is remaining capacity in the first transport block to multiplex the low-priority UCI, the terminal device 101 may multiplex all of the low-priority UCI into the second transport block if the total size of the high-priority UCI and the low-priority UCI exceeds a predetermined value.

Then, the base station device 102 transmits an instruction to the terminal device 101 to transmit the PUSCH using two transport blocks in parallel (S602). Then, when the terminal device 101 receives the instruction to transmit the PUSCH using two transport blocks, it determines the priority of the UCI to be transmitted, and multiplexes the UCI into at least one of the two transport blocks based on the priority and the information received in S601 (S603). The terminal device 101 may multiplex this UCI, for example, as shown in FIG. 5. However, the criteria provided by the base station device 102 in S601 are used as the selection criteria for the transport block into which the UCI is multiplexed in S503 and S505. Then, the terminal device 101 transmits an uplink signal to the base station device 102 using the two transport blocks into which the UCI is multiplexed in this way (S604).

In this way, the base station device 102 provides a selection criterion for the transport block into which the UCI should be multiplexed, and the terminal device 101 can multiplex and transmit the UCI into an appropriate transport block based on the priority of the UCI. For example, when the amount of data of high-priority UCI is large, the selection criterion can be determined so that the UCI is multiplexed into a transport block in which an MCS with a high communication rate is used (i.e., the wireless quality is assumed to be good). In addition, in order to ensure that the high-priority UCI is transmitted, the selection criterion can be set so that the high-priority UCI is multiplexed into a transport block with a low target error rate. According to such a procedure, it becomes possible to appropriately set the selection criterion for the transport block into which the high-priority UCI is multiplexed on the network side, and the terminal device 101 can efficiently transmit the UCI via an appropriate transport block depending on the situation.

Figures 7 and 8 show an example of a processing flow when the base station device 102 notifies the terminal device 101 of information explicitly indicating the transport block in which the UCI is multiplexed. Note that Figure 7 shows an example in which HARQ-ACK is transmitted as UCI, while Figure 8 shows an example in which CSI is transmitted as UCI. In Figure 7, the base station device 102 transmits downlink data (PDSCH) to the terminal device 101 (S701). At this time, via a control signal (PDCCH) transmitted in association with the PDSCH, in addition to information on the radio resources used to transmit the downlink data, information indicating which transport block the HARQ-ACK for the downlink data should be multiplexed is notified to the terminal device 101. After that, the base station device 102 transmits an uplink grant for transmitting uplink user data using two transport blocks to the terminal device 101 (S702). The terminal device 101 generates user data to be transmitted in each of the two transport blocks, and multiplexes the HARQ-ACK related to the downlink data received in S701 onto the user data (S703). At this time, the terminal device 101 multiplexes the HARQ-ACK in the transport block specified by the base station device 102. The terminal device 101 then transmits the two generated transport blocks to the base station device 102 (S704).

In FIG. 8, the base station device 102 transmits an uplink grant to the terminal device 101 requesting the transmission of CSI when transmitting uplink user data using two transport blocks (S801). At this time, information indicating which transport block the CSI should be multiplexed into is notified to the terminal device 101. The terminal device 101 generates user data to be transmitted in each of the two transport blocks, and multiplexes the user data with CSI obtained by separately measuring wireless quality (S802). Then, the terminal device 101 transmits the two generated transport blocks to the base station device 102 (S803).

In this way, the base station device 102 explicitly specifies the transport block into which the UCI should be multiplexed, and the terminal device 101 can multiplex and transmit the UCI in an appropriate transport block. Here, the base station device 102, for example, determines the priority of the UCI to be transmitted by the terminal device 101, and determines into which transport block the UCI should be multiplexed based on the priority. For example, in order to ensure that the high-priority UCI is transmitted, the base station device 102 can determine a transport block with a low target error rate as the transport block into which the high-priority UCI is multiplexed. According to such a procedure, it becomes possible to appropriately set the transport block into which the high-priority UCI is multiplexed on the network side, and the terminal device 101 can efficiently transmit the UCI via an appropriate transport block depending on the situation.

As described above, in this embodiment, it is possible to efficiently transmit uplink control information. This makes it possible to contribute to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs), which is to "build resilient infrastructure, promote sustainable industrialization, and foster innovation."

The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the invention.

Claims (9)

A terminal device,
a determination means for determining a priority of uplink control information (UCI) to be transmitted together with user data when the user data is transmitted to a base station device by using a first transport block and a second transport block in parallel;
a determining means for determining in which of the first transport block and the second transport block the UCI should be multiplexed with user data based on the priority;
a transmitting means for generating the first transport block and the second transport block by multiplexing user data and the UCI in a transport block in which it has been determined that the UCI should be multiplexed, and transmitting the first transport block and the second transport block to the base station device;
A terminal device comprising: the priority is either a first priority or a second priority lower than the first priority,
The first transport block is configured to use a modulation and coding scheme (MCS) having a higher communication rate than the second transport block;
2. The terminal device according to claim 1, wherein the determining unit determines that the UCI having the first priority is multiplexed in the first transport block. the priority is either a first priority or a second priority lower than the first priority,
A target error rate of the first transport block is set to be lower than that of the second transport block;
2. The terminal device according to claim 1, wherein the determining unit determines that the UCI having the first priority is multiplexed in the first transport block. the priority is either a first priority or a second priority lower than the first priority,
the first transport block is a transport block for performing ultra-reliable and low-latency communication (URLLC), and the second transport block is a transport block for communication different from the URLLC;
2. The terminal device according to claim 1, wherein the determining unit determines that the UCI having the first priority is multiplexed in the first transport block. The terminal device according to any one of claims 2 to 4, characterized in that the determination means determines that the UCI whose priority is the second priority is to be multiplexed in the second transport block. The terminal device according to any one of claims 2 to 4, characterized in that the determination means determines to multiplex a portion of the UCI having the second priority in the first transport block and to multiplex a remaining portion of the UCI having the second priority in the second transport block. The terminal device according to any one of claims 2 to 4, characterized in that the determining means determines to multiplex the UCI having the second priority in the first transport block when the total size of the UCI having the first priority and the UCI having the second priority is equal to or less than a predetermined value, and to multiplex the UCI having the second priority in the second transport block when the total size of the UCI having the first priority and the UCI having the second priority exceeds a predetermined value. A control method executed by a terminal device, comprising:
determining a priority of uplink control information (UCI) to be transmitted together with user data when the user data is transmitted to a base station device by using a first transport block and a second transport block in parallel;
determining in which of the first transport block and the second transport block the UCI should be multiplexed with user data based on the priority;
generating the first transport block and the second transport block by multiplexing user data and the UCI in a transport block in which it has been determined that the UCI should be multiplexed, and transmitting the first transport block and the second transport block to the base station device;
A control method comprising: A program for causing a computer installed in a terminal device to execute the control method described in claim 8.

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