JP7408596B2 - Terminal device, base station device, communication method, and program using extended acknowledgment - Google Patents

Description

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

The cellular communication standard developed by the 3rd Generation Partnership Project (3GPP) uses a mechanism that uses combined automatic repeat request (HARQ) to share information between the transmitting side and the receiving side as to whether or not the transmission and reception of wireless frames has been successful. There is. According to this mechanism, for example, when the terminal device successfully receives a radio frame transmitted from the base station device to the terminal device, the terminal device transmits an acknowledgment (ACK) associated with the radio frame to the base station device, If the wireless frame is not received normally, a negative acknowledgment (NACK) associated with the wireless frame is transmitted to the base station device. Then, upon receiving the NACK, the base station apparatus retransmits a radio frame containing data with the same content or a radio frame of another redundancy version generated based on the data. Thereby, the reliability of data transmission from the base station device to the terminal device can be improved. Further, in a similar manner, it is also possible to improve the reliability of data transmission from the terminal device to the base station device.

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

In ultra-reliable communication, it is assumed that an extremely low value is used as the target value of the error rate. In such a case, it is assumed that the device receiving the frames can normally receive almost all the frames. In such a case, it is assumed that most frames are received normally and no NACK is transmitted or received unless the number of times ACK/NACK is transmitted and received is extremely large. Therefore, for example, if a single NACK is sent and received due to instantaneous deterioration in communication quality, the second MCS, which has a lower communication rate than the first MCS that is appropriate for the actual communication environment, is used. This could be the case. Further, after the use of the second MCS is started, a huge number of radio frames need to be transmitted and received in order to determine that the first MCS suitable for the original communication environment should be used. As such, conventional HARQ mechanisms may not be able to adapt to the diversification of communication requirements.

The present invention provides advanced technology for automatic retransmission control such as HARQ.

A terminal device according to one aspect of the present invention includes an acquisition unit that acquires information indicating a resource set including a plurality of resources for transmitting uplink control information from a base station device, and receives user data from the base station device. and specifying means for specifying first information indicating whether reception of the user data was successful or unsuccessful, and second information indicating accompanying information regarding the reception status of the user data; Among them, a resource associated with the combination of the first information and the second information, and a value to be transmitted as an acknowledgment with the resource, the first information and the second information and a transmission means for transmitting uplink control information including the selected value in the selected resource to the base station apparatus, Any one of the resources is selected, and the information indicated by the selection of the resource and the information indicated by the value transmitted in the resource are individually the first information and the first information. The combination of the first information and the second information is shown by not showing either of the two pieces of information and treating each as a whole .

A base station device according to one aspect of the present invention includes a notification unit that notifies the terminal device of information indicating a resource set including a plurality of resources for the terminal device to transmit uplink control information, and a a transmitting means for transmitting data; a receiving means for receiving uplink control information from the terminal device in any one of a plurality of resources included in the set of resources; and a receiving means for receiving the uplink control information from the terminal device. First information indicating success or failure of reception of the user data in the terminal device based on a resource and a value transmitted as an acknowledgment in the resource; and additional information indicating a reception status of the user data. 2 , wherein any one of the resources is selected, the information indicated by the selection of the resource and the value transmitted in the resource. Each piece of information alone does not represent either the first information or the second information, but represents a combination of the first information and the second information by being treated as a unit.

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

1 is a diagram illustrating a configuration example of a wireless communication system. It is a diagram showing an example of the hardware configuration of a base station device and a terminal device. FIG. 2 is a diagram showing 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. FIG. 2 is a diagram outlining the flow of processing executed in the wireless communication system.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the claimed invention, and not all combinations of features described in the embodiments are essential to the invention. Two or more features among the plurality of features described in the embodiments may be arbitrarily combined. In addition, the same or similar configurations are given the same reference numerals, and duplicate explanations will be omitted.

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

Note that in communication of user data, composite automatic repeat request (HARQ) may be used. For example, when the terminal device 102 receives downlink user data from the base station device 101, it transmits an acknowledgment to the base station device 101 indicating the result of the reception. Note that the base station device 101 may transmit an HARQ acknowledgment regarding user data transmitted from the terminal device 102. Acknowledgments generally include an acknowledgment (ACK) that is sent when user data is successfully received, and a negative acknowledgment (NACK) that is sent when 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 it is determined that there is no error in the decoding result by a CRC (Cyclic Redundancy Check) on the decoding result, It is determined that the user data has been successfully received. On the other hand, if the decoding result does not contain any errors based on the CRC, it is determined that the reception of the user data has failed.

In one example, the error correction code may be an LDPC (Low Density Parity Check) code or a polar code. A fixed size of user data is encoded by an error correction code to generate one codeword. Decoding may be performed on a codeword basis. Further, decoding may be performed using an iterative decoding method in which decoding processing for one codeword is repeatedly performed (for example, using soft decision values). In this case, it can be determined using the CRC whether the decoding result obtained during the repetition of the decoding process contains an error. In this case, if the decoding result obtained midway does not contain any errors, the repetition of the decoding process may be terminated.

The terminal device 102 transmits uplink control information (UCI) including a HARQ acknowledgment response. At this time, the terminal device 102 transmits an acknowledgment for each codeword. The UCI is transmitted, for example, by a physical uplink control channel (PUCCH). Therefore, when a plurality of codewords are transmitted at the same time due to carrier aggregation, for example, a plurality of acknowledgment responses may also be transmitted at the same time. 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 bits of the UCI may be variable.

At this time, the base station device 101 transmits to the terminal device 102 information that associates the number of bits to be transmitted in the UCI with one or more resources to which the UCI is to be transmitted. When the terminal device 102 specifies the number of bits of the UCI to be transmitted, it specifies a resource corresponding to the number of bits based on that information, and transmits the UCI using that resource. For example, the base station apparatus 101 uses the first resource when the number of UCI bits is less than or equal to a first predetermined number of bits, and the base station apparatus 101 uses the first resource when the number of UCI bits is greater than the first predetermined number of bits and less than or equal to the second predetermined number of bits. Information relating the resource and the number of bits, such as the second resource, etc., is transmitted. Then, for example, in a situation where the terminal device 102 should transmit a UCI that is greater than the first predetermined number of bits and less than or equal to the second predetermined number of bits, the terminal device 102 transmits the UCI using the second resource. Note that the base station device 101 can know in advance the number of bits of the UCI to be transmitted by the terminal device 102 based on, for example, the number of code words transmitted in parallel. Resources to be sent can be known in advance. Note that the UCI may include, for example, information (CSI, Channel State Information) indicating the state of the downlink channel, and when specifying the number of bits of the UCI, it is necessary to specify not only the number of bits required for transmitting an acknowledgment, but also the number of bits required for transmitting an acknowledgment. All of the information to be transmitted, such as CSI, is considered.

Note that there may be multiple resources associated with each number of bits, and in this case, the base station device 101 may notify the terminal device 102 of information specifying which of the multiple resources should be used. . That is, the base station apparatus 101 uses resources 0 to resource N1-1 when the number of bits of the UCI is less than or equal to the first predetermined number of bits, and when the number of bits of the UCI is greater than the first predetermined number of bits and less than or equal to the second predetermined number of bits. Information that associates a set of resources with the number of bits, such as resource N1 to resource N2-1, . . . in the case of , is transmitted. Then, the base station apparatus 101 determines that the number of bits of the UCI is greater than the first predetermined number of bits and less than or equal to the second predetermined number of bits, and that the base station apparatus 101 should use resource N1+3 (the fourth resource in the set of resources). If it is determined that, for example, the terminal device 102 can be notified to use the "fourth" resource. As a result, the terminal device 102 identifies resources N1 to 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 less than or equal to the second predetermined number of bits, and further specifies the resources N1 to N2-1. It is possible to specify the resource N1+3, which is the fourth resource among the resources, and transmit the UCI using that resource.

Base station apparatus 101 may be configured to determine a modulation and coding scheme (MCS) to be used in a wireless link based on HARQ acknowledgments and retransmissions. For example, a target frame error rate is set based on the quality of service (for example, indicated by QCI (QoS Class Indicator), etc.) 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 (number of NACK transmissions) with respect to the number of uplink user data receptions. 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 is necessary to use a huge number of codes in order to determine whether or not the MCS being used is appropriate based only on the binary acknowledgment consisting of ACK and NACK. Words need to 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 this embodiment, in view of such circumstances, the HARQ confirmation response is advanced, thereby making it possible to perform the settings of MCS used in the wireless link with high precision. In this embodiment, for example, the acknowledgment is configured so that information can be expressed in three or more stages instead of in the binary form of ACK and NACK.

For example, if an iterative decoding method is used in which one codeword is repeatedly decoded, and the codeword is successfully decoded (that is, user data is successfully received), the iterative decoding method The number of successful iterations can be sent in the acknowledgment. That is, when an ACK is sent in the confirmation response, the confirmation response is configured such that the number of repetitions for successful decoding is transmitted as accompanying information accompanying successful reception of user data. For example, if the number of repetitions of the process until successful decoding is small (for example, once), the wireless quality can be evaluated as being excessively good. On the other hand, if the number of iterations until decoding is successful is the maximum number of iterations set in advance, the decoding of the codeword is successful, but if the wireless quality deteriorates even a little. It can be evaluated that there is a certain probability that decoding will fail. For this reason, the base station apparatus 101 performs a check based on the acknowledgment accompanied by the accompanying information so that the number of repetitions upon successful decoding approaches a predetermined number of times (for example, more than one time and less than the maximum number of times). , can determine the MCS to use. Note that the number of repetitions may be expressed with various granularities, and the more the number of possible values of the accompanying information is increased, the finer the granularity indicating the number of repetitions can be set.

In one example, the acknowledgment accompanied by the accompanying information is, for example, "1" if the codeword was successfully decoded in one decoding process, and "2" if the codeword was successfully decoded in 2 to 9 decoding processes. , 10 times to the maximum number of iterations, "3" indicates successful decoding, and "4" indicates unsuccessful decoding. In addition, the confirmation response with accompanying information is, for example, "1" if the codeword was successfully decoded in one decoding process, "2" if the codeword was successfully decoded in two or three decoding processes, ``3'' if decryption was successful after 4 to 5 decryption processes, ``4'' if decryption was successful after 6 to 7 decryption processes, and ``4'' if decryption was successful after 8 to 9 decryption processes. "5" if decoding was successful after 10 to 11 decoding processes, "7" if decoding was successful after 12 to the maximum number of iterations, and "7" if decoding was unsuccessful. In some cases, it may be expressed in eight values, such as "0". Note that these are just examples, and the relationship between the bit string and the number of decodings may be different from the above example. For example, an acknowledgment format that can provide more detailed information than the above example may be used. It's okay to be hit. Further, in the above example, a case has been described in which the acknowledgment accompanied by the accompanying information can take on a power of two values, but the number of possible values does not have to be a power of two.

Also, when receiving user data, the radio quality such as SINR (Signal to Interference plus Noise Ratio) is measured using a known signal such as DMRS (Demodulation Reference Signal), and the radio quality of the measurement result is indicated. An acknowledgment including the value as accompanying information may be sent and received. Note that 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 the wireless quality. Note that this wireless quality may be transmitted and received as information accompanying an acknowledgment when the codeword demodulation is successful, or as information accompanying a negative response when the codeword demodulation fails. good. In other words, even if decoding is successful, whether the wireless quality is insufficient, sufficient, or excessive is transmitted and received as accompanying information, so that the communication status can be determined. It becomes possible to set MCS suitable for. Furthermore, when decoding fails, it is possible to appropriately select which MCS to use depending on the wireless quality. That is, when side information is not used, even if successful decoding requires changing the MCS significantly (i.e., selecting an MCS that is more resistant to interference and noise), the By changing the MCS, decoding errors may continue. On the other hand, by transmitting and receiving acknowledgments with accompanying information, it becomes possible to set an appropriate MCS at one time.

Note that this wireless quality information and the above-described information on the number of repetitions may be used in combination. For example, an acknowledgment with accompanying information may be configured such that the number of repetitions is notified if decoding is successful, and the radio quality is notified if decoding fails. Further, in this case, when decoding is successful, the wireless quality may be notified in addition to the number of repetitions.

In this embodiment, information is provided as to which resource is to be used out of a resource set that includes a plurality of resources to be used when transmitting uplink control information. For example, the UCI includes an acknowledgment indicating whether the user data was successfully received or failed, but in this embodiment, depending on the combination of the resource to which the UCI is transmitted and the value transmitted as the acknowledgment, Information indicating whether or not the user data was successfully received (first information) and accompanying information (second information) indicating the reception status of the user data (for example, the number of repetitions of the decoding process and wireless quality as described above) ) expresses the combination with For example, if two resources are prepared and the first resource sends a UCI with an acknowledgment value of "0", it indicates that the reception of user data has failed, and the second resource If a UCI with a response value of "0" is transmitted, it may indicate that user data has been successfully received with one iteration of the decoding process. Furthermore, if a UCI with an acknowledgment value of "1" is transmitted in the first resource, it indicates that the user data has been successfully received after the decoding process has been repeated 2 to 9 times, and the second resource If a UCI with an acknowledgment value of "1" is transmitted in a resource, it may indicate that user data has been successfully received when the number of iterations of the decoding process is 10 to the maximum number of iterations. In this way, the combination of the success or failure of reception of user data and the reception status can be indicated by the relationship between the value transmitted as an acknowledgment and the resources used. Note that if the number of usable resources is N, then the number of types of information that can be expressed using this method is 2N. In this way, by increasing the number of available resources ("N"), more detailed information can be conveyed.

Note that when multiple acknowledgments are sent, all the second information corresponding to each of the multiple acknowledgments may be sent, for example, the highest/least number of repetitions, the lowest/highest, etc. Only the second information regarding some codewords, such as the radio quality, the number of repetitions, or the average value or median value of the radio quality, may be transmitted.

The base station apparatus 101 of this embodiment notifies the terminal apparatus 102 of a resource set including a plurality of resources for the terminal apparatus 102 to transmit UCI for the above-described processing. Note that the combination of each of the plurality of resources at this time and the value transmitted as an acknowledgment in that resource is the first information indicating the success or failure of reception of the user data and the second information indicating the reception status of the user data. associated with the combination of information. This association rule may be shared between the base station device 101 and the terminal device 102 in advance (for example, by being defined by a standard), or the base station device 101 may determine the association. The terminal device 102 may also be notified.

Then, the base station device 101 transmits user data to the terminal device 102. When the terminal device 102 receives user data from the base station device 101, it specifies first information indicating whether the user data has been successfully received and second information indicating the reception status of the user data. Then, the terminal device 102 selects a resource associated with the combination of the first information and the second information and a value to be transmitted as an acknowledgment for the resource from among the set of notified resources. , a value associated with the combination of the first information and the second information. That is, the terminal device 102 identifies a combination of a resource to which the UCI is transmitted and a value to be transmitted as an acknowledgment in that resource, which represents the combination of the first information and the second information. Then, the terminal device 102 transmits the UCI including the selected value as an acknowledgment response to the base station device 101 in the selected resource. The base station device 101 waits for the UCI to be received on the plurality of resources notified to the terminal device 102, and when the UCI is received on any of the resources, the base station device 101 receives the UCI from the resource and the value transmitted as an acknowledgment for the resource. A combination of the above-mentioned first value and second value is specified based on the above. In this way, it becomes possible for the terminal device 102 to notify the base station device 101 not only whether or not the user data has been successfully received, but also the reception status of the user data.

Note that the base station device 101 notifies the terminal device 102 of third information that associates the first set of resources with each value of the number of bits required for UCI transmission, and then , out of the first set of resources, fourth information indicating a second set of resources including a plurality of resources for the terminal device 102 to transmit uplink control information is notified to the terminal device 102. You can. In this case, the terminal device 102 identifies, for example, a first set of resources associated with the number of bits of the UCI that indicates only whether the reception of user data was successful or unsuccessful (without using accompanying information). . Then, the terminal device 102 selects first information indicating success or failure of reception of the user data and second information indicating the reception status of the user data from the second set included in the first set. Select the resource corresponding to the combination and the value to be transmitted on that resource. Note that the above-mentioned third information is transmitted by a broadcast signal such as SIB (System Information Block), and the fourth information is transmitted individually by downlink control information (DCI), RRC (radio resource control) signaling, etc. can be sent. Note that the first set of resources corresponding to the number of bits required for transmitting the UCI does not need to be defined, and the base station apparatus 101 directly specifies a plurality of resources for transmitting the UCI and transmits the UCI to the terminal apparatus 102. You may also notify the.

Note that the plurality of resources for transmitting the UCI are individually set for each terminal device, and in one example, the resources specified for the plurality of terminal devices can be set so that they do not overlap. Note that some resources may be set to overlap.

Note that when the base station apparatus 101 does not use the accompanying information, the base station apparatus 101 can notify the terminal apparatus 102 of information specifying only one resource for transmitting the UCI, for example, as in the past. Since the terminal device 102 is notified of only one resource, it can recognize that it should send only the conventional acknowledgment, and can send the UCI without accompanying information. Note that the base station apparatus 101 determines whether to use an acknowledgment with accompanying information or an acknowledgment without accompanying information based on, for example, the service quality or the value of the frame error rate of the corresponding target. can be determined. For example, when a communication service that requires ultra-high reliability is provided, an acknowledgment with accompanying information is used when the target frame error rate is lower than a predetermined value, and in other cases, an acknowledgment with accompanying information is used. It is also possible to use an acknowledgment without . Further, for example, the lower the frame error rate of the target, the more the amount of information in the acknowledgment accompanied by the accompanying information can be increased (for example, the number of bits or the number of possible values can be increased). By increasing the amount of information in the acknowledgment with accompanying information, the reception status will be expressed in more detail, so it is possible to perform detailed and appropriate MCS settings, etc. based on that detailed information. becomes. Note that here, a case will be described in which the base station device 101 transmits user data to the terminal device 102, and the terminal device 102 transmits an acknowledgment (including accompanying information as necessary) to the base station device 101. , but not limited to this. That is, the sophistication of acknowledgment as described above can be used in a system where a detailed report of the reception status is useful, such as control of a wireless link based on the success or failure of reception such as HARQ.

Note that if a resource for transmitting user data on the uplink is allocated, the terminal device 102 may transmit information indicating the first information and second information described above using that resource. Can be done. That is, an acknowledgment accompanied by accompanying information may be multiplexed with uplink user data as necessary and transmitted together with the user data.

As described above, in this embodiment, by improving the HARQ acknowledgment, it is possible for the terminal device 102 to 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 the success or failure of reception. Therefore, it is possible to configure a wireless link so that an appropriate MCS is used based on a small number of acknowledgment responses. Note that such advanced acknowledgment can be used in any system that uses acknowledgment such as HARQ or ARQ, and can also be applied to acknowledgment for user data transmitted from the terminal device 102. Further, any wireless communication device other than the base station device 101 and the terminal device 102 can use this method.

(Device configuration)
Next, an example of the hardware configuration of the base station device 101 and the terminal device 102 that execute the above-described processing will be described using FIG. 2. In one example, the base station device 101 and the terminal device 102 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 that includes one or more processing circuits such as a general-purpose CPU (central processing unit) or an ASIC (application-specific integrated circuit), and is stored in a ROM 202 or a storage device 204. By reading and executing the program, the overall processing of the base station device 101 and the terminal device 102 and each of the above-mentioned processes are executed. The ROM 202 is a read-only memory that stores information such as programs and various parameters related to processing executed by the base station device 101 and the terminal device 102. The RAM 203 is a random access memory that functions as a work space when the processor 201 executes a program and also stores temporary information. The storage device 204 is configured by, for example, a removable external storage device. The communication circuit 205 is configured by, for example, a circuit for 5G wireless communication. Note that although one communication circuit 205 is illustrated in FIG. 2, the base station device 101 and the terminal device 102 may have a plurality of communication circuits. For example, the base station device 101 and the terminal device 102 may have separate communication circuits 205 for each of a plurality of usable frequency bands. Furthermore, the base station device 101 and the terminal device 102 may have a common communication circuit 205 for at least part of a plurality of frequency bands. Further, for example, the terminal device 102 may include not only a communication circuit 205 for cellular communication but also a communication circuit 205 compatible with other wireless communication standards such as wireless LAN.

FIG. 3 is a diagram showing an example of the functional configuration of the terminal device 102. The terminal device 102 has, as its functions, a resource information acquisition section 301, a user data reception processing section 302, a response generation processing section 303, and a response transmission section 304, for example. Note that FIG. 3 only shows functions particularly related to this embodiment, and various other functions that the terminal device 102 may have are not shown. For example, terminal device 102 naturally has other functions that terminal devices in cellular communication systems typically have. Further, the functional blocks in FIG. 3 are schematically shown, and each functional block may be realized by being integrated or may be further subdivided. Further, 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, for example, by the processor existing inside the communication circuit 205 executing a predetermined It may be realized by executing software.

The resource information acquisition unit 301 acquires from the base station device 101 information about a resource set including a plurality of resources for transmitting UCI and including an acknowledgment to be transmitted when user data is received. Note that the resource information acquisition unit 301 may, for example, acquire a set of resources separately for each number of bits of the UCI to be transmitted, as in the conventional manner. In this case, the resource information acquisition unit 301 acquires in advance a first set of resources for each number of UCI bits (for example, by a broadcast signal such as SIB transmitted from the base station device 101), and Information specifying a second set specifying a plurality of resources can be acquired from among the sets. Information specifying the second set can be notified by a control signal (PDCCH, physical downlink control channel) transmitted when transmitting user data, for example, by DCI. In this case, the multiple resources specified by the second set are treated as multiple resources for UCI transmission. Note that, regardless of the number of bits of the UCI, a set of resources (including a large number of resources) is defined in advance as resource candidates for UCI transmission, and the base station apparatus 101 determines which of them to use. The notification may be sent to the terminal device 102 from there.

If some of the resource candidates for UCI transmission are designated as resources that can be used to actually transmit the UCI, for example, the resource information acquisition unit 301 can uniquely identify each resource candidate. You can get a list of unique identification numbers. Further, if a list of resource candidates is defined in advance, the resource to be used may be identified by a number indicating the order in the list. In one example, if there are 16 resource candidates, the resource to be used can be specified using numbers 0 to 15 indicating the order. For example, the information "0, 7" may specify the resource candidate listed first on the list and the resource candidate listed eighth on the list as the resources to be used. Note that the order of the information may have meaning. For example, when the information "0, 7" is notified, "0" is sent as an acknowledgment in the first resource, indicating that the reception of user data has failed, and the first resource In the 8th resource, an acknowledgment “1” is sent as an acknowledgment, indicating that the radio quality is excessively good for the MCS in use, and an acknowledgment “0” or “1” is sent in the eighth resource. can indicate that the wireless quality is a value suitable for MCS or that the wireless quality is low. On the other hand, when the information "7, 0" is notified, "0" is sent as an acknowledgment in the 8th resource, indicating that the reception of user data has failed, and the 8th resource An acknowledgment “1” is sent in the first resource to indicate that the radio quality is excessively good for the MCS in use, and an acknowledgment “0” or “1” is sent in the first resource. can indicate that the wireless quality is a value suitable for MCS or that the wireless quality is low.

In addition, by specifying multiple resources consecutively listed in the resource candidate list using the first resource and the number of usable resources, the resources that can be used for UCI transmission are specified. You can. For example, if there are 16 resource candidates, using the numbers 0 to 15 that indicate their order, the information "3, 2" selects two from the fourth resource, that is, the fourth resource and the fifth resource. Resources may be designated as available for transmitting UCI. Further, resources that can be used for UCI transmission may be specified by the first number and the last number of consecutive resources. For example, the information "3, 8" may specify the fourth resource to the ninth resource as resources that can be used for UCI transmission. Also in this case, information may be given to the order.

Note that if only one resource that can be used for transmitting the UCI is specified, an acknowledgment without accompanying information will be transmitted as in the past.

The user data reception processing unit 302 executes reception processing of user data transmitted from the base station device 101. Note that the reception processing executed by the user data reception processing unit 302 is similar to conventional user data reception processing, but at this time, for example, when the iterative decoding method is used, decoding is performed at the time when decoding is successful. It is configured to measure the number of processing repetitions and radio quality based on DMRS, and to hold and output the results.

The response generation processing unit 303 first receives first information indicating whether the user data reception processing unit 302 succeeded or failed in receiving the user data, and the reception status (for example, the number of repetitions of decoding processing and the measured value of wireless quality). ) is specified. Then, a second combination of a UCI transmission resource and a value to be transmitted as an acknowledgment, which is associated with the first combination of the first information and the second information, is specified. Then, the response generation processing unit 303 generates a UCI that includes the value of the acknowledgment corresponding to the specified second combination.

The response transmitting unit 304 transmits the UCI generated by the response generation processing unit 303 to the base station device 101 using the resource for transmitting the UCI corresponding to the second combination identified as described above. .

FIG. 4 is a diagram showing an example of the functional configuration of the base station device 101. The base station apparatus 101 has, for example, a resource information notification section 401, a user data transmission section 402, a response reception section 403, and an acknowledgment analysis section 404 as its functions. Note that FIG. 4 only shows functions particularly related to this embodiment, and various other functions that the base station apparatus 101 may have are not shown. For example, the base station device 101 naturally has other functions that a base station device in a cellular communication system generally has. Further, the functional blocks in FIG. 4 are schematically shown, and each functional block may be realized by being integrated or may be further subdivided. Further, 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, for example, by a processor existing inside the communication circuit 205 executing a predetermined program. It may be realized by executing software.

The resource information notification unit 401 notifies the terminal device 102 of information on a resource set including a plurality of resources that can be used by the terminal device 102 to transmit a UCI. The method of notifying this set of resources has been described in the explanation regarding the resource information acquisition unit 301 of the terminal device 102, so the explanation will be omitted here. User data transmitting section 402 transmits user data to terminal device 102. This transmission of user data is performed in a conventional manner and will not be described in detail here. The response receiving unit 403 receives the UCI including the confirmation response for the user data from the terminal device 102. For example, the response receiving unit 403 waits for receiving the UCI from the terminal device 102 in each of a plurality of resources that can be used for transmitting the UCI notified to the terminal device 102 by the resource information notifying unit 401, and receives the UCI from the terminal device 102. Receive UCI on any of the resources. The acknowledgment analysis unit 404 identifies in which resource the UCI received by the response receiving unit 403 was received, and the value received as the acknowledgment for that UCI. Then, based on the combination of the resource for which the UCI was received and the value received as the acknowledgment, the acknowledgment analysis unit 404 generates first information indicating whether the reception of the user data was successful or failed, and the A combination of the user data and second information indicating the reception status (as accompanying information added to the success or failure of reception) is specified.

By using the above-described configuration, the terminal device 102 can combine the first information indicating whether the reception of the user data has been successful or unsuccessful with the second information indicating the accompanying information regarding the reception status of the user data. is indicated by the combination of the resource used to transmit the UCI and the value transmitted as an acknowledgment using that resource. Then, the base station device 101 can identify the combination of the above-mentioned first information and second information based on the combination of the resource that received the UCI and the value that was received as an acknowledgment with that resource. According to this, the base station apparatus 101 is notified not only of the success or failure of reception of user data but also of the reception status at that time (for example, the number of repetitions of decoding processing and the measured value of radio quality), so that a small number of acknowledgment responses are required. This allows the base station device 101 to quickly and appropriately perform control such as determining MCS.

(Processing flow)
Next, an example of the flow of processing executed by the base station device 101 and the terminal device 102 according to the present embodiment will be outlined using FIG. 5. Note that this is just an example, and the base station device 101 and the terminal device 102 may perform various types of processing as exemplified above.

In this process, first, the base station apparatus 101 selects a plurality of resource candidates that are associated with the number of bits of the UCI and should be used when transmitting the UCI of that number of bits, for example, via a broadcast SIB or the like. The information shown is transmitted to the terminal device 102 (S501). Note that this information may be individually notified to the terminal device 102 using, for example, an RRC message. Note that the process of S501 may be omitted in cases where resource candidates that can be used for transmitting the UCI are determined in advance, or in cases where a set of resources for each number of bits of the UCI is not defined. The base station apparatus 101 transmits to the terminal apparatus 102 information specifying a plurality of resources that the terminal apparatus 102 can actually use for transmitting UCI (S502). After that, the base station device 101 transmits user data to the terminal device 102 (S503). Note that information identifying a plurality of resources that can be used by the terminal device 102 for transmitting UCI is individually transmitted to the terminal device 102 using an RRC message, DCI, or the like. Note that when the notification is performed using the DCI, the information in S502 is transmitted using the DCI transmitted on the PDCCH that is also transmitted when transmitting the user data in S503. Therefore, the processes of S502 and S503 are performed by one transmission of user data. Note that the base station apparatus 101 may notify the resources that can be used for transmitting the UCI each time the user data is transmitted, or, for example, the base station apparatus 101 may notify the resources that can be used for transmitting the UCI once for the transmission of a plurality of user data. It is also possible to notify the resource.

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 the reception of the user data (decoding of the code word) was successful or not, and when transmitting an acknowledgment accompanied by accompanying information, the terminal device 102 determines whether or not the reception of the user data (decoding of the code word) has been successful. Then, the radio quality and the number of repetitions of decoding processing using the iterative decoding method are determined. Then, the terminal device 102 selects a resource from among the plurality of resources that can be used for transmitting the UCI identified in S502 according to the determined reception status result (information indicating success or failure of reception of user data and accompanying information). The resource to be used is identified, and the value to be transmitted as an acknowledgment in that resource is identified (S505). Then, the terminal device 102 transmits a UCI having the specified value as an acknowledgment value to the base station device 101 in the specified resource (S506).

The base station device 101 waits for an acknowledgment to arrive at a plurality of resources that can be used to transmit the UCI, and receives the UCI at any one of the resources. Then, the base station device 101 determines whether the terminal device 102 succeeded or failed in receiving the user data based on which resource received the UCI and the value included in the UCI as an acknowledgment value. , and the accompanying information (the number of repetitions of the decoding process, the radio quality of the received signal, etc.) obtained when receiving the user data (S507). The base station apparatus 101 can perform, for example, MCS adjustment based on this identified information.

In this way, in this embodiment, by configuring the acknowledgment with accompanying information, it is possible to check not only the success or failure of reception of user data, but also the situation in which reception of user data was successful/failed. The base station device 101 can now recognize whether the This allows the base station device 101 to appropriately control the wireless link with the terminal device 102 in various situations.

The invention is not limited to the above-described embodiments, and various modifications and changes can be made within the scope of the invention.

Claims (14)

A terminal device,
acquisition means for acquiring information indicating a resource set including a plurality of resources for transmitting uplink control information from a base station device;
Receive user data from the base station device, and identify first information indicating whether reception of the user data was successful or unsuccessful, and second information indicating accompanying information regarding the reception status of the user data. specific means,
from the set of resources, a resource associated with a combination of the first information and the second information; and a value to be sent as an acknowledgment with the resource, the value being associated with the combination of the first information and the second information; a selection means for selecting a value associated with the combination with the second information;
Transmitting means for transmitting uplink control information including the selected value in the selected resource to the base station device;
has
Any one of the resources is selected, and the information indicated by the selection of the resource and the information indicated by the value transmitted in the resource are individually the first information and the first information. Indicating a combination of the first information and the second information by not showing any of the second information and treating each as a whole ;
A terminal device characterized by: The acquisition means includes third information in which a first set of resources is associated with each number of bits of the uplink control information; and fourth information indicating a second set of resources including a plurality of resources to be used for transmission of the combination with the information of No. 2 from the base station device,
The selection means selects one of the second sets included in the first set associated with the number of bits of the uplink control information when only indicating whether reception of the user data was successful or unsuccessful. , selecting a resource associated with the combination of the first information and the second information and a value to be sent as an acknowledgment on the resource;
The terminal device according to claim 1, characterized in that: The third information is transmitted by broadcast from the base station device, and the fourth information is individually transmitted to the terminal device.
The terminal device according to claim 2, characterized in that: The fourth information is transmitted by downlink control information,
The terminal device according to claim 2 or 3, characterized in that: further comprising decoding means for decoding the user data using an iterative decoding method for repeatedly decoding one code word;
The combination of the first information and the second information determines whether the user data has failed to be received, and if the user data has been successfully received, the iterative decoding method determines the success of the reception. indicating either the number of iterations or
The terminal device according to any one of claims 1 to 4. further comprising measurement means for measuring radio quality when receiving the user data,
The combination of the first information and the second information indicates a combination of at least one of failure and success of reception of the user data and a value indicating the radio quality.
The terminal device according to any one of claims 1 to 5. A base station device,
Notifying means for notifying the terminal device of information indicating a resource set including a plurality of resources for the terminal device to transmit uplink control information;
Transmitting means for transmitting user data to the terminal device;
Receiving means for receiving uplink control information from the terminal device in any one of the plurality of resources included in the resource set;
First information indicating success or failure of reception of the user data in the terminal device based on the resource that received the uplink control information and the value transmitted as an acknowledgment in the resource; and specifying means for specifying a combination with second information indicating accompanying information regarding the reception status ,
Any one of the resources is selected, and the information indicated by the selection of the resource and the information indicated by the value transmitted in the resource are individually the first information and the second information. Indicates a combination of the first information and the second information by not indicating any of the information and treating each as a unit;
A base station device characterized by: The notification means includes third information that associates a first set of resources with each number of bits of the uplink control information; and fourth information indicating a second set of resources including a plurality of resources to be used for transmission of the combination with the information of No. 2 to the terminal device.
The base station device according to claim 7, characterized in that: The notification means transmits the third information by broadcast, and individually transmits the fourth information to the terminal device.
The base station device according to claim 8, characterized in that: The notification means transmits the fourth information using downlink control information.
The base station device according to claim 8 or 9, characterized in that: A communication method performed by a terminal device, the method comprising:
obtaining from a base station device information indicating a resource set including a plurality of resources for transmitting uplink control information;
Receive user data from the base station device, and identify first information indicating whether reception of the user data was successful or unsuccessful, and second information indicating accompanying information regarding the reception status of the user data. And,
from the set of resources, a resource associated with a combination of the first information and the second information; and a value to be sent as an acknowledgment with the resource, the value being associated with the combination of the first information and the second information; selecting a value associated with the combination with the second information;
transmitting uplink control information including the selected value in the selected resource to the base station device;
has
Any one of the resources is selected, and the information indicated by the selection of the resource and the information indicated by the value transmitted in the resource are individually the first information and the first information. Indicating a combination of the first information and the second information by not showing any of the second information and treating each as a whole ;
A communication method characterized by: A communication method executed by a base station device, comprising:
Notifying the terminal device of information indicating a resource set including a plurality of resources for the terminal device to transmit uplink control information;
transmitting user data to the terminal device;
receiving uplink control information from the terminal device in any one of the plurality of resources included in the resource set;
First information indicating success or failure of reception of the user data in the terminal device based on the resource that received the uplink control information and the value transmitted as an acknowledgment in the resource; identifying a combination with second information indicating accompanying information regarding the reception status ;
Any one of the resources is selected, and the information indicated by the selection of the resource and the information indicated by the value transmitted in the resource are individually the first information and the second information. Indicates a combination of the first information and the second information by not indicating any of the information and treating each as a unit;
A communication method characterized by: In the computer equipped with the terminal device,
obtaining information indicating a resource set including a plurality of resources for transmitting uplink control information from a base station device;
Receive user data from the base station device, and specify first information indicating whether reception of the user data was successful or unsuccessful, and second information indicating accompanying information regarding the reception status of the user data. ,
from the set of resources, a resource associated with a combination of the first information and the second information; and a value to be sent as an acknowledgment with the resource, the value being associated with the combination of the first information and the second information; and a value associated with the combination with the second information,
transmitting uplink control information including the selected value in the selected resource to the base station device;
It is a program for
Any one of the resources is selected, and the information indicated by the selection of the resource and the information indicated by the value transmitted in the resource are individually the first information and the first information. Indicating a combination of the first information and the second information by not showing any of the second information and treating each as a whole ;
A program characterized by: In the computer equipped with the base station equipment,
Notifying the terminal device of information indicating a resource set including a plurality of resources for the terminal device to transmit uplink control information;
causing the terminal device to transmit user data;
receiving uplink control information from the terminal device in any one of the plurality of resources included in the resource set;
First information indicating success or failure of reception of the user data in the terminal device based on the resource that received the uplink control information and the value transmitted as an acknowledgment in the resource; A program for specifying a combination with second information indicating accompanying information regarding reception status ,
Any one of the resources is selected, and the information indicated by the selection of the resource and the information indicated by the value transmitted in the resource are individually the first information and the second information. Indicates a combination of the first information and the second information by not indicating any of the information and treating each as a unit;
program.

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