Terminal, base-station device, control method, and program for efficient communication using multiple component carriers

Abstract

To perform communication using a plurality of component carriers in an appropriate configuration according to processing capability in a terminal.SOLUTION: For each combination of component carriers (CCs) used in the dual connectivity or the carrier aggregation, information indicating a combination of numbers of layers of Multi-InputMulti-Output (MIMOs) in each of a plurality of CCs usable by the terminal, and information for enabling the terminal to receive signals of the plurality of CCs with predetermined qualities when the MIMOs of the numbers of layers indicated by the combination are used in each of the plurality of CCs, terminal, and information on a capability requirement including at least one of a reception timing difference and a reception power difference to be satisfied by a reception signal in terminal for each of the plurality of CCs.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present invention relates to a technique for effectively utilizing a plurality of component carriers in a cellular communication system. [Background technology]

[0002] The cellular communication standard of the Third Generation Partnership Project (3GPP (registered trademark)) specifies technologies for communication using multiple component carriers (CCs, carrier waves), known as dual connectivity (DC) and carrier aggregation (CA). It is expected that communication performance using such multiple CCs will be significantly degraded if the difference in received power between the CCs is large, particularly when a single communication circuit in a terminal device processes communication for the multiple CCs. Patent Document 1 indicates that the degradation of communication performance is significant when a single communication circuit is used in a terminal device, but that a relatively large difference in received power between the two CCs is tolerable when two communication circuits are used. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-117931 Summary of the Invention [Problem to be solved by the invention]

[0004] As communications via each CC become more sophisticated, it is expected that the quality of communications using multiple CCs will be significantly degraded even if the terminal device simply has two communication circuits. Also, even if the terminal device has only one communication circuit, it is expected that the improvement in the reception performance of the terminal device will enable it to perform sufficiently high-quality reception processing of signals via multiple CCs with large transmission power differences. [Means for solving the problem]

[0005] The present invention provides a technique that enables communication using multiple component carriers in an appropriate configuration according to the processing capacity of a terminal device.

[0006] A terminal device according to one aspect of the present invention has a notification means for notifying a base station device to which it is connected of capability information of the terminal device, the capability information including, for each combination of component carriers (CCs) used in dual connectivity or carrier aggregation, information indicating a combination of the number of layers of Multi-Input Multi-Output (MIMO) for each of multiple CCs that the terminal device can use in dual connectivity or carrier aggregation, and information on performance requirements including at least one of a reception timing difference and a reception power difference that the received signal at the terminal device must satisfy for each of the multiple CCs, so that the terminal device can receive signals of the multiple CCs with a predetermined quality when MIMO with the number of layers indicated by the combination is used for each of the multiple CCs; and a control means for receiving from the base station device control information including information on the number of layers of MIMO used in the multiple CCs, and controlling reception processing of signals in the multiple CCs based on the control information.

[0007] A base station device according to one aspect of the present invention has a receiving means for receiving from a connected terminal device capability information, the capability information including, for each combination of component carriers (CCs) used in dual connectivity or carrier aggregation, information indicating a combination of the number of multi-input multi-output (MIMO) layers in each of a plurality of CCs that the terminal device can use, for each combination of CCs used in dual connectivity or carrier aggregation, and information on performance requirements including at least one of a reception timing difference and a reception power difference that the received signal in the terminal device must satisfy for each of the plurality of CCs, so that the terminal device can receive signals of the plurality of CCs with a predetermined quality when MIMO with the number of layers indicated by the combination is used in each of the plurality of CCs; a determining means for determining a configuration of the number of MIMO layers to be used in the plurality of CCs based on the capability information; and a notifying means for notifying the terminal device of control information including the determined configuration. [Effects of the Invention]

[0008] According to the present invention, it is possible to perform communication using a plurality of component carriers in an appropriate configuration according to the processing capacity of the terminal device. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication system. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of a receiver of a terminal device. [Figure 3] FIG. 2 is a diagram illustrating an example of the configuration of a receiver of a terminal device. [Figure 4] FIG. 2 is a diagram illustrating an example of the configuration of a receiver of a terminal device. [Figure 5] 10A and 10B are diagrams illustrating an example of information notified from a terminal device to a base station device. [Figure 6] 10A and 10B are diagrams illustrating an example of information notified from a terminal device to a base station device. [Figure 7]FIG. 10 is a diagram illustrating an example of classification of types of terminal devices. [Figure 8] 10A and 10B are diagrams illustrating an example of information notified from a terminal device to a base station device. [Figure 9] 10A and 10B are diagrams illustrating an example of information notified from a terminal device to a base station device. [Figure 10] 10A and 10B are diagrams illustrating an example of information notified from a terminal device to a base station device. [Figure 11] FIG. 2 is a diagram illustrating an example of the hardware configuration of a terminal device and a base station device. [Figure 12] FIG. 2 is a diagram illustrating an example of a functional configuration of a terminal device. [Figure 13] FIG. 2 is a diagram illustrating an example of a functional configuration of a base station device. [Figure 14] FIG. 1 is a diagram illustrating an example of a flow of processing executed in a wireless communication system. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be arbitrarily combined. Furthermore, the same reference numerals are used for the same or similar components, and redundant explanations will be omitted.

[0011] FIG. 1 shows an example of the configuration of a wireless communication system according to the present embodiment. The wireless communication system conforms to the cellular communication standard of the Third Generation Partnership Project (3GPP (registered trademark)) and includes a base station device 101 and a terminal device 102. The cellular communication standard may be, for example, at least one of Long Term Evolution (LTE), New Radio (NR) for the fifth generation (5G), or a successor standard thereof. The terminal device 102 is configured to establish a connection with the base station device 101 and perform wireless communication. In the present embodiment, the terminal device 102 is configured to perform communication using multiple carriers by using dual connectivity (DC) or carrier aggregation (AC). For example, in FIG. 1, the terminal device 102 is configured to be able to communicate with the base station device 101 using a first carrier 111 and a second carrier 112. The first carrier 111 and the second carrier 112 are also referred to as component carriers (CC). Hereinafter, the first carrier 111 may be referred to as a first CC, and the second carrier 112 may be referred to as a second CC. Two or more CCs may be included in a common frequency band (any one of the 800 MHz band, the 2 GHz band, the 3.5 GHz band, etc.), or each CC may be included in a different frequency band. Furthermore, the terminal device 102 may be connected to one base station device 101, or may be connected to multiple base station devices 101. For example, the terminal device 102 may be connected to a first base station device that provides a communication service using the first CC, while also being connected to a second base station device that provides a communication service using the second CC.

[0012] To enhance communication in each of the multiple CCs, it is assumed that multi-input multi-output (MIMO) communication will be performed. In MIMO communication, communication is performed using multiple antennas provided in the base station device 101 and multiple antennas provided in the terminal device 102. In this embodiment, MIMO communication in which N antennas are used in the base station device 101 and M antennas are used in the terminal device 102 may be referred to as N×M MIMO. In this embodiment, as shown in FIG. 1 , one or more base station devices 101 communicate with the terminal device 102 using up to four antennas in the first CC and also communicate with the terminal device 102 using up to four antennas in the second CC. In this case, for example, if the terminal device 102 has eight antennas and corresponding communication processing circuits, it can perform 4×4 MIMO communication for each CC by using four antennas for communication in each CC. On the other hand, it is assumed that the terminal device 102 may be required to reduce the number of antennas and the circuit size, and therefore may not be able to have eight antennas and circuits. Furthermore, for example, when communication services using a first CC and a second CC are provided by separate base station devices, the received power difference and the received timing difference of signals transmitted through those CCs at the terminal device 102 may vary significantly. Furthermore, the allowable received power difference and the receive timing difference (which can sufficiently suppress the influence of interference between signals) may vary significantly depending on whether the terminal device 102 can process signals of multiple CCs using separate circuits. Therefore, if the base station device 101 does not have sufficient knowledge about the configuration of the terminal device 102, it may set a MIMO configuration that prevents the terminal device 102 from communicating with sufficient quality. Furthermore, if the base station device 101 does not have sufficient knowledge, it may unnecessarily suppress the use of MIMO communication, even if the terminal device 102 can tolerate a sufficiently large received power difference and receive timing difference, thereby reducing communication efficiency.

[0013] In this embodiment, in consideration of such circumstances, the terminal device 102 notifies the connected base station device 101 (network) of information on reception capabilities when MIMO communication is used in multiple CCs. Then, the base station device 101 controls the communication configuration based on that information. As a result, the base station device 101 can, for example, identify a configuration that allows the terminal device 102 to receive signals via multiple CCs and perform communication by specifying that configuration.

[0014] Here, several configuration examples of the receiver that the terminal device 102 may have will be described with reference to Figures 2 to 4. Note that Figures 2 to 4 show the configuration of the receiver of the terminal device 102 merely as an example, and a receiver having a configuration that is a modification of the configurations in Figures 2 to 4 may be used, or a receiver having a configuration that is completely different from the configurations in Figures 2 to 4 may be used.

[0015] 2 shows an example in which the terminal device 102 has eight independent receiving circuits. As shown in FIG. 2, one receiving circuit includes an antenna, a diplexer, a low-noise amplifier (LNA), an internal LNA (iLNA), a mixer, a filter, and an analog-to-digital converter (ADC). A signal received via the antenna passes through the diplexer to a signal of one frequency band, which is amplified by the LNA / iLNA, the mixer converts the signal frequency band to a baseband band, and the ADC digitizes the input analog signal and outputs it to a digital baseband circuit (not shown). In the example of FIG. 2, there are eight such receiving circuit systems, each configured to operate independently. When the terminal device 102 has such a configuration, each system can perform receiving processing by focusing only on the CC signal to be processed. Therefore, for example, by using up to four systems for the first CC and up to four systems for the second CC, sufficient reception performance can be obtained even if the difference in reception timing or reception power between the received signal in the first CC and the received signal in the second CC is relatively large.

[0016] FIG. 3 shows a configuration example in which an antenna, diplexer, and LNA are shared between two systems. In this example, for example, a combination of an iLNA, a mixer, a filter, and an ADC that handles signals from two CCs share one set of antenna, diplexer, and LNA. When such sharing is performed, it is expected that sufficient reception performance cannot be obtained unless the difference in reception timing and reception power between the received signals received in the two CCs is sufficiently small. Note that in the configuration of FIG. 3, for example, when 2×2 MIMO communication is performed in each of the two CCs, one set of iLNA, mixer, filter, and ADC that share one set of antenna, diplexer, and LNA does not need to be used. Therefore, in this case, sufficient reception performance can be obtained even if the difference in reception timing and reception power between the received signal in the first CC and the received signal in the second CC is relatively large. On the other hand, when 2×2 MIMO communication is performed in each of the two CCs, four receiving circuits can be used, each consisting of two sets of antennas, diplexers, and LNAs, and two sets of iLNAs, mixers, filters, and ADCs that share the same combination. In this case, it is possible to avoid using the remaining four receiving circuits, each consisting of two sets of antennas, diplexers, and LNAs, and two sets of iLNAs, mixers, filters, and ADCs that share the same combination. As a result, it is required that the differences in reception timing and reception power between the received signals in the first CC and the received signals in the second CC be relatively small, and by performing communication within this required range, power consumption in the terminal device 102 can be reduced.

[0017] Figure 4 shows a configuration intermediate between Figures 2 and 3, in which two sets of antennas, diplexers, and LNAs are shared by two systems, and two other sets of antennas, diplexers, and LNAs are used by only one system. When this configuration is used, there are only six combinations of iLNAs, mixers, filters, and ADCs, so 4x4 MIMO communication cannot be performed in each of the two CCs. In this case, 4x4 MIMO and 2x2 MIMO communication can be performed in the two CCs, respectively. Here, because two sets of antennas, diplexers, and LNAs are shared by two systems, it is expected that sufficient reception performance cannot be achieved unless the differences in reception timing and reception power between the received signals received by the two CCs are sufficiently small. On the other hand, when 2×2 MIMO communication is performed in each of the two CCs, one of the two sets of iLNAs, mixers, filters, and ADCs that share one set of antennas, diplexers, and LNAs does not need to be used. Therefore, in this case, sufficient reception performance can be obtained even if the difference in reception timing or reception power between the received signal in the first CC and the received signal in the second CC is relatively large. On the other hand, when 2×2 MIMO communication is performed in each of the two CCs, four receiving circuits can be used, consisting of two sets of antennas, diplexers, and LNAs and two sets of iLNAs, mixers, filters, and ADCs that share the same combination. In this case, the remaining two sets (the lower two systems) of receiving circuits consisting of antennas, diplexers, LNAs, iLNAs, mixers, filters, and ADCs can be omitted. As a result, it is required that the difference in reception timing and reception power between the received signal in the first CC and the received signal in the second CC be relatively small, and by carrying out communication within this required range, power consumption in the terminal device 102 can be reduced.

[0018] In the following, a receiving circuit in which an antenna, a diplexer, and an LNA are shared among multiple systems is referred to as a shared circuit. A receiving circuit in which an antenna, a diplexer, and an LNA are used in only one system is referred to as a separate circuit, since each system is separate. For example, the configuration of FIG. 2 is referred to as a separate circuit because, regardless of the type of communication performed between multiple CCs, the signal handled in each system is associated with only one CC. The configurations of FIGS. 3 and 4 are referred to as a shared circuit because, for example, when 4×4 MIMO communication is performed in at least one of two CCs, at least one combination of an antenna, a diplexer, and an LNA is shared among multiple systems. On the other hand, when 2×2 MIMO communication is performed in each of two CCs, the configurations of FIGS. 3 and 4 can be either a shared circuit or a separate circuit depending on the form of the circuit used.

[0019] For example, the terminal device 102 can notify the connected base station device 101 of information indicating whether communication using a separate circuit or a shared circuit is possible in communication of multiple CCs. For example, as shown in Figures 5(A) to 5(C), when either 4x4 MIMO or 2x2 MIMO is used in each of two CCs, the terminal device 102 can notify the base station device 101 of whether communication can be performed using the shared circuit or the separate circuit.

[0020] FIG. 5(A) shows an example of information that a terminal device 102 having the configuration of FIG. 2 notifies a base station device 101, for example. As shown in FIG. 5(A), when the terminal device 102 has the configuration of FIG. 2, it can perform both 4×4 MIMO and 2×2 MIMO communications using a separation circuit in each of the two CCs. On the other hand, when the terminal device 102 has the configuration of FIG. 2, it cannot perform communications using a shared circuit. FIG. 5(B) shows an example of information that a terminal device 102 having the configuration of FIG. 3 notifies a base station device 101, for example. As shown in FIG. 5(B), when the terminal device 102 has the configuration of FIG. 3, it can perform 4×4 MIMO communications in each of the two CCs, and can perform 4×4 MIMO communications in one CC while performing 2×2 MIMO communications in the other CC using a shared circuit, but cannot perform these communications using a separation circuit. Furthermore, when the terminal device 102 has the configuration of Fig. 3, when performing 2x2 MIMO communication in each of the two CCs, the communication can be performed using either a separation circuit or a shared circuit. Fig. 5(C) shows an example of information that the terminal device 102 having the configuration of Fig. 4 notifies the base station device 101. As shown in Fig. 5(C), when the terminal device 102 has the configuration of Fig. 4, it cannot perform 4x4 MIMO communication in each of the two CCs even if it uses a shared circuit. On the other hand, other cases are the same as in the case of the configuration of Fig. 3.

[0021] When the base station device 101 receives information such as those shown in FIGS. 5A to 5C from the terminal device 102, it can identify the configuration with which the terminal device 102 can perform communication. As an example, it is assumed that the base station device 101 receives information such as that shown in FIG. 5C from the terminal device 102. In this case, the base station device 101 may identify that 4×4 MIMO communication is not possible using both two CCs (the first CC and the second CC). Furthermore, the base station device 101 may identify that 4×4 MIMO communication is possible using one of the first CC and the second CC, and 2×2 MIMO communication is possible using the other, provided that a shared circuit is used in the terminal device 102. Furthermore, the base station device 101 may identify that 2×2 MIMO communication is possible using both the first CC and the second CC, regardless of whether a shared circuit or a separate circuit is used in the terminal device 102.

[0022] Here, for example, assume that one base station device 101 communicates with a terminal device 102. In this case, if signals are transmitted at the same timing using similar power in the first CC and the second CC, it is assumed that the difference in reception timing and reception power between the received signal in the first CC and the received signal in the second CC will be sufficiently small in the terminal device 102. That is, in this case, it is assumed that the terminal device 102 can receive the signals of the first CC and the second CC with sufficient quality even if it uses a shared circuit. Therefore, in this case, the base station device 101 assumes that the shared circuit can be applied to the terminal device 102, and can communicate with the terminal device 102 by selecting either a configuration in which only one of the first CC and the second CC uses 4×4 MIMO and the other uses 2×2 MIMO, or a configuration in which both the first CC and the second CC use 2×2 MIMO, which are communication possible using the shared circuit. In addition, when the base station device 101 decides to use a configuration using 2x2 MIMO for both the first CC and the second CC, it can further decide whether to have the terminal device 102 use a shared circuit or a separate circuit.

[0023] On the other hand, for example, if communication using the first CC and communication using the second CC are provided by separate base station devices 101, it is expected that the difference in reception timing and reception power between the received signal on the first CC and the received signal on the second CC will be large in the terminal device 102. In this case, if cooperative operation can be performed among the multiple base station devices 101 to sufficiently reduce the difference in reception timing and reception power, it is expected that the terminal device 102 will be able to perform communication with sufficiently high quality even if it uses a shared circuit. On the other hand, if such cooperative operation cannot be performed among the multiple base station devices 101, communication quality may be degraded if the terminal device 102 uses a shared circuit. For this reason, the base station device 101 (e.g., a master base station) providing communication using one of the CCs may decide to have the terminal device 102 use a separate circuit, and may decide to use a configuration using 2×2 MIMO for both the first CC and the second CC, for example.

[0024] In this way, the terminal device 102 can notify the base station device 101 of information indicating whether a separation circuit or a shared circuit can be used when performing MIMO communication using multiple CCs. This allows the base station device 101 to determine the number of MIMO layers (4×4, 2×2, etc.) to be used in each of multiple CCs, taking into account the configuration of the receiver of the terminal device 102. Note that while the above example describes the case where two CCs are used, three or more CCs may be considered. For example, as shown in FIGS. 6(A) to 6(C), when either 4×4 MIMO or 2×2 MIMO is used in each of three CCs, the terminal device 102 can notify the base station device 101 of whether communication can be performed using a shared circuit or a separation circuit. Note that, in one example, FIG. 6(A) corresponds to the configuration of FIG. 2, FIG. 6(B) corresponds to the configuration of FIG. 3, and FIG. 6(C) corresponds to the configuration of FIG. 4. When three CCs are used, the configurations in FIGS. 2 to 4 only allow for signal processing of up to eight systems. Therefore, configurations in which the total number of streams exceeds eight, such as a configuration in which 4×4 MIMO is used in two or more of the three CCs, are not shown. Naturally, the terminal device 102 can have a receiving circuit capable of processing more than eight streams. Depending on the configuration, information regarding whether 4×4 MIMO can be used for each of the three or more CCs may be notified to the base station device 101. While FIGS. 5(A) to 5(C) and 6(A) to 6(C) only show the number of MIMO layers for each CC and whether communication is possible with that number of layers, this is not limiting. For example, the terminal device 102 may notify the base station device 101 of information such as the fact that a specific combination of CCs can be processed using a shared circuit, but other combinations cannot be processed even using a shared circuit. For example, at least one of information indicating a combination of CCs that can be processed using a shared circuit and information indicating a combination of CCs that cannot be processed using a shared circuit may be notified from the terminal device 102 to the base station device 101.

[0025] 2 to 4, the type of the terminal device 102 may be defined in advance, and the terminal device 102 may notify the base station device 101 of the type of receiver configuration of the terminal device 102. FIG. 7 shows an example of information indicating the receiver type of the terminal device 102. In FIG. 7, UE Type=1 corresponds to a configuration in which four receiver circuits are available for each of two CCs (eight in total), and the receiver circuits share not only the antenna and LNA but also the mixer. UE Type=2 corresponds to a configuration in which two receiver circuits are provided for each CC (four in total), each with a separate antenna. In other words, UE Type=2 corresponds to a configuration in which the number of circuits is four in the configuration in FIG. 2. Similarly, UE Type=3a corresponds to the configuration in FIG. 4, UE Type=3b corresponds to the configuration in FIG. 3, UE Type=4a corresponds to a configuration in which the number of circuits is four in the configuration in FIG. 2, and UE Type=4b corresponds to the configuration in FIG. 2. The terminal device 102 can notify the base station device 101 of the UE Type 1 to 4b of the configuration of its receiver. The configurations and UE Types shown in FIGS. 2 to 4 are merely examples. For example, in the above example, one diplexer and one LNA are associated with one antenna, but this configuration is not limiting. For example, two or more diplexers or LNAs and their subsequent circuits may be associated with one antenna, or one diplexer or LNA and their subsequent circuits may be associated with two antennas. Furthermore, for example, multiple digital baseband processing circuits may be provided downstream of the configurations shown in FIGS. 2 to 4. Here, one digital baseband processing circuit may process only one CC, or may process multiple CCs. Furthermore, multiple digital baseband processing circuits may be configured to process one CC. In this case, determining whether the shared circuit described above can be used may take into account whether the digital baseband processing circuit can be shared for communication processing of multiple CCs.

[0026] Note that even when using a shared circuit, for example, the terminal device 102 may be able to perform reception processing with sufficiently high quality even when there is a relatively large difference in reception timing or reception power between received signals from multiple CCs, due to, for example, its signal processing capabilities. In this case, if the above-described UE Type information is simply notified to the base station device 101, the base station device 101 may select a configuration that is conservative compared to the actual capabilities of the terminal device 102 (i.e., relatively inefficient compared to the capabilities of the terminal device 102). For this reason, the terminal device 102 may notify the base station device 101 of information on performance requirements, which indicate what requirements must be met in each CC to enable signals to be received with sufficient quality, regardless of the receiver configuration.

[0027] For example, the performance requirements may be specified by the Maximum Receive Timing Difference (MRTD), which indicates the maximum value of the receive timing difference between CCs, or the maximum value of the receive power difference (power imbalance) between CCs. As an example, a performance requirement where the allowable MRTD is 33 microseconds (μs) and the allowable receive power difference is 25 dB is referred to as performance requirement A. Also, a performance requirement where the allowable MRTD is 3 μs and the allowable receive power difference is 6 dB is referred to as performance requirement B. Performance requirement B is a performance requirement that is expected to be achieved, for example, when the same base station device provides communications using multiple CCs, or when multiple base station devices located in the same location provide communications using different CCs. Performance requirement A is a performance requirement that is expected to be achieved even when multiple base station devices located in different locations provide communications using different CCs. In addition to performance requirements A and B, another requirement may be provided, for example, where the MRTD is greater than 3 μs and less than 33 μs, or the maximum receive power difference is greater than 6 dB and less than 25 dB. Alternatively, another requirement may be provided, such as MRTD being less than 3 μs or greater than 33 μs, or the maximum received power difference being less than 6 dB or greater than 25 dB. Values ​​such as 3 μs, 33 μs, 6 dB, and 25 dB are merely examples, and values ​​other than these may be used to define the performance requirements. While MRTD may be used as a performance requirement for downlink dual connectivity or carrier aggregation, maximum uplink transmission timing difference (MTTD) may be used as a performance requirement for uplink dual connectivity or carrier aggregation instead of MRTD.

[0028] The terminal device 102 can notify the base station device 101 of information indicating which performance requirement needs to be satisfied to enable communications with sufficient quality for a combination of the number of MIMO layers in each CC. FIGS. 8(A) to 8(C) show examples of the performance requirement information notified in this case. Note that FIG. 8(A) corresponds to the configuration in FIG. 2, FIG. 8(B) corresponds to the configuration in FIG. 3, and FIG. 8(C) corresponds to the configuration in FIG. 4, respectively. Note that in the examples of FIGS. 8(A) to 8(C), performance requirement A is satisfied when communications can be performed using a demultiplexing circuit, and performance requirement B is satisfied when communications cannot be performed using a demultiplexing circuit but can be performed using a shared circuit. The terminal device 102 having the configuration in FIG. 2 can perform communications using a demultiplexing circuit for each combination of the number of MIMO layers in the CC, and can perform communications with sufficient quality if "performance requirement A" is satisfied for each configuration. For this reason, such a terminal device 102 notifies the base station device 101 of information indicating "performance requirement A" as information on the performance requirement corresponding to each combination, as shown in FIG. 8(A). Furthermore, the terminal device 102 having the configuration of FIG. 3 can perform communication using a shared circuit for each combination of the number of MIMO layers in the CC, and can also perform communication using a separate circuit when 2×2 MIMO communication is performed in both the first CC and the second CC. That is, if "performance requirement A" is satisfied for a combination in which both the first CC and the second CC use 2×2 MIMO, communication can be performed with sufficient quality, and if "performance requirement B" is satisfied for other combinations, communication can be performed with sufficient quality. For this reason, such a terminal device 102 notifies the base station device 101 of information on the performance requirement corresponding to each combination, as shown in FIG. 8(B). Furthermore, the terminal device 102 having the configuration of FIG. 4 cannot perform communication when 4×4 MIMO is used in two CCs, but can perform the same processing as the terminal device 102 having the configuration of FIG. 3 in other configurations. For this reason, such a terminal device 102 notifies the base station device 101 of information on performance requirements corresponding to each combination, as shown in FIG. 8(C).

[0029] Note that the relationship between the configuration of the terminal device 102 and the performance requirements that enable communication with sufficient quality in the above description is merely an example. That is, even if the terminal device 102 has a configuration such as that shown in FIG. 2, it can be configured to enable communication using a shared circuit by using a common digital baseband processing circuit for received signals of multiple CCs. Even if a shared circuit is used, a terminal device 102 that enables communication with sufficient quality under requirements (e.g., performance requirement A) that are more relaxed than performance requirement B due to the sophistication of the circuit may be used. Regardless of the configurations such as those shown in FIGS. 2 to 4, the terminal device 102 can notify the base station device 101 of information on performance requirements (e.g., at least one of a reception timing difference and a reception power difference) that must be satisfied for communication using each combination of the number of MIMO layers in each of multiple CCs to be able to perform the communication using that combination at a predetermined communication quality.

[0030] 8(A) to 8(C) show performance requirements that must be satisfied when the terminal device 102 performs communication, and when the performance requirements are satisfied or when stricter requirements are satisfied, the terminal device 102 can perform communication with a predetermined quality. That is, the terminal device 102 can perform communication with a predetermined quality when performance requirement A is satisfied for a combination of a predetermined number of MIMO layers in each of a plurality of CCs, and can also perform communication with a predetermined quality when performance requirement B is satisfied. Therefore, when the base station device 101 receives information such as that shown in FIG. 8(A), for example, the base station device 101 does not recognize whether a separate circuit or a shared circuit is used in the terminal device 102, but can recognize that the terminal device 102 can receive a signal with a predetermined quality if performance requirement A or a stricter requirement is satisfied.

[0031] For example, instead of the information as shown in Figures 8(A) to 8(C), information on performance requirements to enable signals to be received with a predetermined quality in communications using a separated circuit and a shared circuit, as shown in Figures 9(A) to 9(C), may be notified from the terminal device 102 to the base station device 101.

[0032] 8(A) to 8(C) and 9(A) to 9(C) show examples in which information about two CCs is notified, but similar information can also be notified when three or more CCs are available. For example, as shown in FIGS. 6(A) to 6(C), combinations of the number of MIMO layers for three CCs are defined, and performance requirements that enable communication with a predetermined quality when the combinations are used can be notified. For example, in the information corresponding to FIG. 6(B), if 4×4 MIMO is used in one of the first to third CCs and 2×2 MIMO is used in the other CCs, a shared circuit will be used, and performance requirement B will be notified for these combinations. On the other hand, if 2×2 MIMO is used in each of the first to third CCs, it is assumed that a shared circuit will be used for two of these three CCs and a separate circuit will be used for the remaining CC. For this reason, for example, information such as performance requirement B for the first CC and second CC and performance requirement A for the third CC may be notified from the terminal device 102 to the base station device 101. Note that different information may be notified depending on which of the first to third CCs a demultiplexing circuit is used for. For example, FeatureSetsPerBands (described later) may be notified for three patterns: when a demultiplexing circuit is used for the first CC, when a demultiplexing circuit is used for the second CC, and when a demultiplexing circuit is used for the third CC. Furthermore, for example, when three CCs are used, five patterns can be considered: a pattern in which the received signals of the three CCs are all processed by a common shared circuit (pattern 1); a pattern in which the first and second CCs are processed by a shared circuit and the third CC is processed by a separation circuit (pattern 2); a pattern in which the first and third CCs are processed by a shared circuit and the second CC is processed by a separation circuit (pattern 3); a pattern in which the second and third CCs are processed by a shared circuit and the first CC is processed by a separation circuit (pattern 4); and a pattern in which the first to third CCs are each processed by a separation circuit (pattern 5).Here, for each combination of the number of MIMO layers used in multiple CCs, information on performance requirements for each of these five patterns may be notified from the terminal device 102 to the base station device 101. Note that, for each pattern, information on performance requirements between two of the three CCs may be notified. That is, three performance requirements may be notified for each pattern: the performance requirement between the first CC and the second CC, the performance requirement between the first CC and the third CC, and the performance requirement between the second CC and the third CC. Also, for each combination of the number of MIMO layers used in multiple CCs, a bitmap indicating whether each of these five patterns is usable may be notified. That is, whether communication is possible using patterns 1 to 5 may be indicated by five-bit information. In one example, a bitmap "11110" may indicate that communication is possible using patterns 1 to 4, but that communication is not possible using pattern 5. Such a bitmap may be notified for each combination of the number of MIMO layers used in multiple CCs. A first bitmap indicating a pattern in which communication is possible when performance requirement A is satisfied, and a second bitmap indicating a pattern in which communication is possible when performance requirement B is satisfied may be notified to the base station device 101. When three or more CCs are used, the terminal device 102 may notify the base station device 101 of only a combination of CCs that can satisfy performance requirement A. When, for example, one system such as an antenna / diplexer / LNA is branched into three or more systems and three or more CCs included in a signal received from one antenna are configured to be processed, information on requirements that allow signals of these three or more CCs to be processed collectively may be notified from the terminal device 102 to the base station device 101.

[0033] The above information may be notified from the terminal device 102 to the base station device 101 using, for example, UE Capability (capability information) defined in a cellular communication standard. In one example, the above information may be notified using FeatureSetsPerBands, which is an element of information on Band Combination included in the UE Capability. For example, when information such as those shown in FIGS. 5(A) to 5(C) or 6(A) to 6(C) is notified, FeatureSetsPerBands may be configured to include, for each combination of CCs used in dual connectivity or carrier aggregation, information on the number of layers of each CC and information indicating whether a separate circuit and a shared circuit can be used. FIG. 10(A) shows an example of information included in FeatureSetsPerBands when, for example, information such as that shown in FIG. 5(B) is notified. Furthermore, when information such as those shown in Figures 8(A) to 8(C) or 9(A) to 9(C) is notified, FeatureSetsPerBands can be configured to include, for example, for each combination of CCs, information on the number of layers of each CC and the performance requirement (P / R) required when performing communication using that combination of layer numbers (for each separate circuit / shared circuit in the case of Figures 9(A) to 9(C)). Figure 10(B) shows an example of information that can be included in FeatureSetsPerBands when information such as that shown in Figure 8(B) is notified. Note that, for a combination of the number of MIMO layers for which communication is not possible, information indicating that communication is not possible may be notified, or notification of information regarding that combination may be omitted.

[0034] The predetermined quality that should be obtained when the performance requirement is satisfied can be defined, for example, by a throughput value. For example, the performance requirement may be defined by a throughput value (e.g., 80% of the theoretical value) that should be satisfied when the reception power difference is a predetermined value (e.g., 6 dB or 25 dB). Also, the performance requirement may be defined by a throughput value (e.g., 80% of the theoretical value) that should be satisfied when the reception timing difference is a predetermined value (e.g., 3 μs or 33 μs).

[0035] Upon receiving the above-described information, the base station device 101 may determine, based on the information, a MIMO configuration to be used for each CC in communication with the terminal device 102. In one example, the base station device 101 receives from the terminal device 102 information on the received power and reception timing at the terminal device 102 for signals (e.g., reference signals such as synchronization signals and channel state information-reference signals) transmitted from each CC to be used in communication with the terminal device 102. This allows the base station device 101 to identify the received power difference and reception timing difference at the terminal device 102 for signals transmitted using each CC. The base station device 101 may then determine a MIMO configuration to be used in communication with the terminal device 102 according to the received power difference and reception timing difference. For example, if the received power difference or reception timing difference exceeds a predetermined value (e.g., 6 dB or 3 μs), the base station device 101 may determine to use a MIMO configuration that enables communication using a demultiplexing circuit. Furthermore, if the difference in received power or received timing does not exceed a predetermined value, it may be determined to use either a separate circuit or a shared circuit. Note that, if the difference in received power or received timing for a specific CC combination exceeds a second predetermined value (e.g., 25 dB or 33 μs), the base station device 101 may determine not to use that CC combination. Note that, if three or more CCs are used, the above-mentioned determination may be made based on the maximum value of the difference in received power or received timing.

[0036] The base station device 101 may, for example, measure signals transmitted from the terminal device 102 on each CC to estimate the received power difference or the received timing difference between CCs at the terminal device 102, or may determine the received timing difference between CCs at the terminal device 102 based on, for example, timing advance values ​​for each CC set for the terminal device 102. Furthermore, when multiple CCs are provided by a single base station device 101 or by multiple base station devices 101 located at the same location (or within a predetermined distance range where they can be treated as being at the same location), the base station device 101 may estimate that the received power difference or the received timing difference will be equal to or less than a predetermined value, regardless of the actual measured values ​​of signals at the terminal device 102, etc. On the other hand, when multiple CCs are provided by multiple base station devices 101 located at different locations (outside a predetermined distance range where they cannot be treated as being at the same location), the base station device 101 may estimate that the received power difference or the received timing difference will be equal to or greater than a predetermined value, regardless of the actual measured values ​​of signals at the terminal device 102, etc.

[0037] In addition to the MIMO configuration for each CC, the base station device 101 may determine whether the terminal device 102 should use a demultiplexing circuit or a shared circuit. For example, if only one of the demultiplexing circuit and the shared circuit can be used for communication in the determined MIMO configuration, which of these circuits should be used is uniquely determined. On the other hand, if both the demultiplexing circuit and the shared circuit can be used for communication in the determined MIMO configuration, the base station device 101 may determine which of them to use. For example, when a demultiplexing circuit is used, more circuit parts must be operated in the terminal device 102 than when a shared circuit is used, resulting in higher power consumption. For this reason, the base station device 101 may determine to have the terminal device 102 use the shared circuit when the terminal device 102 should operate in a more power-saving state. On the other hand, when a demultiplexing circuit is used, communication reliability can be improved, for example, by maintaining communication even when the reception timing difference or the reception power difference becomes large due to a change in the situation. For this reason, the base station device 101 may determine to have the terminal device 102 use the demultiplexing circuit when communication reliability should be improved. The base station device 101 may then notify the terminal device 102 of information indicating whether to use a separate circuit or a shared circuit.

[0038] 10A from the terminal device 102, the base station device 101 may notify the terminal device 102 of information specifying the number of MIMO layers (maxMIMO-Layers) of the first CC=4, the number of MIMO layers of the second CC=4, and the reception method=shared circuit. In this case, the base station device 101 may notify the terminal device 102 of information specifying the number of MIMO layers of the first CC=4, the number of MIMO layers of the second CC=4, and the reception method=shared circuit. In this case, the information specifying the reception method=shared circuit may be uniquely determined by the number of MIMO layers, and therefore the information does not need to be notified to the terminal device 102. Furthermore, when the base station device 101 determines to use 2×2 MIMO for both the first CC and the second CC and determines that a demultiplexing circuit should be used, the base station device 101 may notify the terminal device 102 of information specifying the number of MIMO layers of the first CC=2, the number of MIMO layers of the second CC=2, and the reception method=demultiplexing circuit. In addition, if the base station device 101 determines that a shared circuit should be used, it can notify the terminal device 102 of information specifying the number of MIMO layers for the first CC = 2, the number of MIMO layers for the second CC = 2, and the receiving method = shared circuit.

[0039] The base station device 101 may not determine or notify whether the separate circuit or the shared circuit should be used, and the terminal device 102 may instead determine whether the separate circuit or the shared circuit should be used. For example, as described above, the terminal device 102 may determine whether to use the separate circuit or the shared circuit based on criteria such as power consumption and communication reliability requirements, without relying on instructions from the base station device 101. Furthermore, if the terminal device 102 does not receive information specifying whether to use the separate circuit or the shared circuit, it may determine which circuit to use based on a pre-setting.

[0040] The terminal device 102 may notify the base station device 101, as capability information, whether it has the capability to accept designation of whether a separate circuit or a shared circuit should be used. If the terminal device 102 has that capability, the base station device 101 may notify the terminal device 102 of information designating which circuit should be used. In another example, the terminal device 102 may notify the base station device 101, as capability information, whether it has the capability to determine whether a separate circuit or a shared circuit should be used. If the terminal device 102 does not have that capability, the base station device 101 may notify the terminal device 102 of information designating which circuit should be used.

[0041] Furthermore, in the above example, an example in which two CCs are used has been described. However, when three or more CCs are used, information on the number of MIMO layers for each CC and information indicating the reception method can be similarly notified from the base station device 101 to the terminal device 102. In this case, too, if the reception method of the terminal device 102 is uniquely determined by the combination of the number of MIMO layers, information on the reception method does not need to be notified. Note that the base station device 101 may use information of the above patterns as information indicating the reception method. That is, for example, when pattern 1 is specified, it indicates that the received signals of all three CCs should be processed by a common shared circuit. Furthermore, when pattern 5 is specified, it indicates that the first to third CCs should each be processed by a separate circuit.

[0042] Furthermore, the base station device 101 may specify information indicating performance requirements that are expected to be satisfied in each CC and notify the terminal device 102. For example, when the base station device 101 communicates with the terminal device 102 using multiple CCs, the base station device 101 may notify the terminal device 102 of information indicating that signals are transmitted so that the above-mentioned performance requirement B is satisfied. Furthermore, when another base station device that is located at a different location from the base station device 101 (at least located outside a predetermined distance range from the base station device 101) communicates with the terminal device 102 using separate CCs, the base station device 101 may notify the terminal device 102 of information indicating that signals are transmitted so that the above-mentioned performance requirement A is satisfied. Furthermore, in one example, when the base station device 101 provides a communication service using a first CC through a first Transmission and Reception Point (TRP) and provides a communication service using a second CC through a second TRP, the base station device 101 may notify the terminal device 102 of information indicating that signals are transmitted so that the above-mentioned performance requirement A is satisfied. That is, when the distance between the antennas of the signal transmitters in each CC is greater than a predetermined distance, the base station device 101 can notify the terminal device 102 of information indicating that the signal will be transmitted so as to satisfy performance requirement A, and when the distance is less than the predetermined distance, the base station device 101 can notify the terminal device 102 of information indicating that the signal will be transmitted so as to satisfy performance requirement B.

[0043] When the terminal device 102 is notified of such performance requirement information, it selectively uses either a demultiplexing circuit or a shared circuit so that communication can be performed with sufficient quality when the communication is performed under the performance requirement. For example, when the terminal device 102 receives notification that signals are transmitted so as to satisfy the above-mentioned performance requirement A, it receives signals using a configuration that can tolerate the magnitude of the reception timing difference, reception power difference, etc. between CCs defined as the performance requirement. For example, the terminal device 102 receives signals transmitted on each CC under performance requirement A by using a demultiplexing circuit or a signal processing circuit that makes communication under the performance requirement acceptable. Also, when the terminal device 102 receives notification that signals are transmitted so as to satisfy the above-mentioned performance requirement B, it can determine that the differences in the reception timing difference, reception power difference, etc. between signals transmitted from each of the multiple CCs are small. Therefore, the terminal device 102 can perform communication using, for example, a shared circuit. Note that, when a demultiplexing circuit is available, the terminal device 102 may decide to use the shared circuit in important cases where reducing power consumption is a priority, and to use the demultiplexing circuit in cases where executing communication on each CC with higher accuracy is a priority.

[0044] Assume that the base station device 101 provides communication services using both the first CC and the second CC and receives information such as that shown in FIG. 10B from the terminal device 102. In this case, the base station device 101 can assume that the reception timing difference and reception power difference between the signals of the two CCs at the terminal device 102 are sufficiently small, and therefore can assume that performance requirement B is met. Therefore, the base station device 101 can determine, for example, to use 4×4 MIMO for both the first CC and the second CC. In this case, the base station device 101 can notify the terminal device 102 of information specifying the number of MIMO layers of the first CC (maxMIMO-Layers)=4, the number of MIMO layers of the second CC=4, and performance requirement B (performance requirement B). Furthermore, when the base station device 101 determines to use 2×2 MIMO for both the first CC and the second CC under the same conditions, it may notify the terminal device 102 of information specifying that the number of MIMO layers for the first CC is 2, the number of MIMO layers for the second CC is 2, and performance requirement B. In other words, since performance requirement B is met regardless of the number of MIMO layers, this information may be notified to the terminal device 102. In this case, the terminal device 102 can independently determine whether to use a separation circuit capable of receiving processing even under performance requirement A, or a shared circuit capable of receiving processing under performance requirement B. Note that the base station device 101 may not notify information about the performance requirement when allowing the terminal device 102 to independently determine whether to use a separation circuit or a shared circuit.

[0045] 9(A) to 9(C) from the terminal device 102, the base station device 101 may use information on performance requirements for specifying whether the terminal device 102 should use a demultiplexing circuit or a shared circuit. For example, when the base station device 101 receives information such as that shown in FIG. 9(B) from the terminal device 102, the base station device 101 may notify the terminal device 102 that a demultiplexing circuit should be used by transmitting to the terminal device 102 information specifying that the number of MIMO layers of the first CC is 2, the number of MIMO layers of the second CC is 2, and performance requirement is A. When the base station device 101 receives information such as that shown in FIG. 9(B) from the terminal device 102, the base station device 101 may notify the terminal device 102 that a shared circuit should be used by transmitting to the terminal device 102 information specifying that the number of MIMO layers of the first CC is 2, the number of MIMO layers of the second CC is 2, and performance requirement is B.

[0046] On the other hand, if the base station device 101 provides a communication service using a first CC and another base station device provides a communication service using a second CC, it can be assumed that the difference in reception timing or reception power between the signals of the two CCs will be large at the terminal device 102. For this reason, it can be assumed that the base station device 101 will be able to communicate within the range of performance requirement A, without satisfying performance requirement B. In this case, the base station device 101 may determine, for example, to use 2×2 MIMO for both the first CC and the second CC. Then, the base station device 101 may notify the terminal device 102 of information specifying that the number of MIMO layers for the first CC is 2, the number of MIMO layers for the second CC is 2, and performance requirement A is A. In these cases, if the reception configuration of the terminal device 102 is uniquely determined only by the number of MIMO layers for each CC, information on the performance requirements does not need to be notified to the terminal device 102. For example, when 4x4 MIMO is used in both the first CC and the second CC, the base station device 101 recognizes that performance requirement B must be met, and by specifying such a MIMO configuration, it is assumed that performance requirement B is met.

[0047] Note that, although the above example has been described with reference to an example in which two CCs are used, when three or more CCs (carriers) are used, information on the number of MIMO layers for each CC and information indicating the performance requirements can be similarly notified from the base station device 101 to the terminal device 102. For example, when all three CCs are provided from the same base station device, it is expected that the reception timing differences and reception power differences between the signals of the three CCs will be sufficiently small. For this reason, the base station device 101 can instruct the terminal device 102 to process all signals received from the three CCs using a common shared circuit. In this case, the base station device 101 may notify the terminal device of information indicating that signals will be transmitted so that all signals of the three CCs satisfy performance requirement B. Furthermore, when the first CC and the second CC are provided by the same base station device and the third CC is provided by another base station device located at a different location, it is assumed that the difference in reception timing and reception power between the first CC and the second CC signals will be sufficiently small, and that the difference in reception timing and reception power between the third CC and the first CC and between the third CC and the second CC signals will be large. Therefore, the base station device 101 may instruct the terminal device 102 to process the first CC and the second CC using a shared circuit and process the third CC using a separate circuit. In this case, the base station device 101 may notify the terminal device 102 of information indicating that the signals from the first CC and the second CC are transmitted so that performance requirement B is satisfied, and the signals from the third CC are transmitted so that performance requirement A is satisfied. Furthermore, if the first CC and the third CC are provided by the same base station device and the second CC is provided by another base station device located in a different location, it is expected that the difference in reception timing and reception power between the first CC and the third CC signals will be sufficiently small, while the difference in reception timing and reception power between the second CC and the first CC, and between the second CC and the third CC signals will be large. Therefore, the base station device 101 can instruct the terminal device 102 to process the first CC and the third CC using a shared circuit and to process the second CC using a separate circuit.In this case, the base station device 101 may notify the terminal device 102 of information indicating that signals from the first CC and the third CC are transmitted so as to satisfy performance requirement B, and that signals from the second CC are transmitted so as to satisfy performance requirement A. Furthermore, when the second CC and the third CC are provided from the same base station device and the first CC is provided from another base station device located in a different location, it is assumed that the difference in reception timing and reception power between the signals from the second CC and the third CC will be sufficiently small, and that the difference in reception timing and reception power between the signals from the first CC and the second CC, and between the signals from the first CC and the third CC, will be large. For this reason, the base station device 101 may instruct the terminal device 102 to process the second CC and the third CC using a shared circuit and to process the first CC using a separate circuit. In this case, the base station device 101 may notify the terminal device 102 of information indicating that signals from the second CC and the third CC are transmitted so as to satisfy performance requirement B, and that signals from the first CC are transmitted so as to satisfy performance requirement A. Furthermore, if the first to third CCs are all provided from different base station devices located in different locations, it is expected that there will be large differences in the reception timing and reception power of all the signals. For this reason, the base station device 101 may instruct the terminal device 102 to process the first to third CCs using respective separation circuits. In this case, the base station device 101 may notify the terminal device 102 of information indicating that the signals from the first to third CCs are transmitted so as to satisfy the performance requirement A.

[0048] Furthermore, information on the performance requirements satisfied by the first to third CCs may be defined as patterns, and information on which pattern should be used may be notified from the base station device 101 to the terminal device 102. In the above example, the following patterns may be defined: a pattern (pattern 1) in which all three CC signals are transmitted so as to satisfy performance requirement B; a pattern (pattern 2) in which the third CC signal is transmitted so as to satisfy performance requirement A so that the first and second CC signals satisfy performance requirement B; a pattern (pattern 3) in which the second CC signal is transmitted so as to satisfy performance requirement A so that the first and third CC signals satisfy performance requirement B; a pattern (pattern 4) in which the first CC signal is transmitted so as to satisfy performance requirement A so that the second and third CC signals satisfy performance requirement B; and a pattern (pattern 5) in which all combinations of the first to third CC signals are transmitted so as to satisfy performance requirement A. Then, the base station device 101 can notify the terminal device 102 of information on the pattern in which the signal is transmitted (how the terminal device 102 should perform reception processing).

[0049] In this case, too, when the reception configuration of the terminal device 102 is uniquely determined by the combination of the number of MIMO layers, information regarding the performance requirement does not need to be notified. Furthermore, although an example in which three CCs are used and each CC is treated equally has been described here, some combinations of CCs may be treated differently from other CCs. For example, different treatment may be performed depending on the Radio Access Technology (RAT) used for each CC. For example, when three frequency band CCs, B42 (LTE: 3.5 GHz band), n77L (NR: 3.8 GHz-4.1 GHz), and n77H (NR: 3.9 GHz-4.2 GHz), are used, it is assumed that signals for n77L and n77H are transmitted from a single NR base station device (at the same location) due to NR carrier aggregation. Therefore, communication between these may be treated as always satisfying performance requirement B. On the other hand, because B42 is a carrier wave used by LTE base station devices, signals transmitted by that carrier wave may be transmitted from a different location than that of an NR base station device, and it may not be appropriate to treat it as always satisfying performance requirement B. For this reason, the base station device 101 may not transmit any special instructions for n77L and n77H, but may transmit information to the terminal device 102 that can specify whether a shared circuit or a separate circuit should be used for B42. The terminal device 102 may always perform reception processing of CC signals for n77L and n77H using the shared circuit, and may selectively use either the shared circuit or the separate circuit for reception processing of CC signals for B42 in accordance with instructions from the base station device 101.

[0050] For example, when starting dual connectivity or carrier aggregation, the base station device 101 transmits an RRC Reconfiguration message to the terminal device 102. RRC is an abbreviation for Radio Resource Control. The base station device 101 receives the above-mentioned UE Capability information and, based on that information, can notify the terminal device 102 of the configuration of CCs to be used by the terminal device 102 (information such as the number of MIMO layers) by using this RRC Reconfiguration message. The terminal device 102 receives SpCellConfig and SCellConfig, which include information on CCs to be used for dual connectivity or carrier aggregation, from the base station device 101. That is, SpCellConfig is received for CCs for which uplink signals are transmitted, and SCellConfig is received for CCs for which uplink signals are not transmitted. SpCellConfig and SCellConfig each include information on the maximum number of MIMO layers (maxMIMO-Layers) and the carrier frequency of the CC (frequencyInfoDL). In this embodiment, in addition to these two pieces of information, information on performance requirements related to received signals in the terminal device 102 between CCs used in dual connectivity or carrier aggregation, information on the circuit configuration to be used, and the like can be specified. For example, if the base station device 101 determines that two CCs should be processed by a shared circuit, SpCellConfig and SCellConfig including frequencyInfoDL specifying the frequencies of each of these two CCs, maxMIMO-Layers specifying the maximum number of MIMO layers for each CC, and information specifying whether a shared circuit or a separate circuit should be used when these CCs are used can be notified from the base station device 101 to the terminal device 102. Note that the information specifying whether a shared circuit or a separate circuit should be used when multiple CCs are used may be specified by an information element separate from SpCellConfig and SCellConfig.Also, as described above, instead of information specifying whether a shared circuit or a separate circuit should be used when multiple CCs are used, information on performance requirements may be included in the RRC Reconfiguration message and transmitted.

[0051] FIG. 11 shows an example of the hardware configuration of the base station device 101 and the terminal device 102 according to this embodiment. In one example, the base station device 101 and the terminal device 102 are configured to include a processor 1101, a ROM 1102, a RAM 1103, a storage device 1104, and a communication circuit 1105. The processor 1101 is a computer configured to include one or more processing circuits, such as a general-purpose CPU (Central Processing Unit) or an ASIC (Application Specific Integrated Circuit), and executes overall control processing of the device and each of the above-mentioned processes by reading and executing programs stored in the ROM 1102 or the storage device 1104. The ROM 1102 is a read-only memory that stores information such as programs and various parameters related to processes executed by the base station device 101 and the terminal device 102. The RAM 1103 functions as a workspace when the processor 1101 executes a program, and is also a random access memory that stores temporary information. The storage device 1104 is configured, for example, by a removable external storage device. The communication circuit 1105 is configured by, for example, circuits for wireless communication of LTE, 5G, or successor standards. Although one communication circuit 1105 is illustrated in FIG. 11 , the base station device 101 and the terminal device 102 may have multiple communication circuits. For example, the base station device 101 and the terminal device 102 may have wireless communication circuits for LTE, 5G, and successor standards, respectively, and a common antenna for these circuits. The base station device 101 and the terminal device 102 may also have separate antennas suitable for each standard. The base station device 101 may also have a wired communication circuit used when communicating with other base station devices or nodes in the core network. The terminal device 102 may also have a communication circuit compliant with a wireless communication standard other than a cellular communication standard, such as a wireless local area network (LAN) or Bluetooth (registered trademark). The base station device 101 and the terminal device 102 may have separate communication circuits 1105 for each of a plurality of usable frequency bands, or may have a common communication circuit 1105 for at least some of these frequency bands. The communication circuit 1105 of the terminal device 102 includes the configurations shown in FIGS. 2 to 4.

[0052] FIG. 12 shows an example of the functional configuration of the terminal device 102. The terminal device 102 includes, for example, a capability information notification unit 1201 and a communication control unit 1202. Note that FIG. 12 only shows functions particularly related to the present embodiment, and various other functions that the terminal device 102 may have are omitted from the illustration. For example, the terminal device 102 naturally has other functions that terminal devices 102 compliant with LTE, 5G, and subsequent standards generally have. The functional blocks in FIG. 12 are shown schematically, and the respective functional blocks may be integrated or further subdivided. Each function in FIG. 12 may be realized, for example, by the processor 1101 executing a program stored in the ROM 1102 or the storage device 1104, or may be realized, for example, by a processor within the communication circuit 1105 executing predetermined software. Since the details of the processing performed by each functional unit are as described above, only the general functions of the terminal device 102 will be outlined here.

[0053] The capability information notifying unit 1201 notifies the base station device 101 of information on combinations of the number of MIMO layers for multiple CCs usable by the terminal device 102, as described above, and information indicating the configuration to be used in the terminal device 102 or the performance requirements that processable signals should satisfy when the number of MIMO layers indicated by the combination is used in each of the multiple CCs. The capability information notifying unit 1201 notifies the base station device 101, for example, of UE Capability including the above-described FeatureSetsPerBands. The communication control unit 1202 receives, from the base station device 101, control information on the configuration of the CCs to be used for communication (such as the number of MIMO layers and information that can identify whether a separate circuit or a shared circuit should be used in the communication), based on the information notified to the base station device 101 by the capability information notifying unit 1201. The communication control unit 1202 can receive the control information, for example, via the above-described RRC Reconfiguration message. The communication control unit 1202 performs reception processing of signals transmitted in the multiple CCs in accordance with the control information.

[0054] FIG. 13 shows an example of the functional configuration of the base station device 101. The base station device 101 includes, for example, a capability information receiving unit 1301, a configuration determining unit 1302, and a configuration notifying unit 1303. Note that FIG. 13 only shows functions particularly related to this embodiment, and omits other functions that the base station device 101 may have. For example, the base station device 101 naturally has other functions that a base station device 101 conforming to LTE, 5G, or subsequent standards generally has. The functional blocks in FIG. 13 are shown schematically, and the functional blocks may be integrated or further subdivided. Each function in FIG. 13 may be implemented, for example, by the processor 1101 executing a program stored in the ROM 1102 or the storage device 1104, or by a processor within the communication circuit 1105 executing predetermined software. Since the details of the processing performed by each functional unit are as described above, only the general functions of the base station device 101 will be outlined here.

[0055] The capability information receiving unit 1301 receives capability information transmitted from the capability information notifying unit 1201 of the terminal device 102. The configuration determining unit 1302 determines a combination of the number of MIMO layers to be used in each CC in communication with the terminal device 102, based on the information received by the capability information receiving unit 1301. Furthermore, the configuration determining unit 1302 may determine whether the terminal device 102 should use a separate circuit or a shared circuit in communication with the combination of the number of MIMO layers to be used in each CC, or may specify performance requirements when signals of each CC are received in the terminal device 102. The configuration determining unit 1302 may specify the circuit to be used and the performance requirements depending on, for example, whether each CC is provided only by its own device or by its own device and another base station device, or may perform such specification based on measurement results in the terminal device 102 of signals from each CC. Furthermore, the configuration determining unit 1302 may identify the circuit to be used and performance requirements according to the measurement results using the antenna of the source of each CC of the signal transmitted from the terminal device 102, the setting value of the timing advance value, etc. The configuration notifying unit 1303 notifies the terminal device 102 of the configuration determined by the configuration determining unit 1302.

[0056] An example of the flow of processing executed in a wireless communication system is shown in Fig. 14. Note that, since the details of each process are as described above, only an overview of the processing flow will be given here, and detailed description will not be repeated.

[0057] In this processing example, first, the terminal device 102 transmits capability information (UE Capability) to the base station device 101, the capability information including information on combinations of the number of MIMO layers that the terminal device 102 can use for a plurality of CCs as described above, and information indicating a configuration to be used in the terminal device 102 or performance requirements that must be satisfied for processable signals when the number of MIMO layers indicated by the combinations is used in each of the plurality of CCs (S1401). The base station device 101 determines a combination of the number of MIMO layers to be used in each CC in communication with the terminal device 102 based on the capability information (S1402). Note that, in S1402, the base station device 101 can optionally specify whether the terminal device 102 should use a separate circuit or a shared circuit in communication with the combination of the number of MIMO layers to be used in each CC, or the performance requirements when the signal of each CC is received in the terminal device 102. Then, the base station device 101 transmits to the terminal device 102 an RRC Reconfiguration message including information on performance requirements related to received signals at the terminal device 102 between CCs used in dual connectivity or carrier aggregation determined in S1402, and information on configurations such as the circuit configuration to be used (S1403). The terminal device 102 starts reception processing with a combination of the number of MIMO layers to be used in multiple CCs based on the notified configuration information (S1404). Here, the terminal device 102 may perform reception processing using, for example, a circuit configuration (separate circuit or shared circuit) specified by the base station device 101, or may perform reception processing using a circuit configuration determined by the combination of the number of MIMO layers. Furthermore, when both a separate circuit and a shared circuit are available, the terminal device 102 may select and use either one.

[0058] As described above, in this embodiment, it is possible to identify the number of MIMO layers to be used in each CC in dual connectivity or carrier aggregation according to the configuration and performance of the receiving circuit of the terminal device 102. As a result, the base station device 101 can perform communication by appropriately selecting the MIMO configuration of each CC according to the capability of the terminal device 102. This makes it possible to contribute to Goal 9 of the Sustainable Development Goals (SDGs) led by the United Nations, which is to "Develop resilient infrastructure, promote sustainable industrialization and foster innovation."

[0059] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention.

Claims

1. A terminal device, Capability information of the terminal device, In dual connectivity or carrier aggregation, for each combination of component carriers (CCs) used in dual connectivity or carrier aggregation, information indicating a combination of the number of layers of multi-input multi-output (MIMO) in each of a plurality of CCs that can be used by the terminal device; In order to enable the terminal device to receive signals of the plurality of CCs with a predetermined quality when MIMO of the number of layers indicated by the combination is used in each of the plurality of CCs, information on performance requirements including at least one of a reception timing difference and a reception power difference that the received signal in the terminal device for each of the plurality of CCs should satisfy; a notification means for notifying a destination base station device of the capability information including the A control means for receiving control information including information on the number of MIMO layers used in the plurality of CCs from the base station device, and controlling reception processing of signals in the plurality of CCs based on the control information; A terminal device comprising:

2. 2. The terminal device according to claim 1, wherein the information on the performance requirement is information indicating at least one of the reception timing difference and the reception power difference that can obtain a predetermined throughput value as the predetermined quality.

3. The information on the performance requirements includes information on the performance requirements when receiving processing for each signal of the plurality of CCs using a shared circuit that shares some of the circuits, and information on the performance requirements when receiving processing for each signal of the plurality of CCs using separate circuits that are different circuits. The terminal device described in claim 1.

4. The terminal device according to claim 1 , wherein the notification unit notifies the base station device of the information on the performance requirements by using FeatureSetsPerBands in UE Capability.

5. The control information further indicates whether the terminal device should perform reception processing for each of the signals of the plurality of CCs using a shared circuit that shares some of the circuits, or whether the reception processing should be performed using separate circuits that are different circuits. The terminal device according to claim 1, characterized in that it includes information indicating whether the reception processing should be performed using separate circuits that are different circuits.

6. The control information further includes information on requirements to be satisfied by at least one of a reception timing difference and a reception power difference of the received signal in the terminal device for each signal of the plurality of CCs. The terminal device according to claim 1.

7. The terminal device according to claim 1 , wherein the control unit receives the control information by an RRC Reconfiguration message.

8. A base station device, Capability information of the currently connected terminal device, In dual connectivity or carrier aggregation, for each combination of component carriers (CCs) used in dual connectivity or carrier aggregation, information indicating a combination of the number of layers of multi-input multi-output (MIMO) in each of a plurality of CCs that can be used by the terminal device; In order to enable the terminal device to receive signals of the plurality of CCs with a predetermined quality when MIMO of the number of layers indicated by the combination is used in each of the plurality of CCs, information on performance requirements including at least one of a reception timing difference and a reception power difference that the received signal in the terminal device for each of the plurality of CCs should satisfy; receiving means for receiving the capability information including the above from the terminal device; A determination means for determining a configuration of the number of MIMO layers used in the plurality of CCs based on the capability information; a notification means for notifying the terminal device of control information including the determined configuration; A base station device comprising:

9. 9. The base station device according to claim 8, wherein the information on the performance requirement is information indicating at least one of the reception timing difference and the reception power difference that can obtain a predetermined throughput value as the predetermined quality.

10. The information on the performance requirements includes information on the performance requirements when receiving processing for each signal of the plurality of CCs using a shared circuit that shares some circuits, and information on the performance requirements when receiving processing for each signal of the plurality of CCs using separate circuits that are different circuits. The base station device according to claim 8, characterized in that it includes:

11. 9. The base station apparatus according to claim 8, wherein the receiving means receives the information on the performance requirements included in FeatureSetsPerBands in UE Capability.

12. The control information further indicates whether the terminal device should perform reception processing for each of the signals of the plurality of CCs using a shared circuit that shares some of the circuits, or whether the reception processing should be performed using separate circuits that are different circuits. The base station device according to claim 8, characterized in that it includes information indicating whether the terminal device should perform reception processing for each of the signals of the plurality of CCs using a shared circuit that shares some of the circuits, or whether the reception processing should be performed using separate circuits that are different circuits.

13. The control information further includes information on requirements to be satisfied by at least one of a reception timing difference and a reception power difference of the received signal in the terminal device for each signal of the plurality of CCs. The base station apparatus according to claim 8.

14. The base station device according to claim 8, characterized in that the determination means determines the number of MIMO layers to be used in the plurality of CCs based on whether each of the signals of the plurality of CCs is transmitted from each of different antennas arranged at positions spaced apart by a predetermined distance or more.

15. The base station apparatus according to claim 8, wherein the determining means determines the number of MIMO layers used in the plurality of CCs based on measurement results of the signals of the plurality of CCs in the terminal apparatus.

16. The base station device according to claim 8, characterized in that the determination means determines the number of MIMO layers to be used in the plurality of CCs based on measurement results of signals transmitted from the terminal device at antennas from which the plurality of CCs are transmitted.

17. The base station apparatus according to claim 8 , wherein the notification unit notifies the terminal apparatus of the control information by an RRC Reconfiguration message.

18. A control method executed by a terminal device, comprising: Capability information of the terminal device, In dual connectivity or carrier aggregation, for each combination of component carriers (CCs) used in dual connectivity or carrier aggregation, information indicating a combination of the number of layers of multi-input multi-output (MIMO) in each of a plurality of CCs that can be used by the terminal device; In order to enable the terminal device to receive signals of the plurality of CCs with a predetermined quality when MIMO of the number of layers indicated by the combination is used in each of the plurality of CCs, information on performance requirements including at least one of a reception timing difference and a reception power difference that the received signal in the terminal device for each of the plurality of CCs should satisfy; notifying the base station device of the connection destination of the capability information including the receiving, from the base station device, control information including information on the number of MIMO layers used in the plurality of CCs, and controlling reception processing of signals in the plurality of CCs based on the control information; A control method comprising:

19. A control method executed by a base station device, Capability information of the currently connected terminal device, In dual connectivity or carrier aggregation, for each combination of component carriers (CCs) used in dual connectivity or carrier aggregation, information indicating a combination of the number of layers of multi-input multi-output (MIMO) in each of a plurality of CCs that can be used by the terminal device; In order to enable the terminal device to receive signals of the plurality of CCs with a predetermined quality when MIMO of the number of layers indicated by the combination is used in each of the plurality of CCs, information on performance requirements including at least one of a reception timing difference and a reception power difference that the received signal in the terminal device for each of the plurality of CCs should satisfy; receiving the capability information from the terminal device, the capability information including: determining a configuration of the number of MIMO layers used in the plurality of CCs based on the capability information; notifying the terminal device of control information including the determined configuration; A control method comprising:

20. A program for causing a computer to function as each of the means included in the terminal device according to any one of claims 1 to 7.

21. A program for causing a computer to function as each of the means included in the base station device according to any one of claims 8 to 17.

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