JP2014060707A - Communication device, communication system and communication control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication device, a communication system and a communication control method, capable of efficient allocation of a carrier having deteriorated quality.SOLUTION: A communication device 101 communicable with a plurality of opposite communication devices with a space multiplexing system includes: a communication unit 111 for receiving from an opposite communication device a communication quality value for each carrier between the communication device and the opposite communication device; and a control unit 117 for reducing a space multiplexing number in a carrier in which quality indicated by the communication quality value does not satisfy predetermined quality, as compared to a carrier that satisfies the predetermined quality.

Description

  The present invention relates to a communication device and a communication control method.

  As a communication system for improving communication performance, an LTE (Long Term Evolution) system, an iBurst system, an XGP (eXtended Global Platform) system, and the like are attracting attention. These systems can employ a technique called SDMA (Space Division Multiple Access) in order to increase the efficiency of use of radio resources (see, for example, Patent Document 1).

  In a system employing SDMA, a base station that is a communication device divides radio resources into a plurality of carriers (frequency bands) and allocates the same carrier in the same time slot to a plurality of communication terminals. In these systems, an adaptive array technique is employed so that signals transmitted on the same carrier do not interfere with each other. The base station can transmit a signal only to a desired communication terminal by beam forming and null steering using adaptive array technology. Also, the base station can extract a signal from a desired communication terminal even when receiving a plurality of signals transmitted on the same carrier. Since a plurality of communication terminals can use the same carrier in the same time slot, it is possible to improve the utilization efficiency of radio resources.

JP 2003-259430 A

  Communication between a base station and a communication terminal when noise such as a signal (external signal) from the outside (for example, another base station) transmitted in the same frequency band as a carrier used for a plurality of communication terminals exists Will interfere with external signals. The same carrier may be used by a plurality of communication terminals, and the carrier is easily affected by external interference (external interference), and the communication quality of the carrier is likely to be deteriorated.

  In such a case, the conventional base station disables the carrier receiving external interference or continues to use all the carriers regardless of the occurrence of external interference. However, if a carrier that has undergone external interference is not used, there is a risk of shortage of radio resources. Also, regardless of the occurrence of external interference, if all carriers are equally allocated to communication terminals, the performance (throughput) of the carrier receiving external interference is significantly lower than that of the carrier not receiving external interference. End up.

  Accordingly, an object of the present invention made in view of the above problems is to provide a communication device, a communication system, and a communication control method capable of efficiently allocating a carrier having a reduced quality.

  In order to solve the above-described problems, the invention of the communication device according to the first aspect is a communication device capable of communicating with a plurality of partner communication devices by a spatial multiplexing method. A communication unit that receives a communication quality value for each carrier with a communication device, and a spatial multiplexing number in a carrier in which the quality indicated by the communication quality value does not satisfy a predetermined quality is a carrier that satisfies the predetermined quality. It is a communication apparatus provided with the control part reduced compared with.

  The invention according to a second aspect is the communication apparatus according to the first aspect, wherein when the control unit assigns a random access channel to the counterpart communication apparatus, the carrier that does not satisfy the predetermined quality can be used. By reducing the time, the number of spatial multiplexing in the carrier is reduced.

  Further, the invention according to a third aspect is the communication apparatus according to the second aspect, wherein the controller is configured such that the lower the quality indicated by the communication quality value of the carrier that does not satisfy the predetermined quality, the lower the carrier This is characterized in that the usable time of the system is shortened.

  The invention according to a fourth aspect is the communication apparatus according to the second or third aspect, wherein the control unit transmits the signal indicating the usable time for each carrier to the counterpart communication apparatus. The communication unit is controlled.

  As described above, the solution of the present invention has been described as an apparatus. However, the present invention can be realized as a method, a program, and a storage medium storing the program, which are substantially equivalent thereto, and the scope of the present invention. It should be understood that these are also included.

  For example, a communication system according to a fifth aspect that realizes the present invention as a communication system is a communication system in a communication apparatus capable of communicating with a plurality of counterpart communication apparatuses by a spatial multiplexing method, and the counterpart communication apparatus includes: A calculation unit that calculates a communication quality value for each carrier with the communication device; and a communication unit that transmits the communication quality value calculated by the calculation unit to the communication device. Communication means for receiving the communication quality value for each carrier between the counterpart communication device and the communication device from a device, and the number of spatial multiplexing in a carrier in which the quality indicated by the communication quality value does not satisfy a predetermined quality And a control means for reducing the amount of the carrier as compared with the carrier satisfying the predetermined quality.

  For example, a communication control method according to a sixth aspect that realizes the present invention as a method is a communication control method in a communication apparatus capable of communicating with a plurality of counterpart communication apparatuses by a spatial multiplexing method, and the communication apparatus Receiving a communication quality value for each carrier between the counterpart communication apparatus and the communication apparatus from the counterpart communication apparatus; and a spatial multiplexing number in a carrier in which the quality indicated by the communication quality value does not satisfy a predetermined quality. And a step of reducing the number of carriers as compared with a carrier satisfying the predetermined quality.

  According to the communication apparatus, the communication system, and the communication method according to the present invention configured as described above, it is possible to efficiently allocate a carrier having a reduced quality.

FIG. 1 is a schematic configuration diagram of a communication system according to an embodiment of the present invention. FIG. 2 is a functional block diagram showing a schematic configuration of a base station (communication device) according to an embodiment of the present invention. FIG. 3 is a flowchart showing processing of the base station (communication device) according to the embodiment of the present invention. FIG. 4 is an explanatory diagram showing carrier usage restrictions. FIG. 5 is an explanatory diagram showing carrier allocation. FIG. 6 is an explanatory diagram showing carrier usage restrictions. FIG. 7 is an explanatory diagram showing carrier allocation.

  Hereinafter, an embodiment in which a communication apparatus of the present invention is applied to a base station will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a communication system according to an embodiment of the present invention. The communication system 100 includes a base station 101 and communication terminals 103 (103a, 103b, 103c, 103d). The communication system 100 is a system that employs a spatial multiplexing method, and is, for example, an LTE system or an iBurst system. The base station 101 can communicate with the communication terminal 103 by a spatial multiplexing method. Spatial multiplexing is a technique in which the base station 101 can assign the same carrier (frequency band) in the same time slot to a plurality of communication terminals 103, for example, SDMA or PDMA (Path Division Multiple Access: path division multiple access). ). The number of communication terminals to which the same carrier is assigned in the same time slot means the number of spatial multiplexing, and the number of spatial multiplexing depends on the number of antennas, the performance of a processor responsible for signal processing, and the like. For example, in an iBurst system using 12 antennas, the maximum spatial multiplexing number is 3.

  The communication terminal 103 is a partner communication device that wirelessly communicates with the base station 101, such as a mobile phone terminal or a personal computer. Since the communication terminal 103 is located in the cell (communication area) 105 of the base station 101, it can wirelessly communicate with the base station 101. In FIG. 1, four communication terminals 103 are shown, but the present invention is not limited to this mode. For example, the number of communication terminals 103 can be two or more.

  FIG. 2 is a functional block diagram showing a schematic configuration of the base station 101 according to the first embodiment of the present invention. The base station 101 according to the present embodiment includes a communication unit 111, a baseband unit 113, a storage unit 115, and a control unit 117 as a control unit. The communication unit 111, the baseband unit 113, and the storage unit 115 are connected to the control unit 117.

  The communication unit 111 transmits and receives data (wireless signals) to and from the communication terminal 103 via an antenna. The communication unit 111 performs amplification and down-conversion with low noise on the received signal (reception signal) and sends the signal to the baseband unit 113. In addition, the communication unit 111 performs up-conversion and amplification on the signal from the baseband unit 113, and generates a transmission signal. Then, the communication unit 111 transmits the transmission signal to the communication terminal 103 via the antenna. Note that there are a plurality of antennas that can realize directivity control including beam forming and null steering, and are, for example, adaptive array antennas.

  The baseband unit 113 demodulates the received signal and extracts the baseband signal by performing AD conversion, fast Fourier transform, and the like on the received signal from the communication unit 111. Then, the baseband unit 113 sends a baseband signal to the control unit 117. In addition, the baseband unit 113 performs inverse fast Fourier transform, DA conversion, and the like on the baseband signal from the control unit 117 to modulate the baseband signal. Then, the baseband unit 113 sends the modulated baseband signal to the communication unit 111.

  The storage unit 115 stores various types of information, and also functions as a work memory.

  The control unit 117 controls and manages the entire base station 101 including each functional block of the base station 101. The control unit 117 is configured as software executed on an arbitrary suitable processor such as a CPU (central processing unit) or a dedicated processor (for example, DSP (digital signal processor)) specialized for each process. You can also. The processing performed by the control unit 117 will be described in detail with reference to FIG.

  Next, processing of the base station 101 will be described using FIG. FIG. 3 is a flowchart showing processing of the base station 101 according to an embodiment of the present invention. Hereinafter, it is assumed that base station 101 allocates a random access channel to communication terminal 103 and communicates with communication terminal 103. In the present embodiment, for convenience of explanation, it is assumed that there are four carriers (carriers C1 to C4) as shown in FIG. The random access channel is an uplink common channel from the communication terminal 103 to the base station 101, and the communication terminal 103 to which the random access channel is assigned randomly selects one of the four carriers, A signal is transmitted to the base station 101.

  First, the calculation means of the communication terminal 103 calculates a communication quality value for each carrier between the communication terminal 103 and the base station 101, and the communication means of the communication terminal 103 transmits the communication quality value to the base station 101. Then, the communication unit 111 of the base station 101 receives the communication quality value (step S101). The communication quality value may be transmitted by any one of the communication terminals 103a to 103d or a plurality of communication terminals. In addition, the present invention is not limited to a certain communication terminal 103 calculating communication quality values of all carriers and transmitting them to the base station 101. For example, the communication quality value of a different carrier may be calculated for each communication terminal, and the base station 101 may collect communication quality value information regarding all carriers by receiving the communication quality value from each communication terminal.

  The communication quality value indicates the influence of noise such as interference, and for example, noise level (noise floor), CINR (Carrier to Interference and Noise Ratio), SINR (Signal to Interference and Noise). Ratio: Signal to interference noise ratio), SNR (Signal to Noise Ratio), CNR (Carrier to Noise Ratio), and the like. The noise level is the value of noise itself including interference other than the desired wave, and the larger the value, the lower the quality of the communication environment. CINR or SINR means that the larger the value, the larger the ratio of the desired wave to noise (including interference), that is, the better the communication environment quality. Hereinafter, in this embodiment, it is assumed that the communication quality value is a noise level. That is, in step S101, the communication unit 111 of the base station 101 receives the noise level for each carrier.

  The control unit 117 performs the following determination process in step S103 for each carrier by the repetition process in step S102. First, the control unit 117 determines whether or not the quality of the carrier C1 indicated by the received communication quality value satisfies a predetermined quality (step S103). That is, the control unit 117 compares the communication quality value related to the carrier C1 with the communication quality threshold corresponding to the predetermined quality. When the communication unit 111 receives a plurality of communication quality values for each carrier, the control unit 117 can also compare the average value of the communication quality values for each carrier with the communication quality threshold value.

  The communication quality threshold is an index indicating an allowable noise intensity (level), and is a modulation method (for example, BPSK (Binary Phase Shift Keying), QPSK (Quadrature Phase Shift Keying) employed in the communication system 100. This is an item that is arbitrarily set according to the coding rate, the expected throughput, etc., and is stored in advance in the storage unit 115. In this embodiment, the communication quality value is a noise level, so the communication quality The threshold value is a threshold value related to the noise level, and is hereinafter referred to as a noise level threshold value.In this embodiment, the control unit 117 determines whether the quality indicated by the received noise level satisfies a predetermined quality. It is determined whether or not the noise level is less than a noise level threshold.

  When the noise level related to the carrier C1 is less than the noise level threshold (Yes in step S103), the control unit 117 can determine that the carrier C1 has a quality that can realize a desired communication performance. Therefore, the control unit 117 does not place restrictions on the use of the carrier C1.

  Subsequently, the control unit 117 compares the noise level related to the carrier C2 with the noise level threshold value (step S103). It is assumed that the noise level related to the carrier C2 is also less than the noise level threshold. Similarly, it is assumed that the noise level related to the carrier C3 is also less than the noise level threshold.

  And the control part 117 compares the noise level regarding the last carrier C4, and a noise level threshold value (step S103). It is assumed that the noise level related to the carrier C4 is equal to or higher than the noise level threshold. In this case (No in step S103), the control unit 117 can determine that the carrier C4 cannot achieve the desired communication performance. Therefore, the control unit 117 reduces the number of spatial multiplexing in the carrier C4 as compared with the carriers C1 to C3 that satisfy the predetermined quality.

  In the present embodiment, the control unit 117 shortens the time during which the communication terminal 103 can use the carrier C4 (usable time) compared to the carriers C1 to C3 that satisfy a predetermined quality in order to reduce the number of spatial multiplexing. (Step S104). That is, the control unit 117 limits the time during which the communication terminal 103 can use the carrier C4. As a result, a usable time and an unusable time exist in the carrier C4.

  For example, when the noise level related to the carrier C4 is equal to or higher than the noise level threshold, the control unit 117 can shorten the time during which the carrier C4 can be used by a predetermined amount (fixed value).

  Further, the control unit 117 can shorten the usable time of the carrier C4 as the quality indicated by the communication quality value is lower, that is, as the noise level is higher. For example, when the noise level related to the carrier C4 is greater than or equal to the noise level threshold and less than the first shortening threshold (> noise level threshold), the control unit 117 sets the usable time of the carrier C4 to ½ of the usable time of the carrier C1. If the noise level is not less than the first shortening threshold and less than the second shortening threshold (> first shortening threshold), the usable time of the carrier C4 can be reduced to ¼ of the usable time of the carrier C1. Moreover, the control part 117 can also change the usable time of the carrier C4 continuously according to the magnitude | size of a noise level like the following formula | equation (1), for example. Hereinafter, in the present embodiment, it is assumed that the control unit 117 changes the usable time of the carrier C4 in steps based on the first shortening threshold and the second shortening threshold.

(Usable time of carrier C4) = (Usable time of carrier C1) ×
(Noise level threshold) / (noise level of carrier C4) (1)
When the noise level related to the carrier C4 is not less than the noise level threshold and less than the first shortening threshold, the control unit 117 sets the usable time of the carrier C4 to ½ of the usable time of the carrier C1. For example, as shown in FIG. 4, the control unit 117 disables the carrier C4 in the time slots TS1 and TS3 that are half of the time slots TS1 to TS4. In FIG. 4, carriers C1 to C3 can be used in time slots TS1 to TS4 in order to satisfy a predetermined quality.

  When the determination processing in step S103 for all carriers is completed (step S105), the control unit 117 generates a signal indicating the usable time (usable time slot) for each carrier (step S106). And the control part 117 controls the baseband part 113 and the communication part 111 so that the said signal may be transmitted to the communication terminals 103a-103d (step S107).

  When receiving the signal indicating the usable time for each carrier, the communication terminals 103 a to 103 d randomly select a carrier that can be used for each time slot and transmit the signal to the base station 101. For example, as shown in FIG. 5, in time slot TS1, carrier C4 cannot be used, so communication terminals 103a and 103b use carrier C1, communication terminal 103c uses carrier C2, and communication terminal 103d Carrier C3 is used. Further, since all the carriers C1 to C4 can be used in the time slot TS2, the communication terminal 103a uses the carrier C3, the communication terminal 103b uses the carrier C2, the communication terminal 103c uses the carrier C4, The communication terminal 103d uses the carrier C1. In time slot TS3, carrier C4 cannot be used, so communication terminal 103a uses carrier C1, communication terminal 103b uses carrier C3, and communication terminals 103c and 103d use carrier C2. In the time slot TS4, all the carriers C1 to C4 can be used, so the communication terminal 103a uses the carrier C4, the communication terminal 103b uses the carrier C3, the communication terminal 103c uses the carrier C1, The communication terminal 103d uses the carrier C2.

  Since the use of the carrier C4 is limited by the noise level, the total number of communication terminals using the carriers C1, C2, C3, and C4 is 5, 5, 4 and 2 terminals, respectively.

  When the calculation means of the communication terminal 103 calculates the communication quality value for each carrier periodically or irregularly and transmits it to the base station 101, the base station 101 may repeat the processing from step S101 to step S107. it can. Thereby, the control part 117 can restrict | limit use of a carrier according to the change of communication environment.

  For example, after the time slot TS4, the carrier C4 is more strongly affected by external interference, and the noise level related to the carrier C4 is greater than or equal to the first shortened threshold and less than the second shortened threshold. In this case, the control unit 117 sets the usable time of the carrier C4 to ¼ of the usable time of the carrier C1. For example, the control unit 117 disables the carrier C4 in the three time slots TS5 to TS7 among the time slots TS5 to TS8 as shown in FIG. The carriers C1 to C3 can be used in the time slots TS5 to TS8 in order to satisfy a predetermined quality as in FIG.

  In the carrier use restriction shown in FIG. 6, for example, it is assumed that the communication terminals 103a to 103d use carriers as shown in FIG. In time slot TS5, carrier C4 cannot be used, so communication terminals 103a and 103b use carrier C1, communication terminal 103c uses carrier C2, and communication terminal 103d uses carrier C3. Similarly, since the carrier C4 cannot be used in the time slot TS6, the communication terminal 103a uses the carrier C3, the communication terminals 103b and 103d use the carrier C2, and the communication terminal 103c uses the carrier C1. . Similarly, since the carrier C4 cannot be used in the time slot TS7, the communication terminals 103a and 103c use the carrier C3, the communication terminal 103b uses the carrier C2, and the communication terminal 103d uses the carrier C1. . In the time slot TS8, all carriers C1 to C4 can be used, so the communication terminal 103a uses the carrier C2, the communication terminal 103b uses the carrier C3, the communication terminal 103c uses the carrier C1, The communication terminal 103d uses the carrier C4.

  Since the use of the carrier C4 is further restricted due to the deterioration of the quality of the carrier C4, the total number of communication terminals using the carriers C1, C2, C3 and C4 is 5, 5, 5 and 1 terminal, respectively. .

  Thus, in the present embodiment, the control unit 117 of the base station 101 reduces the number of spatial multiplexing in the carrier C4 whose noise level is equal to or higher than the noise level threshold compared to the carriers C1 to C3 whose noise level is lower than the noise level threshold. . Since the carrier C4 can be used under the restriction that the number of spatial multiplexing is reduced, the increase in the number of communication terminals using the carriers C1 to C3 can be suppressed as compared with the case where the carrier C4 is disabled at any time. Can do. As the number of communication terminals using the same carrier increases, signals from a plurality of communication terminals easily interfere with each other (hereinafter, interference between signals from communication terminals is referred to as internal interference). Therefore, if the carrier C4 is made unusable, the use of the carriers C1 to C3 is concentrated, and the influence of the internal interference of these carriers C1 to C3 becomes strong. In this embodiment, in the carrier C4 that is strongly influenced by external interference, the influence of internal interference is weakened due to the decrease in the number of spatial multiplexing, and in the carriers C1 to C3 that are weakly affected by external interference, internal interference is required due to continued use of the carrier C4 Do not increase more. Thereby, the performance of each carrier can be leveled. Further, since the carrier C4 can be used under the restriction that the number of spatial multiplexing is reduced, it is possible to prevent a reduction in radio resources. Therefore, efficient allocation of carriers with reduced quality is realized because it is difficult to cause performance degradation and lack of radio resources for each carrier.

  Moreover, in this embodiment, when assigning a random access channel to the communication terminal 103, the control unit 117 can shorten the usable time of the carrier C4 whose noise level is equal to or higher than the noise level threshold. Even if the communication terminal 103 randomly selects a carrier to be used for uplink communication with the base station 101, the carrier C4 cannot be selected depending on the time zone. As a result, the use frequency of the carrier C4 decreases, and the number of spatial multiplexing of the carrier C4 decreases.

  Further, in the present embodiment, when the noise level is equal to or higher than the noise level threshold, the control unit 117 can increase the reduction in the usable time of the carrier as the noise level increases. The control unit 117 can reduce the fluctuation of the carrier performance according to the noise level by reducing the spatial multiplexing number as the noise level is larger. In addition, even when the noise level changes due to a change in the communication environment, fluctuations in carrier performance can be reduced.

  In the present embodiment, the control unit 117 can control the communication unit 111 to transmit a signal indicating the usable time for each carrier to the communication terminal 103. The communication terminal 103 can grasp which carrier can be used from the signal indicating the usable time for each carrier. Therefore, it can be avoided that communication with the base station 101 fails due to signal transmission on a carrier that is not permitted to be used.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention.

  For example, functions included in each member, each means, each step, etc. can be rearranged so as not to be logically contradictory, and a plurality of means, steps, etc. can be combined or divided into one. Is possible.

  In the above description of the embodiments of the present invention, the communication device is a base station, but the present invention is not limited to this mode. For example, the communication device can be a relay device that relays signals transmitted and received between the base station and the communication terminal. The present invention can be applied when a relay apparatus adopting a spatial multiplexing scheme allocates a carrier to a communication terminal for communication between the communication terminal and the communication terminal.

  Controlling the number of spatial multiplexing for each carrier is not only performed based on the communication quality for each carrier as described above, but can also be applied to other situations. For example, when a carrier with a communication terminal having a high QoS (Quality of Service) requirement is used, the control unit of the base station can make the number of spatial multiplexing of the carrier smaller than other carriers. The control unit can use, for example, a QCI (QoS Class Identifier) parameter added to the signal in order to determine whether or not the QoS requirement is high. QCI defines communication quality required by a signal having QCI, and takes a value of 1 to 9. Each value defines a corresponding allowable delay time, an allowable data loss rate, and the like. When the QCI of the signal received by the base station is greater than or equal to a threshold value related to a preset QCI parameter, the control unit can determine that the QoS requirement of the communication terminal that has transmitted the signal is high. By reducing the number of spatial multiplexing of carriers used by communication terminals with high QoS requirements, it is possible to reduce internal interference in the carriers and maintain the communication quality of these carriers at a high level.

  Further, in the above description of the embodiment of the present invention, for example, the meaning of the technical idea of the expression such as the noise level threshold “greater than” or the noise level threshold “less than” is not necessarily a strict meaning. Depending on the specifications of the (base station), the meaning when the reference value is included or not included is included. For example, the noise level threshold “above” may imply not only when the noise level reaches the noise level threshold but also when the noise level exceeds the noise level threshold. Further, for example, the noise level threshold “less than” may imply not only when the noise level falls below the noise level threshold but also when the noise level threshold is reached, that is, when the noise level is below the noise level threshold. .

100 communication system 101 base station (communication device)
103a to 103d Communication terminal (other party communication device)
105 cells 111 communication unit 113 baseband unit 115 storage unit 117 control unit C1 to C4 carrier TS1 to TS8 time slot

Claims (6)

In a communication device capable of communicating with a plurality of partner communication devices by a spatial multiplexing method,
A communication unit that receives a communication quality value for each carrier between the counterpart communication device and the communication device from the counterpart communication device;
A communication apparatus comprising: a control unit that reduces the number of spatial multiplexing in a carrier whose quality indicated by the communication quality value does not satisfy a predetermined quality as compared with a carrier that satisfies the predetermined quality. The communication device according to claim 1,
The controller, when assigning a random access channel to the counterpart communication device, reduces the number of spatial multiplexing in the carrier by shortening the usable time of the carrier that does not satisfy the predetermined quality. Communication device. The communication device according to claim 2,
The control unit shortens the usable time of the carrier as the quality indicated by the communication quality value of the carrier that does not satisfy the predetermined quality is lower. The communication device according to claim 2 or 3,
The said control part controls the said communication part to transmit the signal which shows the usable time for every said carrier to the said other party communication apparatus, The communication apparatus characterized by the above-mentioned. A communication system in a communication device capable of communicating with a plurality of partner communication devices by a spatial multiplexing method,
The counterpart communication device is
A calculation unit that calculates a communication quality value for each carrier with the communication device, and a communication unit that transmits the communication quality value calculated by the calculation unit to the communication device,
The communication device
Communication means for receiving the communication quality value for each carrier between the counterpart communication device and the communication device from the counterpart communication device;
A communication system comprising: control means for reducing a spatial multiplexing number in a carrier whose quality indicated by the communication quality value does not satisfy a predetermined quality as compared with a carrier satisfying the predetermined quality. A communication control method in a communication device capable of communicating with a plurality of counterpart communication devices by a spatial multiplexing method, wherein the communication device is
Receiving a communication quality value for each carrier between the counterpart communication device and the communication device from the counterpart communication device;
A communication control method including a step of reducing a spatial multiplexing number in a carrier whose quality indicated by the communication quality value does not satisfy a predetermined quality as compared with a carrier satisfying the predetermined quality.

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