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

Abstract

To perform communication using multiple component carriers in an appropriate configuration according to the processing capacity of the terminal device. [Solution] In dual connectivity or carrier aggregation, the terminal device notifies the connected base station device of capability information, which includes, for each combination of component carriers (CCs) used in dual connectivity or carrier aggregation, information indicating the combination of Multi-Input Multi-Output (MIMO) layer counts for each of the multiple CCs available to the terminal device, and performance requirement information including at least one of the reception timing difference and reception power difference that the terminal device's received signal for each of the multiple CCs must satisfy in order to enable the terminal device to receive the signals of the multiple CCs with a predetermined quality when MIMO of the number of layers indicated by that combination is used for each of the multiple CCs.

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 Art

[0002] In the cellular communication standards of the Third Generation Partnership Project (3GPP (registered trademark)), technologies for performing communication using a plurality of component carriers (CCs, carrier waves), called dual connectivity (DC) and carrier aggregation (CA), are defined. In such communication using a plurality of CCs, it is assumed that communication performance will significantly deteriorate when the reception power difference between CCs is large, particularly when a single communication circuit in a terminal device processes the communication of those plurality of CCs. Patent Document 1 shows that when a single communication circuit is used in a terminal device, the deterioration of communication performance is significant, and when two communication circuits are used, even if the reception power difference between two CCs is relatively large, it is acceptable.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As the communication performed in each CC becomes more advanced, it is assumed that even if a terminal device simply has two communication circuits, the quality of communication using a plurality of CCs will significantly deteriorate. Also, even if a terminal device has only one communication circuit, it is assumed that with the improvement of the reception performance of the terminal device, the reception processing of signals via a plurality of CCs with a large transmission power difference can be performed with sufficient high quality.

Means for Solving the Problems

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

[0006] A terminal device according to one aspect of the present invention includes a notification means for notifying a connected base station device of the capability information of the terminal device, which includes capability information of the terminal device, which includes information indicating a combination of component carriers (CCs) used in dual connectivity or carrier aggregation, and information indicating a combination of MIMO layer counts that the terminal device can use in Multi-Input Multi-Output (MIMO) communication in each of the plurality of CCs included in the CC combination, and performance requirement information which includes conditions that must be satisfied with at least one of the reception timing difference and reception power difference between the signal received by the terminal device from the first CC among the plurality of CCs and the signal received by the terminal device from the second CC among the plurality of CCs, in order to enable the terminal device to receive the signals of the plurality of CCs with a predetermined quality when MIMO with the number of layers indicated by the information indicating the combination of layer counts is used in each of the plurality of CCs; and a control means for receiving control information from the base station device which includes information on the number of MIMO layers used in each of the plurality of CCs, and controlling the signal reception processing in the plurality of CCs based on the control information.

[0007] A base station device according to one aspect of the present invention includes: a receiving means for receiving capability information from a terminal device, which includes capability information of a connected terminal device, which includes: information indicating a combination of component carriers (CCs) used in dual connectivity or carrier aggregation, and a combination of MIMO layer counts that the terminal device can use in Multi-Input Multi-Output (MIMO) communication in each of the plurality of CCs included in the CC combination; and performance requirement information including conditions that must be satisfied with at least one of the reception timing difference and reception power difference between the signal received by the terminal device from the first CC among the plurality of CCs and the signal received by the terminal device from the second CC among the plurality of CCs, in order to enable the terminal device to receive the signals of the plurality of CCs with a predetermined quality when MIMO with the number of layers indicated by the information indicating the combination of layer counts is used in each of the plurality of CCs; a determining means for determining the configuration of the number of MIMO layers used in each of 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 becomes possible to perform communication using multiple component carriers in an appropriate configuration according to the processing capacity of the terminal device. [Brief explanation of the drawing]

[0009] [Figure 1] This is a diagram showing an example configuration of a wireless communication system. [Figure 2] This diagram shows an example of the configuration of a receiver in a terminal device. [Figure 3] This diagram shows an example of the configuration of a receiver in a terminal device. [Figure 4] This diagram shows an example of the configuration of a receiver in a terminal device. [Figure 5]This diagram shows an example of information that is notified from a terminal device to a base station device. [Figure 6] This diagram shows an example of information that is notified from a terminal device to a base station device. [Figure 7] This figure shows an example of a classification of terminal device types. [Figure 8] This diagram shows an example of information that is notified from a terminal device to a base station device. [Figure 9] This diagram shows an example of information that is notified from a terminal device to a base station device. [Figure 10] This diagram shows an example of information that is notified from a terminal device to a base station device. [Figure 11] This figure shows an example of the hardware configuration of terminal equipment and base station equipment. [Figure 12] This figure shows an example of the functional configuration of a terminal device. [Figure 13] This figure shows an example of the functional configuration of a base station device. [Figure 14] This diagram shows an example of the processing flow performed in a wireless communication system. [Modes for carrying out the invention]

[0010] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more of the features described in the embodiments may be combined in any way. Furthermore, identical or similar configurations will be given the same reference numeral, and redundant descriptions will be omitted.

[0011] Figure 1 shows an example of the configuration of the wireless communication system in this embodiment. This wireless communication system is a wireless communication system that conforms to the cellular communication standard of the Third Generation Partnership Project (3GPP®) and consists of a base station device 101 and a terminal device 102. The cellular communication standard may be, for example, Long-Term Evolution (LTE), 5th Generation (5G) New Radio (NR), or at least one of its successor standards. The terminal device 102 is configured to establish a connection with the base station device 101 and perform wireless communication. In this embodiment, the terminal device 102 is configured to communicate using multiple carriers using dual connectivity (DC) or carrier aggregation (AC). For example, in Figure 1, the terminal device 102 is configured 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 called component carriers (CC). In the following, the first carrier wave 111 may be referred to as the first CC, and the second carrier wave 112 may be referred to as the second CC. Two or more CCs may be contained in a common frequency band (any one of the 800MHz band, 2GHz band, 3.5GHz band, etc.), or each CC may be contained in a different frequency band. Furthermore, the terminal device 102 may be connected to one base station device 101, or to multiple base station devices 101. For example, the terminal device 102 may be connected to a first base station device that provides communication services on the first CC, while simultaneously being connected to a second base station device that provides communication services on the second CC.

[0012] To enhance communication in each of the multiple CCs, Multi-Input Multi-Output (MIMO) communication is expected to be implemented. In MIMO communication, communication is performed using multiple antennas provided on the base station device 101 and multiple antennas provided on the terminal device 102. In this embodiment, MIMO communication using N antennas in the base station device 101 and M antennas in the terminal device 102 may be called N×M MIMO. In this embodiment, as shown in Figure 1, one or more base station devices 101 communicate with the terminal device 102 using up to 4 antennas in the first CC, and also communicate with the terminal device 102 using up to 4 antennas in the second CC. In this case, for example, if the terminal device 102 has 8 antennas and corresponding communication processing circuits, it can use 4 antennas for each CC's communication and perform 4×4 MIMO communication for each CC. On the other hand, the terminal device 102 may be required to limit the number of antennas and the size of the circuits, and it is conceivable that it may not be able to have 8 antennas and circuits. Furthermore, if, for example, communication services by a first CC and a second CC are provided by separate base station equipment, the difference in received power and reception timing of signals transmitted by those CCs at the terminal equipment 102 may differ significantly. And, depending on whether the terminal equipment 102 can process the signals of multiple CCs with separate circuits, for example, the acceptable difference in received power and reception timing (the difference that allows sufficient suppression of interference between signals) may differ significantly. For this reason, if the base station equipment 101 does not have sufficient knowledge of the configuration of the terminal equipment 102, it may set up a MIMO configuration that prevents the terminal equipment 102 from communicating with sufficient quality. Also, if the base station equipment 101 does not have sufficient knowledge, it may unnecessarily suppress the use of MIMO communication even though the terminal equipment 102 can tolerate sufficiently large differences in received power and reception timing, thereby reducing the efficiency of communication.

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

[0014] Here, some configuration examples of the receivers that the terminal device 102 may have will be described using FIGS. 2 to 4. Note that FIGS. 2 to 4 show the configurations of the receivers of the terminal device 102 as mere examples, and receivers with configurations obtained by modifying the configurations of FIGS. 2 to 4 may be used, or receivers with configurations completely different from the configurations of FIGS. 2 to 4 may be used.

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

[0016] Figure 3 shows an example configuration where the antenna, diplexer, and LNA are shared by two systems. In this example, for example, two sets of iLNA, mixer, filter, and ADC, each handling signals from two CCs, share one set of antenna, diplexer, and LNA. When such sharing occurs, it is assumed that sufficient reception performance cannot be obtained unless the difference in reception timing and received power between the received signals at the two CCs is sufficiently small. In the configuration of Figure 3, for example, if 2x2 MIMO communication is performed at each of the two CCs, one set of iLNA, mixer, filter, and ADC, which shares 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 received power between the received signal at the first CC and the received signal at the second CC is relatively large. On the other hand, when 2x2 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, the remaining four receiving circuits, consisting of the two sets of antennas, diplexers, and LNAs, and two sets of iLNAs, mixers, filters, and ADCs that share the same combination, can be omitted. As a result, it is required that the difference in reception timing and received power between the received signal in the first CC and the received signal in the second CC be relatively small, but by performing communication within that range, the power consumption of the terminal device 102 can be suppressed.

[0017] Figure 4 shows an intermediate configuration between Figures 2 and 3, where two sets of antennas, diplexers, and LNAs are shared by two separate systems, and another two sets of antennas, diplexers, and LNAs are used by only one system. In this configuration, there are only six possible combinations of iLNAs, mixers, filters, and ADCs, so it is not possible to perform 4x4 MIMO communication in each of the two CCs. However, in this case, 4x4 MIMO and 2x2 MIMO communication can be performed in the two CCs, respectively. Here, since the two sets of antennas, diplexers, and LNAs are shared by two separate systems, it is assumed that sufficient reception performance cannot be obtained unless the difference in reception timing and received power between the received signals in the two CCs is sufficiently small. On the other hand, when 2x2 MIMO communication is performed in each of the two CCs, one of the two sets of iLNA, mixer, filter, and ADC that share one set of antenna, diplexer, and LNA does not need to be used. In this case, sufficient reception performance can be obtained even if the difference in reception timing and received power between the received signal in the first CC and the received signal in the second CC is relatively large. Alternatively, when 2x2 MIMO communication is performed in each of the two CCs, four receiving circuits can be used, consisting of two sets of antenna, diplexer, and LNA, and two sets of iLNA, mixer, filter, and ADC that share that combination. In this case, the receiving circuits of the remaining two sets (the two lower systems) of antenna, diplexer, LNA, iLNA, mixer, filter, and ADC can be left unused. As a result, it is required that the difference in reception timing and received power between the received signal in the first CC and the received signal in the second CC be relatively small. However, by performing communication within the range of this requirement, the power consumption of the terminal device 102 can be suppressed.

[0018] In the following, a receiving circuit in which the antenna, diplexer, and LNA are shared and used by multiple systems will be referred to as a shared circuit. Conversely, a receiving circuit in which the antenna, diplexer, and LNA are used by only one system will be referred to as a separate circuit, considering that each system is isolated. For example, the configuration in Figure 2 is called a separate circuit because, regardless of the type of communication performed between multiple CCs, the signals handled by each system are associated with only one CC. The configurations in Figures 3 and 4 are called shared circuits because, for example, when 4x4 MIMO communication is performed in at least one of the two CCs, at least one of the combinations of antenna, diplexer, and LNA is shared by multiple systems. On the other hand, the configurations in Figures 3 and 4 can be either a shared circuit or a separate circuit depending on the form of the circuit used when 2x2 MIMO communication is performed in each of the two CCs.

[0019] The terminal device 102 can, for example, notify the connected base station device 101 of information indicating whether communication using separate circuits and communication using shared circuits are possible in the 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 the two CCs, the terminal device 102 can notify the base station device 101 of whether communication can be performed using shared circuits or separate circuits.

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

[0021] When the base station device 101 receives information like that shown in Figures 5(A) to 5(C) from the terminal device 102, it can determine what configuration the terminal device 102 can use to communicate. For example, suppose the base station device 101 receives information like that shown in Figure 5(C) from the terminal device 102. In this case, the base station device 101 can determine that, for example, it cannot perform 4x4 MIMO communication with both CCs (the first CC and the second CC). Furthermore, the base station device 101 can determine that, provided that a shared circuit is used in the terminal device 102, it can perform 4x4 MIMO communication with one of the first CCs and 2x2 MIMO communication with the other. Also, the base station device 101 can determine that, regardless of whether a shared circuit or a separate circuit is used in the terminal device 102, it can perform 2x2 MIMO communication with both the first CC and the second CC.

[0022] Here, for example, suppose one base station device 101 communicates with a terminal device 102. In this case, if signals are transmitted at the same timing using the same power in the first CC and the second CC, it is assumed that the difference in reception timing and received 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 even if the terminal device 102 uses a shared circuit, it will be able to receive the signals from the first CC and the second CC with sufficient quality. For this reason, the base station device 101 assumes that the terminal device 102 can apply a shared circuit in such a case and can communicate with the terminal device 102 by selecting either a configuration in which only one of the first CC or the second CC uses 4x4 MIMO and the other uses 2x2 MIMO, or a configuration in which both the first CC and the second CC use 2x2 MIMO, which enables communication using a shared circuit. Furthermore, if the base station device 101 decides to use a configuration that employs 2x2 MIMO in 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, if, for example, communication in the first CC and communication in the second CC are provided by separate base station devices 101, it is conceivable that the reception timing difference and reception power difference between the received signal in the first CC and the received signal in the second CC will become large in the terminal device 102. In this case, if the multiple base station devices 101 can cooperate to sufficiently reduce the reception timing difference and reception power difference, it is conceivable that the terminal device 102 can communicate 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, the communication quality may deteriorate if the terminal device 102 uses a shared circuit. For this reason, a base station device 101 providing communication in either CC (e.g., a master base station) may decide to have the terminal device 102 use a separate circuit, for example, by deciding to use a configuration that uses 2x2 MIMO in both the first CC and the second CC.

[0024] In this way, the terminal device 102 can notify the base station device 101 of information indicating whether a separate circuit or a shared circuit can be used when performing MIMO communication with multiple CCs. This allows the base station device 101 to determine the number of MIMO layers (such as 4x4 or 2x2) to be used for each of the multiple CCs, taking into account the configuration of the receiver of the terminal device 102. Although the above example described the case where two CCs are used, three or more CCs may also be considered. For example, as shown in Figures 6(A) to 6(C), when either 4x4 MIMO or 2x2 MIMO is used for each of the 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 separate circuit. In this example, Figure 6(A) corresponds to the configuration in Figure 2, Figure 6(B) corresponds to the configuration in Figure 3, and Figure 6(C) corresponds to the configuration in Figure 4. When three CCs are used, the configurations in Figures 2 to 4 allow for a maximum of eight signal processing streams. Therefore, configurations where the total number of streams exceeds eight, such as when 4x4 MIMO is used in two or more of the three CCs, are not described. The terminal device 102 can, of course, have a receiving circuit capable of processing more than eight streams. Depending on the configuration, information regarding the availability of 4x4 MIMO for each of the three or more CCs may be notified to the base station device 101. Figures 5(A) to 5(C) and 6(A) to 6(C) only show the number of MIMO layers in each CC and whether communication is possible at that layer, but this is not the only option. For example, information such as whether a particular combination of CCs can be processed using a shared circuit, but other combinations cannot be processed even with a shared circuit, may be notified from the terminal device 102 to the base station device 101. For example, at least one of the following may be notified from the terminal device 102 to the base station device 101: 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.

[0025] Furthermore, for each of the configurations shown in Figures 2 to 4, the type of 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. Figure 7 shows an example of information indicating the receiver type of the terminal device 102. In Figure 7, UE Type=1 corresponds to a configuration in which four receiving circuits (eight circuits in total) are available for each of the two CCs, and these receiving circuits share not only the antenna and LNA but also the mixer. UE Type=2 corresponds to a configuration in which two receiving circuits (four circuits in total) are provided for each CC, and each has a separate antenna. That is, UE Type=2 corresponds to the configuration in Figure 2 where there are four circuits. Similarly, UE Type=3a corresponds to the configuration in Figure 4, UE Type=3b corresponds to the configuration in Figure 3, UE Type=4a corresponds to the configuration in Figure 2 where there are four circuits, and UE Type=4b corresponds to the configuration in Figure 2. The terminal device 102 can notify the base station device 101 of the configuration of its receiver, which of the UE Types 1 to 4b it is. Note that the configurations and UE Types shown in Figures 2 to 4 are examples, and for example, in the above example, one antenna is associated with one diplexer and one LNA, but the configuration is not limited to this. For example, one antenna may be associated with two or more diplexers or LNAs and subsequent circuits, or two antennas may be associated with one diplexer or LNA and subsequent circuits. Also, for example, multiple digital baseband processing circuits may be provided that are connected to the downstream of the configuration shown in Figures 2 to 4. Here, one digital baseband processing circuit may process only one CC, or it may process multiple CCs. Also, multiple digital baseband processing circuits may be configured to process a single CC. In this case, when determining whether the above-mentioned shared circuit is usable, it may be considered whether the digital baseband processing circuit can be shared for communication processing of multiple CCs.

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

[0027] For example, performance requirements can be defined by the Maximum Receive Timing Difference (MRTD), which indicates the maximum difference in reception timing between CCs, or by the maximum value of the Power Imbalance between CCs. For instance, a performance requirement where the allowable MRTD is 33 microseconds (μs) and the allowable power imbalance is 25 dB is called performance requirement A. Similarly, a performance requirement where the allowable MRTD is 3 μs and the allowable power imbalance is 6 dB is called performance requirement B. Performance requirement B is expected to be achieved, for example, when the same base station equipment provides communication using multiple CCs, or when multiple base station equipment located at the same location provides communication using different CCs. Performance requirement A is expected to be achieved even when multiple base station equipment located at different locations provides communication using different CCs. In addition to performance requirements A and B, other requirements may be provided, for example, where the MRTD is greater than 3 μs and less than 33 μs, or the maximum power imbalance is greater than 6 dB and less than 25 dB. Additionally, other requirements may be provided, such as MRTD being less than 3μs or greater than 33μs, or the maximum received power difference being less than 6dB or greater than 25dB. Furthermore, values ​​such as 3μs, 33μs, 6dB, and 25dB are examples, and different values ​​may be used to define performance requirements. Also, while MRTD may be used as a performance requirement for downlink dual connectivity or carrier aggregation, for uplink dual connectivity or carrier aggregation, Maximum uplink transmission timing difference (MTTD) may be used as the performance requirement instead of MRTD.

[0028] The terminal device 102 can notify the base station device 101 of information indicating which performance requirements must be met for each combination of MIMO layer counts in each CC to enable communication of sufficient quality. Figures 8(A) to 8(C) show examples of the performance requirement information notified in this case. Figure 8(A) corresponds to the configuration in Figure 2, Figure 8(B) to the configuration in Figure 3, and Figure 8(C) to the configuration in Figure 4. In the examples in Figures 8(A) to 8(C), performance requirement A is met when communication can be performed using a separation circuit, and performance requirement B is met when communication cannot be performed using a separation circuit but can be performed using a shared circuit. The terminal device 102 having the configuration in Figure 2 can perform communication using a separation circuit for each combination of MIMO layer counts in the CC, and can perform communication of sufficient quality if "performance requirement A" is met for each configuration. Therefore, as shown in Figure 8(A), such a terminal device 102 notifies the base station device 101 of information indicating "Performance Requirement A" as performance requirement information corresponding to each combination. Furthermore, a terminal device 102 having the configuration of Figure 3 can communicate using a shared circuit for each combination of MIMO layer counts in the CC, and can also communicate using a separate circuit when 2x2 MIMO communication is performed in both the first CC and the second CC. In other words, if "Performance Requirement A" is met for combinations in which both the first CC and the second CC use 2x2 MIMO, communication can be performed with sufficient quality, and if "Performance Requirement B" is met for other combinations, communication can be performed with sufficient quality. Therefore, such a terminal device 102 notifies the base station device 101 of performance requirement information corresponding to each combination, as shown in Figure 8(B). Furthermore, a terminal device 102 having the configuration of Figure 4 cannot communicate when 4x4 MIMO is used in the two CCs, but can perform the same processing as the terminal device 102 having the configuration of Figure 3 in other configurations. Therefore, such a terminal device 102 notifies the base station device 101 of the performance requirements corresponding to each combination, as shown in Figure 8(C).

[0029] It should be noted that the relationship between the configuration of the terminal device 102 and the performance requirements for enabling communication with sufficient quality, as described above, is merely an example. That is, even with a terminal device 102 having a configuration like that shown in Figure 2, communication using a shared circuit can be enabled by using a common digital baseband processing circuit for the received signals of multiple CCs. Even if a shared circuit is used, the terminal device 102 may be configured such that communication with sufficient quality is possible under requirements that are relaxed from performance requirement B (e.g., performance requirement A) through the advancement of that circuit. Regardless of the configuration shown in Figures 2 to 4, the terminal device 102 can notify the base station device 101 of the performance requirements (e.g., at least one of the received timing difference and the received power difference) that must be met in order to enable communication using a given combination of MIMO layers for each of the multiple CCs with a predetermined communication quality.

[0030] Furthermore, Figures 8(A) to 8(C) show the performance requirements that the terminal device 102 must satisfy when performing communication. When these performance requirements are met, or when stricter requirements are met, the terminal device 102 can perform communication at a predetermined quality. In other words, if the terminal device 102 can communicate at a predetermined quality when performance requirement A is met for each of the multiple CCs in a predetermined combination of MIMO layers, it can also communicate at a predetermined quality when performance requirement B is met. Therefore, when the base station device 101 receives information such as that shown in Figure 8(A), for example, it does not need to know whether the terminal device 102 is using an isolated circuit or a shared circuit, but it can recognize that if performance requirement A or a stricter requirement is met, the terminal device 102 can receive the signal at a predetermined quality.

[0031] For example, instead of the information shown in Figures 8(A) to 8(C), information regarding performance requirements for enabling the reception of signals with a predetermined quality in communication using both the isolated circuit and the shared circuit may be notified from the terminal device 102 to the base station device 101, as shown in Figures 9(A) to 9(C).

[0032] Furthermore, while Figures 8(A) to 8(C) and 9(A) to 9(C) show examples of cases where information about two CCs is notified, similar information may be notified when three or more CCs are available. For example, as shown in Figures 6(A) to 6(C), combinations of MIMO layer counts for three CCs are defined, and performance requirements that enable communication of a predetermined quality when that combination is used may be notified. For example, in the information corresponding to Figure 6(B), if 4x4 MIMO is used in one of the first to third CCs and 2x2 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 2x2 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. Therefore, for example, information such as performance requirement B for the first CC and the second CC, and performance requirement A for the third CC may be notified from the terminal device 102 to the base station device 101. Furthermore, separate information may be notified depending on which of the first, second, or third CCs the isolation circuit is used for. For example, FeatureSetsPerBands, described later, may notify for three patterns: when the isolation circuit is used for the first CC, when the isolation circuit is used for the second CC, and when the isolation circuit is used for the third CC. Furthermore, for example, when three CCs are used, five patterns can be considered: Pattern 1, where the received signals of all three CCs are processed by a common shared circuit; Pattern 2, where the first and second CCs are processed by a shared circuit and the third CC is processed by a separate circuit; Pattern 3, where the first and third CCs are processed by a shared circuit and the second CC is processed by a separate circuit; Pattern 4, where the second and third CCs are processed by a shared circuit and the first CC is processed by a separate circuit; and Pattern 5, where the first through third CCs are each processed by separate circuits.Here, for each combination of MIMO layer counts used in multiple CCs, information regarding the performance requirements for each of these five patterns may be notified from the terminal device 102 to the base station device 101. For example, for each pattern, information regarding the performance requirements between two of the three CCs may be notified. That is, three performance requirements may be notified for each pattern: the performance requirements between the first CC and the second CC, the performance requirements between the first CC and the third CC, and the performance requirements between the second CC and the third CC. In addition, for each combination of MIMO layer counts used in multiple CCs, a bitmap indicating whether each of these five patterns is usable may be notified. That is, whether communication is possible with patterns 1 to 5 may be indicated by 5 bits of information. In one example, the bitmap "11110" may indicate that communication is possible with patterns 1 to 4, but not with pattern 5. Such a bitmap may be notified for each combination of MIMO layer counts used in multiple CCs. Furthermore, a first bitmap showing patterns that enable communication when performance requirement A is met, and a second bitmap showing patterns that enable communication when performance requirement B is met may be notified to the base station device 101. Furthermore, when three or more CCs are used, the terminal device 102 may notify the base station device 101 only of the CC combinations that can satisfy performance requirement A. Furthermore, for example, if a system such as one antenna / diplexer / LNA is branched into three or more systems and configured to process three or more CCs included in the signal received from one antenna, information regarding the requirements that enable the combined processing of those three or more CC signals 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) as defined in the cellular communication standard. In one example, the above information may be notified using FeatureSetsPerBands, which is an element of the Band Combination information included in UE Capability. For example, when information such as that shown in Figures 5(A) to 5(C) or 6(A) to 6(C) is notified, FeatureSetsPerBands may be configured to include, for example, information on the number of layers for each CC and information indicating whether the isolation circuit and the shared circuit can be used for each CC combination used in dual connectivity or carrier aggregation. Figure 10(A) shows an example of the information that may be included in FeatureSetsPerBands when, for example, information such as that shown in Figure 5(B) is notified. Furthermore, when information such as that shown in Figures 8(A) to 8(C) or 9(A) to 9(C) is notified, FeatureSetsPerBands may be configured to include, for example, information on the number of layers for each CC and the performance requirements (P / R) required when communicating for that combination of layer counts (for each isolated / shared circuit in the case of Figures 9(A) to 9(C)). Figure 10(B) shows an example of the information that may be included in FeatureSetsPerBands when information such as that shown in Figure 8(B) is notified. Note that for MIMO layer count combinations that cannot be communicated, information indicating that communication is not possible may be notified, or the notification of information regarding that combination may be omitted.

[0034] The predetermined quality to be achieved when performance requirements are met can be defined, for example, by a throughput value. For instance, the performance requirements may be defined by a throughput value (e.g., 80% of the theoretical value) that should be achieved when the received power difference is a predetermined value (e.g., 6 dB or 25 dB). Alternatively, the performance requirements may be defined by a throughput value (e.g., 80% of the theoretical value) that should be achieved when the received timing difference is a predetermined value (e.g., 3 μs or 33 μs).

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

[0036] Furthermore, the base station device 101 may, for example, measure the signals transmitted from the terminal device 102 to each CC and estimate the received power difference and received timing difference between CCs in the terminal device 102, or it may determine the received timing difference between CCs in the terminal device 102 based on the timing advance value for each CC set for the terminal device 102. In addition, if multiple CCs are provided by one base station device 101 or by multiple base station devices 101 located at the same location (or within a predetermined distance range that can be treated as being at the same location), the base station device 101 may estimate that the received power difference and received timing difference are less than or equal to a predetermined value, without relying on the measured values ​​of the signals in the terminal device 102, etc. On the other hand, if multiple CCs are provided by multiple base station devices 101 located at different locations (outside a predetermined distance range that cannot be treated as being at the same location), the base station device 101 may estimate that the received power difference and received timing difference are greater than or equal to a predetermined value, without relying on the measured values ​​of the signals in the terminal device 102, etc.

[0037] In addition to determining the MIMO configuration for each CC, the base station device 101 can also determine whether the terminal device 102 should use a separate circuit or a shared circuit. For example, if only one of either a separate circuit or a shared circuit is available for communication in the determined MIMO configuration, the choice of which circuit to use is uniquely determined. On the other hand, if both a separate circuit and a shared circuit are available for communication in the determined MIMO configuration, the base station device 101 may decide which one to use. For example, when a separate circuit is used, the power consumption increases because more circuit components must operate within the terminal device 102 compared to when a shared circuit is used. Therefore, the base station device 101 may decide to have the terminal device 102 use a shared circuit when it is necessary to operate the terminal device 102 in a more power-saving state. On the other hand, when a separate circuit is used, the reliability of communication can be improved, for example, by maintaining communication even if there is a large difference in reception timing or reception power due to a change in circumstances. Therefore, the base station device 101 may decide to have the terminal device 102 use a separate circuit when it is necessary to improve the reliability of communication. The base station device 101 may also notify the terminal device 102 of information indicating whether to use the isolated circuit or the shared circuit.

[0038] For example, if base station device 101 receives information like that shown in Figure 10(A) from terminal device 102, it may decide to use 4x4 MIMO for both the first CC and the second CC. In this case, base station device 101 may notify terminal device 102 of information specifying the number of MIMO layers for the first CC (maxMIMO-Layers) = 4, the number of MIMO layers for the second CC = 4, and the reception method = shared circuit. Note that in this case, the information regarding the reception method = shared circuit can be uniquely determined by the number of MIMO layers, so this information does not need to be notified to terminal device 102. Also, if base station device 101 decides to use 2x2 MIMO for both the first CC and the second CC, and decides to use a separate circuit, it may notify 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 reception method = separate circuit. Furthermore, if the base station device 101 decides that a shared circuit should be used, it may 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 reception method = shared circuit.

[0039] Furthermore, the base station device 101 may decide which of the two circuits to use, the terminal device 102, without deciding or notifying the terminal device 102 which of the two circuits to use. For example, as described above, the terminal device 102 may decide which of the two circuits to use, the two of

[0040] In addition, terminal device 102 may notify base station device 101 as capability information whether or not it has the capability to accept a specification of whether to use an isolated circuit or a shared circuit. Base station device 101 may notify terminal device 102 of information specifying which circuit to use if terminal device 102 has that capability. In another example, terminal device 102 may notify base station device 101 as capability information whether or not terminal device 102 has the capability to decide whether to use an isolated circuit or a shared circuit. Base station device 101 may notify terminal device 102 of information specifying which circuit to use if terminal device 102 does not have that capability.

[0041] Furthermore, although the above example described a case where two CCs are used, in the same manner, when three or more CCs are used, information on the MIMO layer count for each CC and information indicating the reception method can be notified from the base station device 101 to the terminal device 102. In this case as well, if the reception method of the terminal device 102 is uniquely determined by the combination of MIMO layer counts, information on the reception method does not need to be notified. The base station device 101 may use the pattern information described above as information indicating the reception method. That is, for example, if pattern 1 is specified, it indicates that the received signals of all three CCs should be processed by a common shared circuit. Also, if pattern 5 is specified, it indicates that the first CC to the third CC should each be processed by a separate circuit.

[0042] Furthermore, the base station device 101 may specify information indicating the performance requirements expected to be met in each CC and notify the terminal device 102 of this information. For example, when the base station device 101 communicates with the terminal device 102 using multiple CCs, it may notify the terminal device 102 of information indicating that the signals will be transmitted in such a way that the above-mentioned performance requirement B is met. Also, when other base station devices located at different locations (at least outside a predetermined distance range from the base station device) communicate with the terminal device 102 using separate CCs, the base station device 101 may notify the terminal device 102 of information indicating that the signals will be transmitted in such a way that the above-mentioned performance requirement A is met. 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, it may notify the terminal device 102 of information indicating that the signals will be transmitted in such a way that the above-mentioned performance requirement A is met. In other words, the base station device 101 may notify the terminal device 102 of information indicating that the signal will be transmitted in a manner that satisfies performance requirement A if the distance between the antennas of the signal source in each CC is greater than or equal to a predetermined distance, and may notify the terminal device 102 of information indicating that the signal will be transmitted in a manner that satisfies performance requirement B if the distance is not greater than the predetermined distance.

[0043] When terminal device 102 receives notification of such performance requirements, it selectively uses either an isolated circuit or a shared circuit to ensure that communication is performed with sufficient quality when the communication is performed in accordance with those performance requirements. For example, when terminal device 102 receives notification that a signal will be transmitted in accordance with performance requirement A, it receives the signal in a configuration that allows for the magnitude of the reception timing difference and reception power difference between CCs as defined in the performance requirements. For example, terminal device 102 receives the signal transmitted by each CC in accordance with performance requirement A by using an isolated circuit or a signal processing circuit that allows for communication in accordance with the performance requirements. Also, when terminal device 102 receives notification that a signal will be transmitted in accordance with performance requirement B, it can determine that the differences in reception timing differences and reception power differences of the signals transmitted from each of the multiple CCs are small. For this reason, terminal device 102 may, for example, use a shared circuit to perform communication. Furthermore, when an isolated circuit is available, terminal device 102 may decide to use a shared circuit when reducing power consumption is a priority, and to use an isolated circuit when it is a priority to perform communication between each CC with higher precision.

[0044] For example, suppose the base station device 101 provides communication services using both a first CC and a second CC, and receives information as shown in Figure 10(B) from the terminal device 102. In this case, the base station device 101 can assume that performance requirement B will be met because the difference in reception timing and received power of the signals of the two CCs at the terminal device 102 is expected to be sufficiently small. For this reason, the base station device 101 may decide to use 4x4 MIMO for both the first CC and the second CC. In this case, the base station device 101 may notify the terminal device 102 of information specifying the number of MIMO layers for the first CC (maxMIMO-Layers) = 4, the number of MIMO layers for the second CC = 4, and performance requirement = B (performance requirement B). Furthermore, if the base station device 101 decides to use 2x2 MIMO in both the first CC and the second CC under the same conditions, it may 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 performance requirement = B. In other words, since performance requirement B is satisfied 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 decide whether to use an isolated circuit that can process data even under performance requirement A, or a shared circuit that can process data even under performance requirement B. Note that the base station device 101 may choose not to notify the terminal device 102 of the performance requirement information if it allows the terminal device 102 to independently decide whether to use an isolated circuit or a shared circuit.

[0045] Furthermore, when the base station device 101 receives information such as that shown in Figures 9(A) to 9(C) from the terminal device 102, it may use performance requirement information to specify whether the terminal device 102 should use the isolated circuit or the shared circuit. For example, when the base station device 101 receives information such as that shown in Figure 9(B) from the terminal device 102, it can notify the terminal device 102 that it should use the isolated circuit by transmitting information to the terminal device 102 specifying the number of MIMO layers for the first CC = 2, the number of MIMO layers for the second CC = 2, and the performance requirement = A. Alternatively, when the base station device 101 receives information such as that shown in Figure 9(B) from the terminal device 102, it can notify the terminal device 102 that it should use the shared circuit by transmitting information to the terminal device 102 specifying the number of MIMO layers for the first CC = 2, the number of MIMO layers for the second CC = 2, and the performance requirement = B.

[0046] On the other hand, if 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 and received power of the two CC signals will be large at terminal device 102. For this reason, base station device 101 can assume that performance requirement B will not be met and that communication will be possible within the scope of performance requirement A. In this case, base station device 101 may decide to use 2x2 MIMO for both the first CC and the second CC. Then, base station device 101 may notify 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 performance requirement = A. In these cases, if the receiving configuration of terminal device 102 can be uniquely determined only by the number of MIMO layers in each CC, it is not necessary to notify terminal device 102 of the performance requirement information. For example, if 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 it is presumed that performance requirement B is met by specifying such a MIMO configuration.

[0047] In the example above, we described a case where two CCs are used, but similarly, when three or more CCs (carriers) are used, information on the number of MIMO layers for each CC and information indicating performance requirements can be notified from the base station device 101 to the terminal device 102. For example, if all three CCs are provided by the same base station device, it is expected that the differences in reception timing and received power of the signals from the three CCs will be sufficiently small. For this reason, the base station device 101 may instruct the terminal device 102 to process all the signals received from the three CCs using a common shared circuit. In this case, the base station device 101 may also notify the terminal device of information indicating that the signals will be transmitted so that all of the signals from the three CCs satisfy performance requirement B. Furthermore, if the first CC and the second CC are provided from the same base station device, and the third CC is provided from another base station device located at a different location, it is expected that the difference in reception timing and received power between the signals of the first CC and the second CC will be sufficiently small, while the difference in reception timing and received power between the signals of the third CC and the first CC, and between the third CC and the second CC, will be large. For this reason, the base station device 101 may instruct the terminal device 102 to process the signals of the first CC and the second CC using a shared circuit and the signals of the third CC using a separate circuit. In this case, information indicating that the signals from the first CC and the second CC will be transmitted in such a way that they satisfy performance requirement B, and the signal from the third CC will be transmitted in such a way that it satisfies performance requirement A, may be notified from the base station device 101 to the terminal device 102. Furthermore, if the first CC and the third CC are provided from the same base station device, and the second CC is provided from another base station device located at a different location, it is expected that the difference in signal reception timing and received power between the first CC and the third CC will be sufficiently small, while the difference in signal reception timing and received power between the second CC and the first CC, and between the second 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 first CC and the third CC using a shared circuit, and the second CC using a separate circuit.In this case, information indicating that the signals from the first CC and the third CC are transmitted in such a way that they satisfy performance requirement B, and the signal from the second CC is transmitted in such a way that it satisfies performance requirement A, may be notified from the base station device 101 to the terminal device 102. Furthermore, if 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 at a different location, it is expected that the difference in reception timing and received power between the signals of the second CC and the third CC will be sufficiently small, while the difference in reception timing and received power between the signals of the first CC and the second CC, and between 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 signals of the second CC and the third CC using a shared circuit and the signal of the first CC using a separate circuit. In this case, information indicating that the signals from the second CC and the third CC are transmitted in such a way that they satisfy performance requirement B, and the signal from the first CC is transmitted in such a way that it satisfies performance requirement A, may be notified from the base station device 101 to the terminal device 102. Furthermore, if the first to third CCs are all provided by different base station devices located in different positions, it is expected that the differences in reception timing and received power of all signals will be large. For this reason, the base station device 101 may instruct the terminal device 102 to process the first to third CCs using separate circuits. In this case, information indicating that the signals from the first to third CCs are transmitted in a manner that satisfies performance requirement A may be notified from the base station device 101 to the terminal device 102.

[0048] Furthermore, information regarding the performance requirements that the first to third CCs must satisfy 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 example above, the following patterns may be defined: Pattern 1, in which all three CC signals are transmitted to satisfy performance requirement B; Pattern 2, in which the signals of the first and second CCs satisfy performance requirement B, and the signal of the third CC satisfies performance requirement A; Pattern 3, in which the signals of the first and third CCs satisfy performance requirement B, and the signal of the second CC satisfies performance requirement A; Pattern 4, in which the signals of the second and third CCs satisfy performance requirement B, and the signal of the first CC satisfies performance requirement A; and Pattern 5, in which the signals of the first to third CCs are transmitted to satisfy performance requirement A in all combinations. Furthermore, the base station device 101 can notify the terminal device 102 of the pattern in which the signal will be transmitted (how the terminal device 102 should perform the reception processing).

[0049] In this case as well, if the receiving configuration of terminal device 102 is uniquely determined by the combination of MIMO layer counts, information regarding performance requirements does not need to be notified. Furthermore, although an example of treating each CC equally when three CCs are used has been described here, some combinations of CCs may be treated differently from others. For example, different treatment may be applied depending on the Radio Access Technology (RAT) used for each CC. For example, when CCs of three frequency bands, B42 (LTE: 3.5GHz band), n77L (NR: 3.8GHz-4.1GHz), and n77H (NR: 3.9GHz-4.2GHz), 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, so communication between them may always be treated as satisfying performance requirement B. On the other hand, since B42 is a carrier wave used by LTE base station equipment, the signals transmitted by this carrier wave may be transmitted from a different location than the NR base station equipment, and it may not always be appropriate to treat it as satisfying performance requirement B. For this reason, base station equipment 101 may not transmit any special instructions for n77L and n77H, but may transmit information to terminal equipment 102 that allows it to specify whether to use a shared circuit or a separate circuit for B42. Then, terminal equipment 102 may always use a shared circuit to receive the CC signals for n77L and n77H, and may selectively use either a shared circuit or a separate circuit for receiving the CC signals for B42, in accordance with instructions from base station equipment 101.

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

[0051] Figure 11 shows an example of the hardware configuration of a base station device 101 and a 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, ROM 1102, RAM 1103, storage device 1104, and 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 the overall control processing of the device and the above-mentioned processing by reading and executing programs stored in the ROM 1102 and the storage device 1104. The ROM 1102 is a read-only memory that stores information such as programs and various parameters related to the processing performed by the base station device 101 and the terminal device 102. The RAM 1103 functions as a workspace when the processor 1101 executes programs and is a random access memory that stores temporary information. The storage device 1104 is configured to include, for example, a removable external storage device. The communication circuit 1105 is composed of, for example, circuits for wireless communication of LTE, 5G, and subsequent standards. Although Figure 11 shows one communication circuit 1105, the base station device 101 and terminal device 102 may have multiple communication circuits. For example, the base station device 101 and terminal device 102 may have wireless communication circuits for LTE, 5G, and subsequent standards, respectively, and an antenna common to these circuits. The base station device 101 and terminal device 102 may also have separate antennas suitable for each standard. Furthermore, the base station device 101 may also have a wired communication circuit used when communicating with other base station devices or nodes of the core network. Furthermore, the terminal device 102 may also have communication circuits compliant with wireless communication standards other than cellular communication standards, such as wireless local area networks (LANs) and Bluetooth®. The base station device 101 and the terminal device 102 may have separate communication circuits 1105 for each of the multiple usable frequency bands, or they may have a common communication circuit 1105 for at least a portion of those frequency bands. The communication circuit 1105 of the terminal device 102 may include configurations such as those shown in Figures 2 to 4.

[0052] Figure 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 Figure 12 only shows functions particularly relevant to this embodiment, and other various 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. Also, the functional blocks in Figure 12 are shown schematically, and each functional block may be implemented as an integrated unit or further subdivided. Furthermore, each function in Figure 12 may be implemented, for example, by the processor 1101 executing a program stored in the ROM 1102 or storage device 1104, or by a processor located inside the communication circuit 1105 executing predetermined software. Note that the details of the processing performed by each functional unit are as described above, so only the general functions of the terminal device 102 will be outlined here.

[0053] The capability information notification unit 1201 notifies the base station device 101 of the above-mentioned information on the combination of MIMO layer counts for multiple CCs that the terminal device 102 can use, and information indicating the performance requirements that the configuration or signal that can be processed by the terminal device 102 should satisfy when the number of MIMO layers indicated by that combination are used in each of the multiple CCs. The capability information notification unit 1201 notifies the base station device 101 of the UE Capability, including the above-mentioned FeatureSetsPerBands, for example. Based on the information notified to the base station device 101 by the capability information notification unit 1201, the communication control unit 1202 receives control information from the base station device 101 regarding the configuration of the CCs used for communication (such as the number of MIMO layers and information that can identify whether to use an isolated circuit or a shared circuit in that communication). The communication control unit 1202 may receive this control information, for example, through an RRC Reconfiguration message as described above. The communication control unit 1202 performs reception processing of signals transmitted in the multiple CCs according to the control information.

[0054] Figure 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 determination unit 1302, and a configuration notification unit 1302. Note that Figure 13 shows only the functions particularly relevant to this embodiment, and various other functions that the base station device 101 may have are omitted from the illustration. For example, the base station device 101 naturally has other functions that a base station device 101 compliant with LTE, 5G, and subsequent standards generally has. Also, the functional blocks in Figure 13 are shown schematically, and each functional block may be implemented as an integrated unit or further subdivided. Furthermore, each function in Figure 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 located inside the communication circuit 1105 executing predetermined software. Note that the details of the processing performed by each functional unit are as described above, so 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 notification unit 1201 of the terminal device 102. Based on the information received by the capability information receiving unit 1301, the configuration determination unit 1302 determines the combination of MIMO layer counts to be used in communication with the terminal device 102. The configuration determination unit 1302 may also determine whether the terminal device 102 should use a separate circuit or a shared circuit in communication with the combination of MIMO layer counts to be used for each CC, or it may specify the performance requirements when the signals from each CC are received by the terminal device 102. For example, the configuration determination unit 1302 may specify the circuits to be used and the performance requirements depending on whether each CC is provided solely by its own device or by its own device and other base station devices, or it may make this determination based on the measurement results of the signals from each CC in the terminal device 102. Furthermore, the configuration determination unit 1302 may identify the circuits to be used and the performance requirements based on the measurement results using the source antenna of each CC of the signal transmitted from the terminal device 102, the set value of the timing advance value, etc. The configuration notification unit 1303 notifies the terminal device 102 of the configuration determined by the configuration determination unit 1302.

[0056] Figure 14 shows an example of the processing flow performed in a wireless communication system. Since the details of each process are described above, only a general overview of the processing flow will be provided here, and detailed explanations will not be repeated.

[0057] In this example, terminal device 102 first transmits to base station device 101 (S1401) capability information (UE Capability) that includes information on the combinations of MIMO layer counts that terminal device 102 can use for multiple CCs, as described above, and information indicating the performance requirements that the configuration or signals that terminal device 102 should satisfy should meet when the number of MIMO layers indicated by that combination are used in each of the multiple CCs. Based on this capability information, base station device 101 determines the combination of MIMO layer counts that should be used in each CC for communication with terminal device 102 (S1402). In addition, in S1402, base station device 101 may optionally specify whether terminal device 102 should use an isolated circuit or a shared circuit for communication with the combination of MIMO layer counts that should be used in each CC, or the performance requirements when the signals of each CC are received by terminal device 102. Then, the base station device 101 sends an RRC Reconfiguration message to the terminal device 102 containing information on the performance requirements for the received signals at the terminal device 102 between CCs used in dual connectivity or carrier aggregation determined in S1402, as well as configuration information such as the circuit configuration to be used (S1403). Based on the notified configuration information, the terminal device 102 starts receiving processing for the combination of MIMO layer counts to be used in the multiple CCs (S1404). Here, the terminal device 102 may, for example, perform receiving processing using the circuit configuration (separated circuit or shared circuit) specified by the base station device 101, or it may perform receiving processing using the circuit configuration determined by the combination of MIMO layer counts. Also, if both a separated circuit and a shared circuit are available, the terminal device 102 may select and use one of them.

[0058] As described above, in this embodiment, the number of MIMO layers to be used in each CC in dual connectivity or carrier aggregation can be determined according to the configuration and performance of the receiving circuit of the terminal device 102. As a result, the base station device 101 can appropriately select the MIMO configuration in each CC and communicate according to the capabilities of the terminal device 102. Thus, it becomes possible to contribute to Goal 9 of the United Nations Sustainable Development Goals (SDGs), "Build resilient infrastructure, promote sustainable industrialization and foster innovation."

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

Claims

1. A terminal device, The capability information of the aforementioned terminal device, In dual connectivity or carrier aggregation, the information indicates the combination of component carriers (CCs) used in dual connectivity or carrier aggregation, and also indicates the combination of MIMO layer counts that the terminal device can use in Multi-Input Multi-Output (MIMO) communication in each of the multiple CCs included in the CC combination, When MIMO with a number of layers indicated by information indicating the combination of the number of layers is used in each of the plurality of CCs, in order to enable the terminal device to receive the signals of the plurality of CCs with a predetermined quality, information on performance requirements that includes conditions that must be satisfied with at least one of the reception timing difference and the reception power difference between the signal received by the terminal device from the first CC among the plurality of CCs and the signal received by the terminal device from the second CC among the plurality of CCs, Notification means for notifying the base station equipment to which the capability information, including the above, is connected, Control means that receives control information from the base station device, including information on the number of MIMO layers used in each of the plurality of CCs, and controls the signal reception processing in the plurality of CCs based on said control information, A terminal device characterized by having the following features.

2. The terminal device according to claim 1, characterized in that the performance requirement information 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 terminal device according to claim 1, characterized in that the performance requirements information includes the performance requirements information when the reception processing for each of the multiple CC signals is performed using a shared circuit that shares an antenna, a diplexer, and a low-noise amplifier, and the performance requirements information when the reception processing for each of the multiple CC signals is performed using separate circuits which are different circuits.

4. The terminal device according to claim 1, characterized in that the notification means notifies the base station device of the performance requirements information using FeatureSetsPerBands in UE Capability.

5. The terminal device according to claim 1, further comprising information indicating whether the terminal device should perform the reception processing for each of the plurality of CC signals using a shared circuit that shares an antenna, a diplexer, and a low-noise amplifier, or whether the reception processing should be performed using separate circuits that are different circuits for each signal.

6. The terminal device according to claim 1, characterized in that the control means receives the control information by an RRC Reconfiguration message.

7. Base station equipment, Capability information of the connected terminal device, In dual connectivity or carrier aggregation, the information indicates the combination of component carriers (CCs) used in dual connectivity or carrier aggregation, and also indicates the combination of MIMO layer counts that the terminal device can use in Multi-Input Multi-Output (MIMO) communication in each of the multiple CCs included in the CC combination, When MIMO with a number of layers indicated by information indicating the combination of the number of layers is used in each of the plurality of CCs, in order to enable the terminal device to receive the signals of the plurality of CCs with a predetermined quality, information on performance requirements that includes conditions that must be satisfied with at least one of the reception timing difference and the reception power difference between the signal received by the terminal device from the first CC among the plurality of CCs and the signal received by the terminal device from the second CC among the plurality of CCs, A receiving means that receives the capability information including the above from the terminal device, A determination means for determining the configuration of the number of MIMO layers used in each of 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 characterized by having the following features.

8. The base station device according to claim 7, characterized in that the performance requirement information 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.

9. The base station device according to claim 7, characterized in that the performance requirements information includes the performance requirements information when the reception processing for each of the multiple CC signals is performed using a shared circuit that shares an antenna, a diplexer, and a low-noise amplifier, and the performance requirements information when the reception processing for each of the multiple CC signals is performed using separate circuits which are different circuits.

10. The base station device according to claim 7, characterized in that the receiving means receives information on the performance requirements included in FeatureSetsPerBands in UE Capability.

11. The base station device according to claim 7, further comprising information indicating whether the terminal device should perform the reception processing for each of the plurality of CC signals using a shared circuit that shares an antenna, a diplexer, and a low-noise amplifier, or whether the reception processing should be performed using separate circuits which are different circuits.

12. The base station device according to claim 7, characterized in that the determination means determines the number of MIMO layers 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 located at a predetermined distance or more apart.

13. The base station device according to claim 7, characterized in that the determination means determines the number of MIMO layers used in the plurality of CCs based on the measurement results in each of the terminal devices of the plurality of CCs.

14. The base station device according to claim 7, characterized in that the determination means determines the number of MIMO layers used in the plurality of CCs based on the measurement results at the source antennas of the plurality of CCs of the signal transmitted from the terminal device.

15. The base station device according to claim 7, characterized in that the notification means notifies the terminal device of the control information by an RRC Reconfiguration message.

16. A control method performed by a terminal device, The capability information of the aforementioned terminal device, In dual connectivity or carrier aggregation, the information indicates the combination of component carriers (CCs) used in dual connectivity or carrier aggregation, and also indicates the combination of MIMO layer counts that the terminal device can use in Multi-Input Multi-Output (MIMO) communication in each of the multiple CCs included in the CC combination, When MIMO with a number of layers indicated by information indicating the combination of the number of layers is used in each of the plurality of CCs, in order to enable the terminal device to receive the signals of the plurality of CCs with a predetermined quality, information on performance requirements that includes conditions that must be satisfied with at least one of the reception timing difference and the reception power difference between the signal received by the terminal device from the first CC among the plurality of CCs and the signal received by the terminal device from the second CC among the plurality of CCs, The capability information, including the above, is notified to the base station equipment to which it is connected. The base station device receives control information including information on the number of MIMO layers used in each of the multiple CCs, and controls the signal reception process in the multiple CCs based on said control information. A control method characterized by including

17. A control method performed by a base station device, Capability information of the connected terminal device, In dual connectivity or carrier aggregation, the information indicates the combination of component carriers (CCs) used in dual connectivity or carrier aggregation, and also indicates the combination of MIMO layer counts that the terminal device can use in Multi-Input Multi-Output (MIMO) communication in each of the multiple CCs included in the CC combination, When MIMO with a number of layers indicated by information indicating the combination of the number of layers is used in each of the plurality of CCs, in order to enable the terminal device to receive the signals of the plurality of CCs with a predetermined quality, information on performance requirements that includes conditions that must be satisfied with at least one of the reception timing difference and the reception power difference between the signal received by the terminal device from the first CC among the plurality of CCs and the signal received by the terminal device from the second CC among the plurality of CCs, Receiving the capability information including the above from the terminal device, Based on the capability information, the configuration of the number of MIMO layers used in each of the multiple CCs is determined, To notify the terminal device of the control information including the determined configuration, A control method characterized by including

18. A program for causing a computer to function as one of the means of a terminal device according to any one of claims 1 to 6.

19. A program for causing a computer to function as one of the means of a base station device according to any one of claims 7 to 15.

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