JP2022154662A - Terminal device, base station device, communication method, and program using extended acknowledgment - Google Patents

Abstract

To provide an automatic retransmission control technique adaptable to diversification of a communication demand.SOLUTION: A terminal device acquires, from a base station device, information obtained by associating the number of bits of uplink control information to be transmitted to the base station device with a resource for transmitting the uplink control information of the number of bits, identifies the second number of bits of uplink control information to be transmitted to the base station device on the basis of the first number of bits required to transmit an acknowledgment with accompanying information on the reception status of user data from the base station device, and transmits the uplink control information including an acknowledgment to the base station device using the resource associated with the second number of bits.SELECTED DRAWING: Figure 5

Description

The present invention relates to an extension technique for acknowledgment in automatic retransmission control.

In the cellular communication standard of the 3rd Generation Partnership Project (3GPP), a mechanism is used in which the transmitting side and the receiving side share whether or not the radio frame has been successfully transmitted and received using the multiple automatic repeat request (HARQ). there is According to this mechanism, for example, when a radio frame transmitted from the base station device to the terminal device is normally received, the terminal device transmits an acknowledgment (ACK) associated with the radio frame to the base station device, If the radio frame is not received normally, it transmits a negative acknowledgment (NACK) associated with the radio frame to the base station apparatus. Upon receiving NACK, the base station apparatus retransmits a radio frame containing the same data or another redundancy version radio frame generated based on the data. This makes it possible to improve the reliability of data transmission from the base station apparatus to the terminal apparatus. Similarly, it is also possible to improve the reliability of data transmission from the terminal device to the base station device.

The base station apparatus can further identify the probability of data transmission failure (frame error rate) by counting the number of times ACK is received and the number of times NACK is received. For example, when the identified frame error rate is higher than a target predetermined value, the base station apparatus changes the modulation and coding scheme (MCS) to a scheme that is less susceptible to noise and interference. In addition, when the frame error rate is sufficiently lower than the target predetermined value, the base station apparatus changes the MCS to a scheme with a relatively high communication rate and relatively susceptible to noise and interference. sell. Thereby, the reliability of communication can be improved without excessively suppressing the communication rate.

In ultra-reliable communication, it is assumed that a very low value is used as the target value of the error rate. In such a case, it is assumed that almost all frames can be normally received by the device that receives the frames. In such a case, it is assumed that most frames are received successfully and no NACKs are sent or received unless the number of ACK/NACKs sent and received is very high. For this reason, for example, when one NACK is transmitted and received due to momentary deterioration in communication quality, the second MCS with a lower communication rate than the first MCS suitable for the actual communication environment is used. can be Also, in order to determine that the first MCS suitable for the original communication environment should be used after the use of the second MCS is started, it is necessary to transmit and receive a huge number of radio frames. Thus, conventional HARQ mechanisms may not be able to adapt to the diversification of communication demands.

The present invention provides advanced techniques for automatic repeat control such as HARQ.

A terminal apparatus according to an aspect of the present invention stores information associating the number of bits of uplink control information to be transmitted to a base station apparatus and the resource for transmitting the uplink control information of the number of bits to the base station apparatus. Uplink control information to be transmitted to the base station apparatus based on an acquisition means to acquire from and a first number of bits required for transmission of an acknowledgment accompanied by accompanying information on the reception status of user data from the base station apparatus. and transmitting means for transmitting uplink control information including the acknowledgment to the base station apparatus using the resource associated with the second number of bits. and have

A base station apparatus according to one aspect of the present invention transmits information that associates the number of bits of uplink control information to be received from a terminal apparatus with a resource for transmitting uplink control information of the number of bits to the terminal apparatus. a notification means for notifying, a transmission means for transmitting user data to the terminal device, and a reception means for receiving an acknowledgment accompanied by accompanying information regarding a reception status of the user data in the terminal device, wherein the acknowledgment is transmitted receiving means for receiving the acknowledgment on the resource associated with a second number of bits identified as the number of bits required to transmit uplink control information based on the first number of bits required for transmission of uplink control information.

According to the present invention, it is possible to provide an automatic retransmission control technology that can adapt to diversification of communication requests.

It is a figure which shows the structural example of a radio|wireless communications system. It is a figure which shows the hardware structural example of a base station apparatus and a terminal device. It is a figure which shows the functional structural example of a terminal device. It is a figure which shows the functional structural example of a base station apparatus. 1 is a diagram for outlining the flow of processing executed in a radio communication system; FIG.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more of the features described in the embodiments may be combined arbitrarily. Also, the same or similar configurations are denoted by the same reference numerals, and redundant explanations are omitted.

(System configuration)
FIG. 1 shows a configuration example of a wireless communication system according to this embodiment. This radio communication system can be a cellular communication system including base station apparatus 101 and terminal apparatus 102 . The base station apparatus 101 and the terminal apparatus 102 perform wireless communication according to any generation of 3GPP cellular wireless communication standards. For example, the base station apparatus 101 broadcasts basic control information, and the terminal apparatus 102 acquires the control information. Then, the terminal device 102 establishes a connection with the base station device 101 by executing a procedure such as a random access procedure based on the control information, for example. Thereafter, downlink user data is transmitted from the base station apparatus 101 to the terminal apparatus 102 , and uplink user data is transmitted from the terminal apparatus 102 to the base station apparatus 101 . The base station apparatus 101, for example, transmits information specifying resources (frequency/time resources) when transmitting downlink user data in downlink control information (DCI), and the terminal apparatus 102 transmits based on the DCI. receive user data at the resource identified by In addition, the base station apparatus 101 uses DCI to specify uplink resources to be used by the terminal apparatus 102, and the terminal apparatus 102 uses the specified resources to transmit uplink user data to the base station apparatus. 101.

It should be noted that the communication of user data may use combined automatic repeat request (HARQ). For example, when the terminal device 102 receives downlink user data from the base station device 101 , the terminal device 102 transmits an acknowledgment indicating the reception result to the base station device 101 . Note that the base station apparatus 101 may transmit an HARQ acknowledgment for user data transmitted from the terminal apparatus 102 . Acknowledgments generally include a positive acknowledgment (ACK) that is sent if user data is successfully received and a negative acknowledgment (NACK) that is sent if user data is unsuccessfully received. Note that, for example, when user data encoded using an error correction code is decoded by a corresponding decoding method, and a CRC (Cyclic Redundancy Check) of the decoding result determines that there is no error in the decoding result, It is determined that the user data has been successfully received. On the other hand, if the CRC does not indicate that the decoded result contains no error, it is determined that the user data has failed to be received.

In one example, the error correction code can be an LDPC (Low Density Parity Check) code or a polar code. User data of a fixed size is encoded with an error correction code to generate one codeword. Decoding may be performed on a codeword-by-codeword basis. Decoding may also use an iterative decoding method in which the decoding process for one codeword is iteratively performed (eg, using soft-decision values). In this case, it is possible to use the CRC to determine whether the decoding result obtained during the iteration of the decoding process contains an error. In this case, if the decoding result obtained midway does not contain an error, the repetition of the decoding process may be terminated.

The terminal device 102 transmits uplink control information (UCI) including an HARQ acknowledgment. At this time, the terminal device 102 transmits an acknowledgment for each codeword. UCI is transmitted by, for example, a physical uplink control channel (PUCCH). For this reason, when a plurality of codeword numbers are transmitted at once by carrier aggregation or the like, a state may arise in which a plurality of acknowledgments should also be transmitted at once. In this case, the terminal device 102 will transmit an acknowledgment with the number of bits corresponding to the number of codewords in the UCI. That is, the number of UCI bits can be variable.

At this time, the base station apparatus 101 transmits to the terminal apparatus 102 information that associates the number of bits to be transmitted in UCI with one or more resources in which the UCI is to be transmitted. After specifying the number of bits of UCI to be transmitted, the terminal device 102 specifies a resource corresponding to the number of bits based on the information, and transmits the UCI on that resource. For example, the base station apparatus 101 uses a first resource when the number of UCI bits is equal to or less than a first predetermined number of bits, and a first resource when the number of bits is greater than the first predetermined number of bits and equal to or less than a second predetermined number of bits. Information that associates the resource with the number of bits, such as a second resource, . . . , is transmitted. Then, the terminal device 102 transmits the UCI using the second resource, for example, in a situation where the UCI with the number of bits greater than the first predetermined number and equal to or less than the second predetermined number of bits should be transmitted. Note that the base station apparatus 101 can know in advance the number of bits of UCI to be transmitted by the terminal apparatus 102, for example, based on the number of codewords transmitted in parallel. You can know in advance which resources to send.

Note that there may be a plurality of resources associated with each number of bits, and in this case, the base station apparatus 101 can notify the terminal apparatus 102 of information specifying which of the plurality of resources should be used. . That is, the base station apparatus 101 uses resource 0 to resource N1-1 when the number of bits of the UCI is equal to or less than the first predetermined number of bits, and Information that associates resource sets and bit numbers, such as resource N1 to resource N2-1, . . . , is transmitted. Then, for example, the base station apparatus 101 should use the resource N1+3 (the fourth resource in the set of resources) when the number of UCI bits is greater than the first predetermined number of bits and equal to or less than the second predetermined number of bits. , the terminal device 102 can be notified to use the “fourth” resource, for example. Thereby, the terminal device 102 specifies the resource N1 to resource N2-1 by determining that the number of bits of the UCI to be transmitted is greater than the first predetermined number of bits and equal to or less than the second predetermined number of bits, and furthermore, A resource N1+3, which is the fourth resource among the resources, can be identified and the UCI can be transmitted on that resource.

The base station apparatus 101 can be configured to determine the modulation and coding scheme (MCS) to use on the radio link based on HARQ acknowledgments and retransmissions. For example, the target frame error rate is set based on the quality of service (for example, indicated by QCI (QoS Class Indicator) or the like) in communication with the terminal device 102 . Then, the base station apparatus 101 can set the MCS such that, for example, the ratio of the number of NACK receptions to the number of downlink user data transmissions approaches the target frame error rate. Similarly, the base station apparatus 101 may operate to change the MCS to be used by the terminal apparatus 102, for example, based on the number of reception failures (the number of NACK transmissions) relative to the number of receptions of uplink user data. good. This makes it possible to adaptively select and use an MCS suitable for the communication environment. At this time, if the frame error rate of the target is extremely low, it takes a huge number of codes to determine whether or not the MCS being used is appropriate based only on acknowledgments consisting of binary values of ACK and NACK. Words must be sent and received. Furthermore, the communication environment changes while such a large number of codewords are being transmitted and received, making it difficult to select an appropriate MCS.

In view of such circumstances, the present embodiment enhances the HARQ acknowledgment, thereby making it possible to set the MCS used in the radio link with high accuracy. In this embodiment, in one example, the acknowledgment is configured so that the information can be expressed in three or more stages instead of binary ACK and NACK.

For example, when an iterative decoding method that repeatedly performs decoding of one codeword is used, and the codeword is successfully decoded (that is, the user data is successfully received), the iterative decoding method The number of successful iterations may be sent in the acknowledgment. That is, the acknowledgment is configured so that when ACK is transmitted in the acknowledgment, the number of iterations for successful decoding is transmitted as accompanying information accompanying successful reception of the user data. For example, if the number of iterations of the process until successful decoding is small (eg, once), it can be evaluated that the radio quality is excessively good. On the other hand, if the number of iterations of processing until successful decoding is the preset maximum number of iterations, the codeword is successfully decoded, but if the radio quality degrades even a little, can be evaluated as having a certain probability of decoding failure. For this reason, the base station apparatus 101, for example, based on the acknowledgment accompanied by the accompanying information, so that the number of iterations when the decoding is successful approaches a predetermined number (for example, more than 1 and less than the maximum number of times). , can determine the MCS to use. Note that the number of iterations may be expressed with various granularities, and the more the number of possible values of the accompanying information, the finer the granularity indicating the number of iterations can be set.

In one example, an acknowledgment with side information can be represented by 4 values (2 bits). In this case, for example, "01" if the codeword is successfully decoded in one decoding process, "10" if the decoding is successful in two to nine decoding processes, and 10 times to the maximum number of iterations. "11" can be sent as an acknowledgment when the decoding process succeeds in decoding, and "00" when the decoding fails. Also, an acknowledgment accompanied by accompanying information may be expressed in 8 values (3 bits). In this case, "001" if the code word is successfully decoded in one decoding process, "010" if the code word is successfully decoded in two or three decoding processes, "011" when decoding is successful, "100" when decoding is successful after 6 to 7 decoding processes, "101" when decoding is successful after 8 to 9 decoding processes, 10 times "110" when decoding is successful in decoding processing up to 11 times, "111" when decoding is successful in decoding processing from 12 times to the maximum number of iterations, and "000" when decoding fails. can be sent as Note that these are only examples, and the relationship between the bit string and the number of times of decoding may be associated with a correspondence relationship different from the above example, or, for example, an acknowledgment of 4 bits or more may be used. Also, in the above example, the case where the acknowledgment accompanied by the accompanying information can take the number of powers of 2 has been described, but the number of possible values may not be the number of powers of 2.

Also, when receiving user data, for example, using a known signal such as DMRS (Demodulation Reference Signal), measure the radio quality such as SINR (Signal to Interference plus Noise Ratio), and indicate the radio quality of the measurement result An acknowledgment including the value as ancillary information may be sent and received. Other quantities such as SNR (Signal to Noise Ratio), RSSI (Received Signal Strength Indicator), RSRP (Reference Signal Received Power), and RSRQ (Reference Signal Received Quality) may be used as radio quality. The radio quality may be transmitted/received as information accompanying an acknowledgment when codeword demodulation is successful, or may be transmitted/received as information accompanying a negative acknowledgment when codeword demodulation is unsuccessful. good. That is, even if the decoding is successful, whether the radio quality is insufficient, sufficient, or excessive is transmitted and received as accompanying information, so that the communication status It is possible to set the MCS suitable for Also, when decoding fails, it is possible to appropriately select which MCS to use according to radio quality. That is, when the accompanying information is not used, even if it is necessary to change the MCS significantly for successful decoding (that is, to select an MCS that is highly resistant to interference and noise), Changing the MCS can lead to persistent decoding errors. On the other hand, by sending and receiving acknowledgments with associated information, it becomes possible to set an appropriate MCS at once.

It should be noted that the radio quality information and the above iteration count information may be used in combination. For example, the acknowledgment with side information may be configured to indicate the number of iterations in case of successful decoding and the radio quality in case of unsuccessful decoding. Also, in this case, when the decoding is successful, the radio quality may be notified in addition to the number of iterations.

The base station apparatus 101 determines whether to use an acknowledgment with side information or an acknowledgment without side information based on, for example, the quality of service and the frame error rate value of the corresponding target. sell. Then, the base station apparatus 101 notifies the terminal apparatus 102 of the determined content. As a result, the terminal device 102 can recognize whether to use only ACK/NACK as before or to use an acknowledgment to report the communication status in more detail with accompanying information. For example, when the target frame error rate is lower than a predetermined value, such as when a communication service that requires ultra-high reliability is provided, the acknowledgment with accompanying information is used. An acknowledgment without a Also, for example, the lower the target frame error rate, the greater the amount of information in the acknowledgment with accompanying information (eg, more bits, more possible values). By increasing the amount of information in the acknowledgment that accompanies the accompanying information, the reception status can be expressed in more detail. Based on this detailed information, detailed and appropriate MCS settings can be made. becomes. Here, a case will be described where the base station apparatus 101 transmits user data to the terminal apparatus 102, and the terminal apparatus 102 transmits an acknowledgment (including accompanying information as necessary) to the base station apparatus 101. , but not limited to this. That is, the enhancement of acknowledgment as described above can be used in a system in which a detailed report of the reception status is useful, such as radio link control based on the success or failure of reception of HARQ or the like.

When receiving downlink user data from the base station apparatus 101, the terminal apparatus 102 of the present embodiment receives an acknowledgment indicating the reception status of the user data, and when receiving an instruction from the base station apparatus 101, sends an acknowledgment with accompanying information to base station apparatus 101 . Here, the number of bits of the acknowledgment to be transmitted changes depending on the presence or absence of the accompanying information and the contents of the accompanying information. For this reason, the terminal apparatus 102 of this embodiment first identifies the first number of bits required for transmission of an acknowledgment, and based on the first number of bits, the uplink data to be transmitted to the base station apparatus 101. A second number of bits of control information (UCI) is identified. Note that the UCI may include, for example, information indicating the state of the downlink channel (CSI, Channel State Information), and when specifying the second number of bits of the UCI, the first Not only the number of bits but also all information to be transmitted to such base station apparatus 101 are considered. Then, the terminal device 102 identifies the resource corresponding to the identified second number of bits based on the information associating the number of UCI bits and the resource notified from the base station device 101 as described above. The terminal device 102 then uses the resource to transmit the UCI including the acknowledgment. That is, in the present embodiment, when the number of bits of UCI increases due to transmission of accompanying information, a resource to be used is selected according to the increase in the number of bits, and UCI is transmitted using that resource. .

On the other hand, since the base station apparatus 101 according to the present embodiment knows in advance what kind of accompanying information an acknowledgment will be received, similarly to the terminal apparatus 102, the first A number of bits and a second number of bits of the UCI can be specified. Therefore, after transmitting user data to the terminal device 102, the base station device 101 specifies in advance which resource will receive an acknowledgment (accompanied by accompanying information as necessary) to the user data. can do. Therefore, the base station apparatus 101 receives the UCI including the acknowledgment from the terminal apparatus 102 using the identified resource. In addition, when a plurality of resources are individually associated with the number of bits of UCI, the base station apparatus 101 transmits information specifying which of the plurality of resources should be used to the terminal apparatus 102 in a conventional manner. may notify you.

Note that the presence or absence of the accompanying information and the content of the accompanying information may be determined in advance, or the base station apparatus 101 may notify the terminal device 102 of designation information specifying the presence or absence of the accompanying information and the content of the accompanying information. good. The designation information can be sent individually to the terminal device 102 using, for example, an RRC (radio resource control) message. According to this, the first bit number of the UCI is specified assuming that an acknowledgment indicating only whether or not the user data has been successfully received is transmitted when the specifying information indicates that the accompanying information is not transmitted. be. The specified first number of bits is the same as the number of bits when only conventional ACK/NACK is transmitted, and the acknowledgment for one acknowledgment is 1 bit. On the other hand, when the designation information indicates that the accompanying information is to be transmitted, the first number of bits is specified based on the number of bits required to express the contents of the accompanying information designated by the designation information. For example, if the acknowledgment with accompanying information can take any of four values, the number of bits required for one acknowledgment is 2 bits. Also, if the acknowledgment with accompanying information can take any one of eight values, the number of bits required for one acknowledgment is 3 bits. Once the number of bits required for one acknowledgment is determined in this way, for example, the number of acknowledgments (the number of codewords) is multiplied to obtain the first bit required for transmission of the entire acknowledgment. number can be specified.

Note that the presence or absence of accompanying information and the content of accompanying information may be uniquely specified based on the service type, for example. This is useful when the target frame error rate is determined by the service type. In this case, since the terminal device 102 can specify the presence or absence of the accompanying information and the content of the accompanying information according to the communication service provided to the terminal device 102, there is no need to separately receive the designation information from the base station device 101. . Further, the presence or absence of accompanying information and the contents of accompanying information may be set separately for each of a plurality of codewords. For example, when the terminal device 102 is provided with a plurality of services, settings regarding accompanying information may be made separately for each of the plurality of services. In this case, the presence or absence of accompanying information and the content of accompanying information for each service may be specified by specifying information, or may be uniquely specified corresponding to the service.

Note that, when resources for transmitting user data on the uplink are allocated, the terminal device 102 can transmit an acknowledgment using those resources. That is, the acknowledgment, optionally accompanied by additional information, may be multiplexed with uplink user data and transmitted together with the user data.

As described above, in the present embodiment, by enhancing the HARQ acknowledgment, the terminal device 102 can notify the base station device 101 of the reception status of user data in detail. According to this, the base station apparatus 101 can adaptively adjust the MCS and the like used for transmitting user data regardless of success or failure of reception. Therefore, based on a small number of acknowledgments, it is possible to set a radio link so that an appropriate MCS is used. Note that such advanced acknowledgments can be used in any system that uses acknowledgments such as HARQ and ARQ, and can also be applied to acknowledgments for user data transmitted from the terminal device 102. Also, any wireless communication device other than the base station device 101 and the terminal device 102 can use this technique.

(Equipment configuration)
Next, a hardware configuration example of the base station apparatus 101 and the terminal apparatus 102 that execute the processes described above will be described with reference to FIG. The base station device 101 and the terminal device 102 are configured including a processor 201 , a ROM 202 , a RAM 203 , a storage device 204 and a communication circuit 205 in one example. The processor 201 is a computer including one or more processing circuits such as a general-purpose CPU (Central Processing Unit) and ASIC (Application Specific Integrated Circuit). By reading and executing the program stored therein, the overall processing of the base station apparatus 101 and the terminal apparatus 102 and each of the above-described processes are executed. The ROM 202 is a read-only memory that stores programs related to processing executed by the base station apparatus 101 and the terminal apparatus 102 and information such as various parameters. A RAM 203 is a random access memory that functions as a work space when the processor 201 executes programs and stores temporary information. The storage device 204 is configured by, for example, a detachable external storage device or the like. The communication circuit 205 is configured by, for example, a circuit for 5G wireless communication. Although one communication circuit 205 is illustrated in FIG. 2, the base station apparatus 101 and the terminal apparatus 102 can have multiple communication circuits. For example, the base station apparatus 101 and terminal apparatus 102 may have separate communication circuits 205 for each of a plurality of usable frequency bands. Also, the base station apparatus 101 and the terminal apparatus 102 may have a common communication circuit 205 for at least some of the multiple frequency bands. Further, for example, the terminal device 102 may have not only the communication circuit 205 for cellular communication, but also the communication circuit 205 compatible with other wireless communication standards such as wireless LAN.

FIG. 3 is a diagram showing a functional configuration example of the terminal device 102. As shown in FIG. The terminal device 102 has, for example, an information acquisition section 301, a bit number identification section 302, a resource identification section 303, a reception status determination section 304, and an acknowledgment transmission section 305 as its functions. Note that FIG. 3 shows only functions particularly related to the present embodiment, and omits illustration of various other functions that the terminal device 102 may have. For example, the terminal 102 naturally has other functionality that terminals typically have in cellular communication systems. Moreover, the functional blocks in FIG. 3 are shown schematically, and each functional block may be integrated and realized, or may be further subdivided. Each function in FIG. 3 may be implemented by, for example, the processor 201 executing a program stored in the ROM 202 or the storage device 204. For example, the processor inside the communication circuit 205 may execute a predetermined It may be implemented by executing software. Note that the details of the processing executed by each functional unit will not be described here, and only the general functions thereof will be described.

The information acquisition unit 301 acquires information that associates the number of bits of uplink control information to be transmitted to the base station apparatus 101 and the resource to which the uplink control information of that number of bits is to be transmitted. Information acquisition section 301 can acquire this information from base station apparatus 101, for example. Note that this information may be broadcast-transmitted, or may be transmitted individually to the terminal device 102 . Further, when a plurality of resources are associated with one bit number value, the information acquisition unit 301 can acquire predetermined information specifying which of them should be used. For example, this predetermined information can be signaled by downlink control information (DCI). The information acquisition unit 301 also determines, for example, whether or not to transmit an acknowledgment accompanied by accompanying information, and if the acknowledgment accompanied by accompanying information should be transmitted, what content should be used for the acknowledgment. Designated designation information may be obtained. Note that when the presence or absence of accompanying information and the content of the accompanying information are predetermined for each service type, the information acquisition unit 301 only needs to acquire information specifying the service type, and does not need to acquire the specifying information. no.

The number-of-bits specifying unit 302 specifies the number of bits of one acknowledgment based on the information amount of the acknowledgment specified based on the designation information acquired by the information acquiring unit 301, for example. Multiply by the number of codewords to determine the number of bits required to transmit the acknowledgment. Note that the number-of-bits specifying unit 302 may individually specify the number of bits of the acknowledgment for each codeword, and specify the sum of the number of bits as the number of bits required to transmit the acknowledgment. Also, the number-of-bits identifying section 302 identifies the number of bits required to transmit the UCI, further considering other information to be transmitted in the UCI, such as the CSI value indicating the state of the downlink channel.

Resource identifying section 303 identifies resources associated with the number of bits identified by number-of-bits identifying section 302 based on the information obtained by information obtaining section 301 . The reception status determination unit 304 determines whether or not the user data received from the base station apparatus 101 has been successfully decoded. Radio quality information such as the SINR of the signal may be determined. The acknowledgment sending unit 305 generates an acknowledgment with accompanying information as needed, and information indicating whether the reception was successful or not determined by the reception status determination unit 304 and the reception status, for example, according to the specified information. The acknowledgment is sent using the resource identified by unit 303 .

FIG. 4 is a diagram showing a functional configuration example of the base station apparatus 101. As shown in FIG. The base station apparatus 101 has, for example, an information notification section 401, a user data transmission section 402, and an acknowledgment reception section 403 as its functions. Note that FIG. 4 shows only functions particularly related to the present embodiment, and omits illustration of various other functions that the base station apparatus 101 may have. For example, the base station device 101 naturally has other functions that base station devices in a cellular communication system generally have. Moreover, the functional blocks in FIG. 4 are shown schematically, and each functional block may be integrated and realized, or may be further subdivided. 4 may be implemented by the processor 201 executing a program stored in the ROM 202 or the storage device 204, for example. It may be implemented by executing software. Note that the details of the processing executed by each functional unit will not be described here, and only the general functions thereof will be described.

The information notification unit 401 transmits information that associates the number of bits of uplink control information to be transmitted by the terminal device 102 to the base station apparatus 101 and the resource to which the uplink control information of the number of bits is to be transmitted. to notify. Note that this information may be broadcast-transmitted, or may be transmitted individually to the terminal device 102 . Further, when the information notification unit 401 notifies the terminal device 102 of information in which a plurality of resources are associated with one bit number value, the information notification unit 401 further indicates which of the plurality of resources should be used. The designated predetermined information can be notified to the terminal device 102 . For example, this predetermined information can be signaled by downlink control information (DCI). The information notification unit 401 also determines, for example, whether or not to transmit an acknowledgment with accompanying information, and, if the acknowledgment with accompanying information should be sent, what content the acknowledgment should be sent with. The designation information to be designated may be notified to the terminal device 102 . If the presence or absence of accompanying information and the contents of the accompanying information are predetermined for each service type, the information notification unit 401 only needs to notify the information specifying the service type, and it is necessary to notify the designated information. no.

A user data transmission unit 402 transmits user data to the terminal device 102 . This transmission of user data is done in a conventional manner and will not be described in detail here. The acknowledgment receiving unit 403, for example, based on the first number of bits of the acknowledgment specified corresponding to the designation information notified to the terminal device 102, determines the second number of UCI to be transmitted from the terminal device 102. Specify the number of bits. Then, the acknowledgment receiving unit 403, in the resource associated with the specified second number of bits of the UCI (if a plurality of resources are associated, the resource further specified among them), from the terminal device 102 Execute the process of receiving the UCI including the acknowledgment.

(Processing flow)
Next, an example of the flow of processing executed by the base station apparatus 101 and the terminal apparatus 102 according to this embodiment will be outlined using FIG. Note that this is an example, and the base station apparatus 101 and the terminal apparatus 102 may perform various types of processing as illustrated above.

In this process, first, the base station apparatus 101 is associated with the number of bits of the UCI via, for example, a broadcast SIB (System Information Block), and the number of bits to be used when transmitting the UCI of the number of bits. Information indicating resources is transmitted to the terminal device 102 (S501). Note that this information may be notified individually to the terminal device 102 using, for example, an RRC message. In addition, the base station apparatus 101 individually notifies the terminal apparatus 102 of confirmation response setting information using, for example, an RRC message (S502). The setting information of the acknowledgment includes the presence/absence of accompanying information, and the content of the accompanying information if accompanying information (for example, information that associates the bit string indicated by the acknowledgment with the information to be transmitted). After that, the base station device 101 transmits user data to the terminal device 102 (S503).

Upon receiving the user data, the terminal device 102 determines the reception status of the user data (S504). Here, the terminal device 102 determines whether or not the reception of the user data (decoding of the codeword) is successful, and when transmitting an acknowledgment with accompanying information, the terminal device 102 corresponds to the content of the accompanying information. Then, the radio quality, the number of iterations of the decoding process by the iterative decoding method, and the like are determined. In addition, the terminal device 102 determines whether or not the acknowledgment is accompanied by accompanying information, the number of bits required to express the content of the accompanying information, and the number of bits required to transmit the acknowledgment based on the number of codewords to be received. The number is specified (S505). In addition, the terminal device 102 determines the number of bits required to transmit uplink control information (UCI) considering other information to be transmitted with the acknowledgment, eg, CSI (S506). Note that the order of the processing of S503 and S504 and the processing of S505 and S506 may be reversed. That is, the terminal device 102 specifies in advance the number of bits of the acknowledgment (and the number of bits of the UCI), for example, based on the configuration of the acknowledgment and the number of codewords, and then receives the user data. The reception status may be determined. Also, these processes may be performed in parallel. The terminal device 102 refers to the information received in S501, identifies the resource corresponding to the number of bits of the UCI identified in S506 (S507), and uses the resource to transmit the UCI including the acknowledgment ( S508).

As described above, in the present embodiment, by constructing an acknowledgment with accompanying information, not only whether the user data has been received successfully but also whether the user data has been received successfully/failed under what circumstances. It becomes possible for the base station apparatus 101 to recognize whether. This allows the base station apparatus 101 to appropriately control the radio link with the terminal apparatus 102 in various situations.

The invention is not limited to the above embodiments, and various modifications and changes are possible within the scope of the invention.

Claims (14)

A terminal device,
Acquisition means for acquiring from the base station apparatus information that associates the number of bits of uplink control information to be transmitted to the base station apparatus with the resource on which the uplink control information of the number of bits is to be transmitted;
a second number of bits of uplink control information to be transmitted to the base station apparatus, based on a first number of bits required for transmission of an acknowledgment accompanied by accompanying information about the reception status of user data from the base station apparatus; a specific means to identify;
transmitting means for transmitting uplink control information including the acknowledgment to the base station apparatus using the resource associated with the second number of bits;
A terminal device comprising: the acquisition means acquires from the base station apparatus designation information designating whether or not the accompanying information is transmitted and the contents of the accompanying information;
When the specifying information indicates that the accompanying information is not to be transmitted, the identifying means transmits the accompanying information assuming that the acknowledgment indicating only whether or not the user data has been successfully received is to be sent. When the designation information indicates, the first number of bits is specified based on the number of bits required to express the content of the accompanying information designated by the designation information.
The terminal device according to claim 1, characterized by: The specifying means determines the first number based on a value obtained by multiplying the number of codewords transmitted as the user data from the base station apparatus and to which the acknowledgment should be transmitted by the number of bits of one acknowledgment. specify the number of bits,
3. The terminal device according to claim 1 or 2, characterized by: The obtaining means receives the information in which a plurality of resources are individually associated with each of one or more values of the number of bits, and the predetermined information specifying which of the plurality of resources should be used. obtained from the station equipment,
The transmitting means transmits uplink control information including the acknowledgment to the base station using a resource designated by the predetermined information among the plurality of resources associated with the second number of bits. send to the device,
The terminal device according to any one of claims 1 to 3, characterized in that: further comprising decoding means for decoding the user data using an iterative decoding method that iteratively performs decoding of one codeword;
The acknowledgment with the accompanying information has a value indicating that the user data has failed to be received, and the iteration when the iterative decoding method determines the success of the reception when the user data is successfully received. A value indicating the number of times of
5. The terminal device according to any one of claims 1 to 4, characterized in that: further comprising measuring means for measuring radio quality when receiving the user data;
wherein the acknowledgment accompanied by the accompanying information further includes a value indicating the radio quality when indicating at least one of failure or success in receiving the user data;
The terminal device according to any one of claims 1 to 5, characterized in that: A base station device,
a notification means for notifying the terminal device of information that associates the number of bits of uplink control information to be received from the terminal device with the resource on which the uplink control information of the number of bits is to be transmitted;
a transmitting means for transmitting user data to the terminal device;
Receiving means for receiving an acknowledgment accompanied by accompanying information about the reception status of the user data in the terminal device, the bits required for transmitting uplink control information based on a first number of bits required for transmitting the acknowledgment receiving means for receiving the acknowledgment on the resource associated with a second number of bits identified as a number;
A base station device characterized by having: The notification means notifies the terminal device of designation information designating whether or not the accompanying information is to be transmitted and the content of the accompanying information;
If the designation information indicates that the accompanying information is not to be transmitted, the acknowledgment indicating only whether or not the user data has been successfully received is transmitted, and the designation information indicates that the accompanying information is to be transmitted. indicates, the first number of bits is specified based on the number of bits required to express the content of the accompanying information specified by the specified information.
The base station apparatus according to claim 7, characterized by: The first number of bits is specified based on a value obtained by multiplying the number of codewords to be transmitted as the user data to the terminal device and for which the acknowledgment is to be received by the number of bits of one acknowledgment. ,
9. The base station apparatus according to claim 7 or 8, characterized by: The notification means transmits the information in which a plurality of resources are individually associated with each of the plurality of values indicating the number of bits, and the predetermined information specifying which of the plurality of resources should be used, to the terminal device. to notify
The receiving means receives uplink control information including the acknowledgment in a resource designated by the predetermined information among the plurality of resources associated with the second number of bits.
The base station apparatus according to any one of claims 7 to 9, characterized by: A communication method performed by a terminal device,
Acquiring from the base station apparatus information that associates the number of bits of uplink control information to be transmitted to the base station apparatus with a resource on which the uplink control information of the number of bits is to be transmitted;
a second number of bits of uplink control information to be transmitted to the base station apparatus, based on a first number of bits required for transmission of an acknowledgment accompanied by accompanying information about the reception status of user data from the base station apparatus; to identify;
transmitting uplink control information including the acknowledgment to the base station apparatus using the resource associated with the second number of bits;
A communication method comprising: A communication method performed by a base station device,
Notifying the terminal device of information that associates the number of bits of uplink control information to be received from the terminal device with the resource on which the uplink control information of the number of bits is to be transmitted;
transmitting user data to the terminal device;
Receiving an acknowledgment with accompanying information about the reception status of the user data in the terminal device, wherein, for transmission of uplink control information based on a first number of bits required for transmission of the acknowledgment receiving the acknowledgment at the resource associated with a second number of bits identified as the number of bits required;
A communication method comprising: on the computer installed in the terminal device,
Acquiring from the base station apparatus information that associates the number of bits of uplink control information to be transmitted to the base station apparatus and the resource on which the uplink control information of the number of bits is to be transmitted;
a second number of bits of uplink control information to be transmitted to the base station apparatus, based on a first number of bits required for transmission of an acknowledgment accompanied by accompanying information about the reception status of user data from the base station apparatus; specify,
causing the base station apparatus to transmit uplink control information including the acknowledgment using the resource associated with the second number of bits;
program for. In the computer provided in the base station equipment,
Notifying the terminal device of information that associates the number of bits of uplink control information to be received from the terminal device with the resource on which the uplink control information of the number of bits is to be transmitted,
causing user data to be transmitted to the terminal device;
Receive an acknowledgment with accompanying information about the reception status of the user data in the terminal device, where the number of bits required to transmit uplink control information based on the first number of bits required to transmit the acknowledgment causing the acknowledgment to be received on the resource associated with the identified second number of bits;
program for.

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