JP5673701B2 - Base station, communication terminal, base station communication method, communication terminal communication method, communication system - Google Patents

Description

  The present case relates to a base station, a communication terminal, a communication method of the base station, a communication method of the communication terminal, and a communication system. This case may be used for a wireless communication system having a communication terminal and a base station, for example.

  In Long Term Evolution (LTE), which is being standardized by the 3rd Generation Partnership Project (3GPP), and in the standard such as Worldwide Interoperability for Microwave Access (WiMAX), there are limited radio resources that can be used for radio communication. The radio resource includes, for example, a resource in the time axis direction (time slot) and a resource in the frequency axis direction (frequency resource or frequency band).

When multiple communication terminals communicate with a base station by radio, the base station optimizes radio resource allocation (scheduling) for each communication terminal and a communication method suitable for each communication terminal in order to prevent a decrease in communication efficiency. May be selected.
As an index for determining how to allocate radio resources, for example, the amount of transmission / reception data, Quality of Service (QoS), the propagation environment (quality) between the base station and the communication terminal, the number of communication terminals desired to transmit / receive to / from the base station ,and so on.

For example, the base station performs scheduling as illustrated in FIG. 12 based on the index. FIG. 12 shows an example in which data (user data and control information) addressed to the communication terminals A to C is allocated and transmitted to a two-dimensional radio resource (communication area) defined by a time slot and a frequency resource. Yes.
JP-A-2005-341176 JP-A-9-205396

However, in the prior art, radio resources can be allocated (scheduled) on the same basis for communication terminals having different battery levels.
One of the purposes of this case is to suppress battery consumption of the communication terminal by allocating radio resources based on the battery information of the communication terminal.
It should be noted that the present invention is not limited to the above-described object, and can be positioned as one of other objects that is an effect obtained by each configuration shown in the embodiments to be described later and that cannot be obtained by conventional techniques. .

For example, the following means are used.
(1) A base station that can communicate with a plurality of communication terminals, the receiving unit receiving information for controlling battery consumption of the communication terminal from the plurality of communication terminals, and receiving the information by the receiving unit A control unit that controls setting of radio resources including a plurality of transmission timings and frequency resources for data transmission addressed to the plurality of communication terminals, and the control unit suppresses battery consumption by the information. It is possible to use a base station that controls to reduce the number of transmission timings of data addressed to a communication terminal, which is a value indicating, and to increase frequency resources used for the data transmission .
( 2 ) Also, a base station that can communicate with a plurality of communication terminals, a receiving unit that receives information for controlling battery consumption of the communication terminal from the plurality of communication terminals, and the information received by the receiving unit And a control unit that controls setting of radio resources including a plurality of transmission timings of data transmission addressed to the plurality of communication terminals, and the control unit indicates that the information suppresses battery consumption The frequency resource used to transmit the data addressed to the communication terminal is controlled so as to decrease the number of transmission timings of the data addressed to the communication terminal, and the information does not indicate that the battery consumption is suppressed. A base station can be used that controls to increase.
( 3 ) A communication terminal capable of communicating with a base station, wherein the base station transmits information for controlling battery consumption of the communication terminal of the local station, and the base station transmits the information to the base station. A plurality of transmission timings and frequencies set to decrease the number of transmission timings of data addressed to a communication terminal that is received and the value indicating that the information suppresses battery consumption and to increase frequency resources used for the transmission of the data A communication terminal including a data receiving unit that receives data from the base station using radio resources including resources can be used.

( 4 ) In addition, a communication control method for a base station capable of communicating with a plurality of communication terminals, wherein when the information for controlling battery consumption of the communication terminal is received from the plurality of communication terminals, the information is consumed by the battery. A plurality of transmissions used for transmission of data addressed to the plurality of communication terminals so as to reduce the number of transmission timings of data addressed to the communication terminals and to increase the frequency resource used to transmit the data A base station communication method that controls the setting of radio resources including timing and frequency resources can be used.
( 5 ) Further, a communication control method of a communication terminal capable of communicating with a base station, wherein information for controlling battery consumption of the communication terminal of the local station is transmitted to the base station, and the base station transmits the information A plurality of transmission timings set to decrease the number of transmission timings of data addressed to a communication terminal, which is a value indicating that the information suppresses battery consumption, and to increase frequency resources used for transmission of the data; A communication method of a communication terminal that receives data from the base station using radio resources including frequency resources can be used.

( 6 ) Further, the communication system includes a plurality of communication terminals and a base station capable of communicating with the plurality of communication terminals, each of the plurality of communication terminals controlling battery consumption of the communication terminal of the local station. A transmission unit that transmits information for receiving the information, and the base station receives information for controlling battery consumption of the communication terminal from the plurality of communication terminals, and the reception unit receives the information. A control unit that controls setting of radio resources including a plurality of transmission timings and frequency resources for data transmission addressed to the plurality of communication terminals, and the control unit controls the information to suppress battery consumption. Use a communication system that controls to reduce the number of transmission timings of data addressed to a communication terminal, which is the value shown, and to increase the frequency resource used for transmitting the data It can be.

  It is possible to suppress battery consumption of the communication terminal.

It is a figure which shows the structural example of the radio | wireless communications system which concerns on one Embodiment. It is a figure which shows an example of the scheduling of the base station shown in FIG. It is a figure which shows an example of the response method of the communication terminal shown in FIG. It is a figure which shows an example of the parameter used for scheduling. It is a block diagram which shows the structural example of the base station shown in FIG. It is a block diagram which shows the structural example of the communication terminal shown in FIG. It is a figure which shows an example of the scheduling of the base station shown in FIG. It is a figure which shows an example of the scheduling of the base station shown in FIG. 6 is a flowchart showing an operation example of the base station shown in FIG. 5. It is a figure which shows an example of the battery information transmission method. It is a figure which shows an example of the battery information transmission method. It is a figure which shows an example of radio | wireless resource scheduling.

Hereinafter, embodiments will be described with reference to the drawings. However, the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not clearly shown in the embodiment described below. That is, the present embodiment can be implemented with various modifications (combining the embodiments) without departing from the spirit of the present embodiment.
[1] One Embodiment In recent years, in 3GPP, the possibility of effective communication control by a communication terminal reporting the remaining battery level of a communication terminal to a base station has begun to be deliberated. Although a specific communication control method has not been specified at this stage, it is expected that the specific communication control method will be actively discussed in the future. Therefore, in this embodiment, radio resource allocation (scheduling) based on the remaining battery level of the communication terminal is proposed.

FIG. 1 is a diagram illustrating a configuration example of a wireless communication system according to an embodiment.
The wireless communication system illustrated in FIG. 1 exemplarily includes a base station (for example, e-Node B, eNB) 10 and communication terminals (User Equipment, UE) 20-A, 20-B that can wirelessly communicate with the eNB 10. , 20-C. In the following description, UE 20-A, 20-B, and 20-C are simply referred to as UE 20 when they are not distinguished. Moreover, the number of each of UE20 and eNB10 is not limited to the number illustrated in FIG.

Hereinafter, the communication direction from the eNB 10 to the UE 20 is referred to as downlink. Further, the communication direction from the UE 20 to the eNB 10 is referred to as uplink.
The eNB 10 can perform, for example, data and call relay and communication control between a higher-level device (not shown) and the UE 20, and the UE 20 can transmit and receive data and calls. The data may include user data and control information.

  The UE 20 receives the downlink data from the eNB 10 and reports the reception processing result to the eNB 10. For example, the UE 20 returns an ACK (ACKnowledge) to the eNB 10 if the downlink data can be received without error, and a NACK (Not ACKnowledge) if an error occurs. The eNB 10 transmits new data addressed to the EU 20 when receiving the ACK, and retransmits the errored data when receiving the NACK.

In addition to normal communication, the UE 20 reports information related to the remaining battery capacity of the local station 20 (hereinafter also referred to as battery information) to the eNB 10 at regular or irregular intervals.
FIG. 1 exemplarily shows that the battery (battery) remaining amount of the UE 20-A is less than a predetermined threshold (that is, the remaining battery amount is not sufficient), and the remaining battery amounts of the UE 20-B and 20-C are It shows a state where it is equal to or greater than a predetermined threshold (that is, the remaining battery level is sufficient).

  The eNB 10 that has received the report of the battery information from each UE 20 manages (monitors) the remaining battery capacity of each UE 20. Then, for the UE 20-A whose battery remaining amount is not sufficient, radio resource allocation (scheduling) is performed so that the transmission opportunity (timing) of data addressed to the UE 20-A is smaller than in a normal case. The normal case means a case where the remaining battery capacity is sufficient to be equal to or greater than a predetermined threshold.

  For example, as illustrated in (1) of FIG. 2, when the remaining battery amount of each UE 20-A, 20-B, 20-C is sufficient, the eNB 10 may select each UE 20-A, 20-B, 20-C. Radio resources are allocated so that the downlink data (A, B, C) addressed is distributed in the frequency and time directions. In this example, downlink data A, B, and C are transmitted at different frequencies in the first transmission opportunity, downlink data A and C are transmitted at different frequencies in the second transmission opportunity, and third and fourth transmission opportunities. In this case, downlink data A, B, and C are transmitted at different frequencies. That is, focusing on the downlink data A addressed to the UE 20-A, four transmission opportunities are assigned.

  On the other hand, for example, as shown in (2) of FIG. 2, when the battery remaining amount of the UE 20-B and 20-C is sufficient and the battery remaining amount of the UE 20-A is small, the eNB 10 Radio resources are allocated so that the transmission opportunities of downlink data A addressed to a small number of UEs 20-A are less than in the case of (1) in FIG. In this example, the eNB 10 aggregates and allocates the frequency resources, which are allocated to the downlink data A in four transmission opportunities in (1) of FIG.

  Therefore, in (1) of FIG. 2, the downlink data A addressed to the UE 20-A that is transmitted in a distributed manner at four transmission opportunities is transmitted together at the third transmission opportunity. In this case, the radio resource that was scheduled to be allocated to the downlink data A at a transmission opportunity other than the third transmission opportunity in (1) of FIG. 2 can be allocated to the data B and C other than the downlink data A. It becomes. That is, frequency resources allocated to the data B and C can be increased in transmission opportunities other than the third transmission opportunity. This makes it possible to guarantee the frequency resource that was scheduled to be allocated to the downlink data B and C at the third transmission opportunity at a transmission opportunity other than the third transmission opportunity.

  In the following, as illustrated in (1) of FIG. 2, scheduling when the remaining battery capacity of each UE 20 is sufficient is a normal mode, and the remaining battery capacity is sufficient as illustrated in (2) of FIG. 2. Scheduling when there is a non-UE 20 may be referred to as a priority mode. Further, the scheduling is repeatedly performed every predetermined unit time (cycle). For example, in the case of LTE, the unit time can be a transmission time interval (TTI). In the normal mode, for example, as illustrated in FIG. 4, the eNB 10 is based on the amount of transmission / reception data, the QoS, the communication environment (channel quality) between the eNB 10 and the UE 20, the number of UEs 20 that desire transmission / reception with the eNB 10, and the like. Wireless resources are allocated.

In scheduling in the normal mode, for example, as shown in (1) of FIG. 2, transmission data A, B, and C addressed to each UE 20 are sparsely allocated in the frequency direction and the time axis direction.
On the other hand, in the priority mode, scheduling is performed with an emphasis on the remaining amount of battery (battery) rather than the amount of transmitted / received data, QoS, communication environment, and the like. In the scheduling in the priority mode, for example, as illustrated in (2) of FIG. 2, transmission data A addressed to the UE 20-A whose battery remaining amount is insufficient is allocated so as to be collected (stacked) in the frequency direction.

  Therefore, in the UE 20-A, the reception processing period of the downlink data A can be shortened, and the number of transmissions of the reception processing result (ACK / NACK) can be reduced. For example, as shown in FIG. 3A, when the remaining battery capacity of each UE 20 is sufficient, there are three transmission opportunities for downlink data A addressed to UE 20-A by scheduling in the normal mode. A transmits a response signal (ACK / NACK) to each received data A to the eNB 10.

  On the other hand, for example, as illustrated in FIG. 3B, when the remaining battery level of the UE 20 -A becomes less than a predetermined threshold, the eNB 10 performs the priority mode scheduling so that the downlink to the UE 20 -A is performed. The transmission opportunity of data A is one third transmission opportunity. Thereby, UE20-A needs to transmit the response signal (ACK / NACK) with respect to received data only once with respect to eNB10.

Therefore, it is possible to suppress the battery consumption of the UE 20-A that has insufficient battery remaining capacity.
In the priority mode, for the other first and second transmission opportunities, it is not necessary to allocate a frequency resource to the downlink data A addressed to the UE 20-A. Therefore, the remaining amount of the battery is sufficient for the UE 20-B. And the frequency resource (band) used for transmission of the downlink data B and C addressed to 20-C can be increased.

Therefore, it is possible to prevent a shortage of frequency resources used for transmission of downlink data B and C addressed to other UEs 20-B and 20-C by changing the scheduling for UE 20-A in the priority mode.
This makes it possible to guarantee the frequency resource that was scheduled to be allocated to the downlink data B and C at the third transmission opportunity at a transmission opportunity other than the third transmission opportunity.

[2] Specific Example of Wireless Communication System Hereinafter, details of the above-described wireless communication system will be described.
(2.1) eNB10
FIG. 5 is a block diagram illustrating a configuration example of the eNB 10 according to an embodiment. The eNB 10 illustrated in FIG. 5 exemplarily includes a transmission / reception antenna 11, a radio unit 12, a channel separation unit 13, a channel state measurement unit 14, a report information decoding unit 15, a scheduler 16, and control information. A creation unit 17 and a downlink signal creation unit 18 are provided.

Here, the transmission / reception antenna 11 is a radio interface that receives an uplink radio signal transmitted from the UE 20 and transmits a downlink radio signal addressed to the UE 20. However, antennas may be provided separately for transmission and reception.
The radio unit (RF unit) 12 performs a predetermined radio reception process on a radio signal received from the UE 20 by the transmission / reception antenna 11, and performs a predetermined radio transmission process on downlink data transmitted to the UE 20. The wireless reception processing includes, for example, processing such as low noise amplification of received wireless signals, frequency conversion (down conversion) to baseband frequency, AD (analog / digital) conversion, and the like. For example, the wireless transmission processing includes processing such as DA (digital / analog) conversion of transmission data addressed to the UE 20, frequency conversion (up-conversion) to a radio frequency, and power amplification.

The channel demultiplexing unit 13 demultiplexes report information (control information) from the UE 20, a channel measurement signal, and other channel signals for each channel from the reception signal subjected to predetermined radio reception processing by the radio unit 12.
The report information includes, for example, an ACK / NACK signal, a CQI (Channel Quality Indicator) indicating reception quality at the UE 20, and the like, and in this example, numerical information (battery remaining) indicating the remaining battery power of each UE 20. Amount information or battery information). The report information is channel-separated by the channel separation unit 13 and then sent to the report information decoding unit 15.

The propagation path measurement signal is a known signal called a pilot signal or a reference signal (RS), for example, and is channel-separated by the channel separation unit 13 and then transmitted to the propagation path state measurement unit 14.
Further, the other channel signals include a control channel signal used for transmission of other control information and a data channel signal used for transmission of user data. The channel signal is channel-separated by the channel separation unit 13 and then sent to a reception processing unit (not shown) corresponding to each channel type to be subjected to various baseband reception processes.

  The propagation path state measurement unit (propagation line measurement unit) 14 measures the uplink propagation path state between the eNB 10 and the UE 20 based on the propagation path measurement signal from the channel separation unit 13. Illustratively, the propagation path state measurement unit 14 measures the uplink propagation path state (propagation path quality) by comparing the propagation path measurement signal received from the UE 20 via the uplink propagation path with a replica of the signal. be able to. Note that the eNB 10 can estimate (detect) the uplink channel quality based on the CQI, for example.

The report information decoding unit 15 decodes the report information received from the UE 20. As described above, the report information includes battery information indicating the remaining battery level of each UE 20.
That is, the transmission / reception antenna 11, the radio unit 12, the channel separation unit 13, and the report information decoding unit 15 are used as an example of a reception unit that receives battery information of the UE 20 from a plurality of UEs 20.

In this example, for example, the uplink channel quality obtained by the channel state measurement unit 14 (or the downlink channel quality received from the UE 20) and the battery information obtained by the report information decoding unit 15 are the scheduler 16 is sent out.
The scheduler (control unit) 16 uses the channel quality measured by the channel state measurement unit 14 and the battery information received from the UE 20 as scheduling parameters, and uses radio resources (frequency, time slot) used for downlink data transmission. ) Assignment (scheduling). The scheduling result can be notified to the UE 20. By receiving this notification, the UE 20 can recognize at which frequency and time slot the downlink data destined for the own station 20 is transmitted, and appropriately perform downlink data reception processing at the recognized frequency and time slot. Can be performed. For this notification, for example, a downlink control channel can be used. In this case, the scheduling result is notified to the control information creation unit 17 as one of the downlink control information.

  For example, the scheduler 16 of this example performs control to reduce the transmission opportunity of downlink data addressed to the UE 20 whose battery remaining amount is less than a predetermined threshold. At that time, the scheduler 16 can also increase the frequency resource in the transmission opportunity. Further, with this increase, it is possible to increase the frequency resources allocated to downlink data addressed to other UEs 20 in other transmission opportunities.

  Here, the transmission opportunity of the downlink data addressed to the UE 20 whose battery remaining amount is less than the predetermined threshold may be selected as a transmission opportunity in which the propagation path quality measured by the propagation path state measurement unit 14 is equal to or higher than the predetermined quality. According to this, it is possible to prevent the reception success rate at the UE 20-A from decreasing due to a decrease in the transmission opportunity of the data addressed to the UE 20-A whose battery remaining amount is not sufficient.

For example, even if the transmission frequency to the UE 20-A with insufficient battery remaining is reduced by scheduling in the priority mode, if the data does not reach the UE 20-A correctly, the eNB 10 performs retransmission by receiving a NACK. . As a result, the reception frequency at the UE 20-A is not reduced, and the battery consumption cannot be suppressed.
Therefore, as illustrated in FIG. 7, the scheduler 16 of this example, when performing priority mode scheduling due to the battery consumption of the UE 20 -A, based on the propagation path quality, the transmission opportunity of downlink data addressed to the UE 20 -A. (Timing) can be determined at a timing with better channel quality than other transmission opportunities.

For example, the scheduler 16 tries to assign the transmission timing indicated by the symbol “a” in FIG. 7 to the downlink data addressed to the UE 20-A in a certain scheduling period.
At this time, the scheduler 16 indicates that the downlink channel quality between the eNB 10 and the UE 20-A at the transmission timing (timing “a”) is less than the predetermined quality based on the measurement result in the channel state measuring unit 14. Detect something.

Then, the scheduler 16 does not determine the transmission timing as the transmission timing of the downlink data addressed to the UE 20-A, but waits for the transmission timing at which the channel quality between the eNB 10 and the UE 20-A is equal to or higher than the predetermined quality. .
In the example illustrated in FIG. 7, the scheduler 16 detects from the measurement result in the propagation path state measurement unit 14 that the propagation path quality at the transmission timing indicated by the code “a ′” is equal to or higher than the predetermined quality.

Then, the scheduler 16 performs scheduling so as to transmit data addressed to the UE 20 -A at the transmission timing indicated by the code “a ′”.
In this way, the eNB 10 of this example waits until the transmission timing (the transmission timing indicated by the code “a ′” in FIG. 7) with the best channel quality (communication quality) as much as possible, and transmits the data addressed to the UE 20-A. Can be scheduled. Therefore, the occurrence rate of retransmission can be reduced and the battery consumption of the UE 20-A can be suppressed.

Here, as illustrated in FIG. 8, the propagation path state measurement unit 14 can also measure the transmission path quality (channel state) for each subframe constituting the radio resource, for example.
In the example illustrated in FIG. 8, the scheduler 16 performs scheduling such that one subband (divided band) is allocated to one subframe for UEs 20-B and 20-C whose remaining battery capacity is equal to or greater than the predetermined threshold. Can be performed.

  On the other hand, the channel state of each subframe is measured by the propagation path state measurement unit 14 for the UE 20-A whose remaining battery capacity is less than the predetermined threshold. Then, for example, based on each channel state measurement result, the scheduler 16 can assign two subbands to subframes with better channel states. For example, when the quality of channel state 2 is better than the quality of channel state 1 in FIG. 8, scheduler 16 assigns two subbands to subframe 2 together.

  As described above, the scheduler 16 may perform scheduling such that two subbands are collectively allocated once in two subframes for the UE 20-A whose battery remaining amount is not sufficient. On the other hand, for UEs 20-B and 20-C having a sufficient remaining battery capacity, scheduling may be performed such that one subband is allocated once per subframe.

If the scheduler 16 determines that any channel state is less than the predetermined quality, the scheduler 16 can perform the same communication control in the next period (after two subframes).
As described above, the scheduler 16 performs scheduling in consideration of the propagation path quality, thereby increasing the success probability of communication while minimizing the frequency of data transmission to the UE 20-A having insufficient battery power. Can do.

In addition, when the battery information received from the UE 20-A recovers to the predetermined threshold value or more, the scheduler 16 increases the transmission opportunity of downlink data addressed to the UE 20-A, or increases the frequency resource allocated until then. It may be decreased. The battery information is recovered by charging the battery 26, for example.
Furthermore, the scheduler 16 is an efficient communication method based on, for example, the amount of transmission / reception data, Quality of Service (QoS), channel quality between the eNB 10 and the UE 20, the number of UEs 20 that desire to transmit / receive to the eNB 10, and the like. Can also be selected. Information regarding radio resource allocation and communication method determined by the scheduler 16 is notified to, for example, the downlink signal generator 18.

The control information creation unit 17 creates a scheduling result (information on radio resource allocation) by the scheduler 16.
The downlink signal creation unit 18 assigns (maps) the control information, downlink data addressed to the UE 20, downlink channel measurement signal, and the like to downlink radio resources based on the scheduling result by the scheduler 16.

In this way, the downlink signal created by the downlink signal creation unit 18 is wirelessly transmitted to the UE 20 via the wireless unit 12 and the transmission / reception antenna 11 described above.
As described above, the eNB 10 of this example receives each battery information from the plurality of UEs 20 and controls allocation (scheduling) of radio resources used for transmission of data addressed to the plurality of UEs 20 based on the respective battery information.

Thereby, since eNB10 can perform the scheduling which considered the battery remaining charge of UE20, it becomes possible to suppress the battery consumption of UE20.
(2.2) Operation Example of eNB 10 Next, an operation example (communication control method) of the eNB 10 will be described with reference to FIG.
First, as illustrated in FIG. 9, when data scheduling addressed to each UE 20 is started by the eNB 10, the eNB 10 receives battery information (remaining battery value) from each UE 20 regularly or irregularly.

Then, eNB10 determines whether each battery remaining amount is more than a predetermined threshold value (step S1).
When the eNB 10 determines that the remaining amount of each battery is equal to or greater than the predetermined threshold (Yes route in step S1), the scheduler 16 performs the normal mode scheduling described above (step S2).

On the other hand, when it is determined by the eNB 10 that there is a UE 20 whose battery remaining amount is not equal to or greater than the predetermined threshold (No route in Step S1), the scheduler 16 performs the scheduling in the above-described priority mode.
At this time, the propagation path state measurement unit 14 determines whether or not the transmission path quality (channel state) is equal to or higher than a predetermined quality (step S3).

When it is determined that the channel state is equal to or higher than the predetermined quality (Yes route in step S3), the scheduler 16 determines that the communication status at the transmission timing according to the scheduling is good. Then, the scheduler 16 collectively allocates frequency resources to downlink data addressed to the UE 20-A at this transmission timing (step S5).
On the other hand, when it is determined that the channel state is less than the predetermined quality (No route in step S3), the scheduler 16 determines again whether the channel state is good or bad at the next scheduling cycle.

However, if the channel state continues to be less than the predetermined quality, data addressed to the UE 20-A may not be transmitted indefinitely.
Therefore, in the communication control method of this example, for example, the scheduler 16 determines whether or not the number of times that the channel state is determined to be less than the predetermined quality (hereinafter referred to as the number of determinations) is equal to or greater than the predetermined number. (Step S4).

When it is determined that the number of determinations is equal to or greater than the predetermined number (Yes route in step S4), scheduling is performed so that frequency resources are collectively allocated to data addressed to the UE 20-A regardless of the channel state ( Step S5).
On the other hand, when it is determined that the number of determinations is not equal to or greater than the predetermined number (No route in step S4), the scheduler 16 determines again whether the channel state is good or bad in the next scheduling cycle (step S3).

That is, when the channel state measurement unit 14 measures the channel state to be less than the predetermined quality for a predetermined period (number of times), the scheduler 16 performs scheduling even if the channel state is less than the predetermined quality. Can be tolerated.
Further, in the communication control method of this example, for example, when the remaining battery level of the UE 20-A recovers to the predetermined threshold or more, the scheduler 16 increases the transmission opportunity of downlink data addressed to the UE 20-A. You may schedule. Further, the scheduler 16 may reduce the frequency resource allocated to the downlink data addressed to the UE 20-A.

That is, when the scheduler 16 detects the recovery of the remaining battery level of the UE 20, it can return to the normal mode scheduling from the previous priority mode scheduling.
In addition, when the state where the battery remaining amount of the UE 20-A is less than the predetermined threshold continues, the scheduler 16 can maintain the priority mode scheduling for the UE 20-A.

In such a case, the battery consumption of the UE 20-A whose battery level is insufficient is effectively suppressed, but the battery level is intentionally maintained below the predetermined threshold by the user of the UE 20-A. Sometimes. Then, scheduling of downlink data addressed to other UEs 20-B and 20-C will be affected.
In consideration of such a case, for example, when scheduling in the priority mode continues for a certain period (or a predetermined number of times) for a certain UE 20, the scheduler 16 forcibly returns to scheduling in the normal mode. Also good. For example, a counter can be used for measuring the period (or the number of times).

Further, the period (number of times) may be adaptively changed according to, for example, the amount of communication between the eNB 10 and the UE 20, the number of UEs 20 that are desired to be connected to the eNB 10, and the like. Even in such a communication control method, when the remaining battery level of the UE 20 is recovered, it is possible to return to the scheduling in the normal mode.
According to such a communication control method, it is possible to suppress the influence on other UEs 20 even when the user intentionally maintains the remaining battery level below the predetermined threshold. Become.

In the communication control method of this example, for example, when the battery of the UE 20 has run out (that is, when the remaining battery level of the UE 20 becomes 0%), the UE 20 may be excluded from scheduling.
Thus, in this example, since eNB10 receives each battery information from several UE20 and controls scheduling of the downlink data addressed to each UE20 based on these battery information, it suppresses the battery consumption of UE20. Can do.

(2.3) UE20
FIG. 6 is a block diagram illustrating a configuration example of the UE 20 according to an embodiment. The UE 20 illustrated in FIG. 6 exemplarily includes a transmission / reception antenna 21, a radio unit 22, a channel separation unit 23, a control information decoding unit 24, a battery remaining amount measurement unit 25, a battery 26, and report information. A creation unit 27 and an upstream signal creation unit 28 are provided.

Here, the transmission / reception antenna 21 is a radio interface that receives a downlink radio signal transmitted from the eNB 10 and transmits an uplink radio signal addressed to the eNB 10. This antenna may also be provided separately for transmission and reception.
The radio unit (RF unit) 22 performs a predetermined radio reception process on a radio signal received from the eNB 10 by the transmission / reception antenna 21, and performs a predetermined radio transmission process on uplink data transmitted to the eNB 10. The wireless reception process includes, for example, processes such as low noise amplification of a received wireless signal, frequency conversion (down conversion) to a baseband frequency, and AD conversion. For example, the wireless transmission process includes DA conversion of transmission data addressed to the UE 20, frequency conversion (up-conversion) to radio frequency, power amplification, and the like.

The channel separation unit 23 separates the control information from the eNB 10 and other channel signals for each channel from the reception signal that has been subjected to predetermined wireless reception processing by the wireless unit 22.
The control information includes, for example, an ACK / NACK signal, a CQI indicating reception quality at the eNB 10, a channel measurement signal, and the like, and in this example, includes a scheduling result at the eNB 10. This control information is channel-separated by the channel separation unit 23 and then sent to the control information decoding unit 24.

Further, the propagation path measurement signal is a known signal called a pilot signal or a reference signal (RS), for example, and is subjected to channel separation by the channel separation unit 23, and then performs a propagation state measurement (not shown). ).
Further, the other channel signals include a control channel signal used for transmission of other control information and a data channel signal used for transmission of user data. The channel signal is subjected to channel separation by the channel separation unit 23, and then transmitted to a reception processing unit (not shown) corresponding to each channel type, and subjected to various baseband reception processes.

The control information decoding unit 24 decodes the control information received from the eNB 10. As described above, the control information includes a scheduling result (uplink resource allocation information) in the eNB 10. The uplink resource allocation information is sent to the uplink signal creation unit 28.
As described above, the transmission / reception antenna 21, the radio unit 22, and the channel separation unit 23 are used as an example of a data reception unit that receives data from the eNB 10 using radio resources allocated by the eNB 10 based on the battery information of the UE 20.

The battery 26 supplies power to the UE 20. As the battery 26 of this example, for example, a primary battery (dry battery), a secondary battery (storage battery), a chemical cell such as a fuel cell and a biological cell, a physical cell such as a photocell and a thermal cell, or the like can be used.
The battery remaining amount measuring unit 25 measures the battery remaining amount value of the battery 26. The measured battery remaining value (battery information) is notified to the report information creation unit 27.

The report information creation unit 27 creates report information addressed to the eNB 10 including information such as the battery information, ACK / NACK, and CQI.
That is, the report information creation unit 27, the uplink signal creation unit 28, the radio unit 22, and the transmission / reception antenna 21 are response signal transmission units that transmit ACK / NACK that is an example of a response signal to downlink data received from the eNB 10 to the eNB 10. Used as an example.

Based on the uplink resource allocation information from the control information decoding unit 24, the uplink signal creation unit 28 allocates (maps) the report information, the uplink data, the uplink channel measurement signal, and the like to the uplink radio resource.
In this way, the uplink signal created by the uplink signal creation unit 28 is transmitted to the eNB 10 via the wireless unit 22 and the transmission / reception antenna 21 described above.

That is, the battery remaining amount measurement unit 25, the report information creation unit 27, the uplink signal creation unit 28, the radio unit 22, and the transmission / reception antenna 21 are used as an example of a transmission unit that transmits the battery information of the own station 20 to the eNB 10.
As described above, the UE 20 of this example transmits the battery information of the local station 20 to the eNB 10 and receives data from the eNB 10 using the radio resource allocated by the eNB 10 based on the battery information.

In addition, UE20 of this example may be made to report the said battery information to eNB10 regularly, for example, since eNB10 can confirm the battery remaining charge of each UE20 regularly in this way, Scheduling according to the remaining battery capacity can be implemented adaptively.
However, in this case, the UE 20 that is connected to the eNB 10 but does not plan to communicate with the UE 20 periodically reports the battery information to the eNB 10. As a result, when the reporting cycle is short, the battery consumption of the UE 20 may not be suppressed.

Therefore, the UE 20 may report the battery information included in the control signal addressed to the eNB 10, for example.
According to this, since the timing which reports battery information can be suppressed to the minimum, it becomes possible to suppress the battery consumption of UE20 more effectively. Furthermore, since the battery information is included in the control signal addressed to the eNB 10, it is possible to minimize changes in the device configurations of the eNB 10 and the UE 20.

Further, the UE 20 of this example may report the battery information included in the control signal addressed to the eNB 10 when the remaining battery level of the local station 20 becomes less than a predetermined threshold.
According to this, it becomes possible to further suppress the battery consumption required when the UE 20 reports battery information.
An example of the transmission frame format when battery information is included in the control information is shown in FIG. In FIG. 10, PICH represents a pilot channel, CCH represents a control channel, and DCH represents a data channel.

As illustrated in FIG. 10, the UE 20 of this example, for example, newly adds an item (area) called battery remaining amount information to the control channel of the transmission frame, and transmits battery information (battery remaining amount information) to the control channel. Can be included and sent.
However, as illustrated in FIG. 11, the UE 20 of this example can also add a battery information item to the data channel of the transmission frame and transmit the battery information in the data channel. In this case, the position of the battery information can be known information (for example, 3 bits from the head of the data channel) between the eNB 10 and the UE 20.

As described above, since the UE 20 of this example reports the battery information of the own station 20 to the eNB 10, the eNB 10 can perform radio resource scheduling in consideration of the battery information from the UE 20.
For example, since the eNB 10 performs scheduling in which the transmission timing of data addressed to the UE 20 with a small remaining battery amount is reduced, the UE 20 can reduce the number of times of transmission of the response signal addressed to the eNB 10. As a result, the UE 20 can suppress battery consumption.

[3] Others Note that the configurations and processes of the eNB 10 and the UE 20 described above may be selected as necessary, or may be combined as appropriate.
Moreover, although the case where UE20 transmits a response signal with respect to the downlink data from eNB10 was demonstrated in said example, if UE20 transmits with respect to the data scheduled by eNB10, the same effect as the above is demonstrated. Can be obtained.

  Furthermore, in the above example, the case where the communication control is performed by the eNB 10 and the UE 20 has been described, but the communication control may be performed by other components (entities) of the wireless communication system. For example, each configuration and each process of the eNB 10 and the UE 20 may be distributed and arranged in the radio communication system, or arranged in one device (for example, eNB, UE, radio base station control device, etc.). Also good.

  In the above example, the example in which the UE 20 includes the battery information in the control channel or the data channel and reports to the eNB 10 has been described. However, the battery information may be included in various regions in other transmission frame formats. For example, the battery information may be included in the message part of the preamble part and the message part that form a random access channel (Random Access Channel, RACH) used for starting communication with the eNB 10.

Further, in the above example, the example in which the scheduling is applied to the downlink (downlink) communication has been described. However, the scheduling may be applied to the uplink (uplink) communication.
Regarding the above embodiment, the following additional notes are disclosed.
[4] Appendix (Appendix 1)
A base station capable of communicating with a plurality of communication terminals,
A receiving unit that receives battery information of the communication terminal from the plurality of communication terminals;
A base station comprising: a control unit that controls allocation of radio resources used for transmitting data addressed to the plurality of communication terminals based on the battery information received by the receiving unit.

(Appendix 2)
The radio resource includes a plurality of transmission timings,
The control is
The base station according to claim 1, further comprising a control for reducing the number of transmission timings of the data addressed to a communication terminal whose battery information is less than a predetermined threshold.

(Appendix 3)
The radio resource includes a frequency resource,
The control is
The base station according to supplementary note 2, including a control for increasing a frequency resource used for transmitting the data addressed to a communication terminal whose battery information is less than a predetermined threshold.

(Appendix 4)
Providing a propagation path measurement unit for measuring the propagation path quality with the communication terminal,
The control is
Including a process of selecting a transmission timing at which the propagation path quality measured by the propagation path measurement unit is equal to or higher than a predetermined quality as a transmission timing of the data addressed to a communication terminal whose battery information is less than a predetermined threshold. The base station according to Supplementary Note 2 or Supplementary Note 3, wherein

(Appendix 5)
The control is
Including a process of allowing selection of a transmission timing when the propagation path quality is less than the predetermined quality when the propagation path quality is measured by the propagation path measurement unit to be less than the predetermined quality for a predetermined period. The base station according to appendix 4, characterized by:

(Appendix 6)
The control is
The control according to any one of appendices 2 to 5, further comprising a control for increasing a frequency resource used for transmitting the data addressed to a communication terminal whose battery information is larger than a predetermined threshold according to the decrease. The listed base station.

(Appendix 7)
The control is
The base station according to any one of appendices 2 to 6, further comprising a control for increasing the number of transmission timings of the data addressed to the communication terminal whose battery information has been recovered to the predetermined threshold or more. .

(Appendix 8)
The control is
The base station according to appendix 3, wherein the base station includes control for reducing the frequency resource used for transmission of the data addressed to a communication terminal whose battery information has recovered to the predetermined threshold or more.

(Appendix 9)
A communication terminal capable of communicating with a base station,
A transmitter for transmitting the battery information of the local station to the base station;
A communication terminal comprising: a data receiving unit that receives data from the base station using radio resources allocated by the base station based on the battery information.

(Appendix 10)
The communication terminal according to appendix 9, further comprising: a response signal transmission unit that transmits a response signal for the data received by the data reception unit to the base station.
(Appendix 11)
The transmitter is
The communication terminal according to appendix 9 or appendix 10, characterized in that the information is included in a control channel signal and transmitted.

(Appendix 12)
The transmitter is
The communication terminal according to appendix 9 or appendix 10, wherein the information is transmitted by being included in a data channel signal.
(Appendix 13)
A base station communication control method capable of communicating with a plurality of communication terminals,
Receiving battery information of the communication terminal from the plurality of communication terminals;
A base station communication control method, comprising: allocating radio resources used for transmitting data addressed to the plurality of communication terminals based on the received battery information.

(Appendix 14)
A communication terminal communication control method capable of communicating with a base station,
Send battery information of your station to the base station,
A communication control method for a communication terminal, wherein the base station receives data from the base station using radio resources allocated based on the battery information.

(Appendix 15)
A base station capable of communicating with a plurality of communication terminals;
The communication terminal capable of communicating with the base station;
A receiving unit that receives battery information of the communication terminal from the plurality of communication terminals;
A control unit that controls allocation of radio resources used for transmission of data addressed to the plurality of communication terminals based on the battery information received by the reception unit;
A transmitter that transmits the battery information to the receiver;
A communication system comprising: a data receiving unit that receives the data using the radio resource allocated by the control unit.

10 Base station (eNB)
DESCRIPTION OF SYMBOLS 11 Transmission / reception antenna 12 Radio | wireless part 13 Channel separation part 14 Propagation path state measurement part 15 Report information decoding part 16 Scheduler 17 Control information creation part 18 Downstream signal creation part 20, 20-A, 20-B, 20-C Communication terminal (UE )
DESCRIPTION OF SYMBOLS 21 Transmission / reception antenna 22 Radio | wireless part 23 Channel separation part 24 Control information decoding part 25 Battery residual quantity measurement part 26 Battery 27 Report information creation part 28 Upstream signal creation part

Claims (9)

A base station capable of communicating with a plurality of communication terminals,
A receiver that receives information for controlling battery consumption of the communication terminal from the plurality of communication terminals;
When the information is received by the receiving unit, a control unit that controls setting of radio resources including a plurality of transmission timings and frequency resources of data transmission addressed to the plurality of communication terminals;
With
The control unit controls to reduce the number of transmission timings of data addressed to a communication terminal, which is a value indicating that the information suppresses battery consumption, and to increase frequency resources used for the transmission of the data. To the base station. Providing a propagation path measurement unit for measuring the propagation path quality with the communication terminal,
The controller is
The transmission timing at which the propagation path quality measured by the propagation path measurement unit is equal to or higher than a predetermined quality is selected as the transmission timing of the data destined for the communication terminal, which is a value indicating that the information suppresses battery consumption. Control,
Wherein the base station according to claim 1. The controller is
When the propagation path quality is measured for a predetermined period when the propagation path quality is less than a predetermined quality, control is performed to allow selection of a transmission timing in which the propagation path quality is less than the predetermined quality.
The base station according to claim 2, wherein: The controller is
Control to increase the frequency resource used for transmitting the data addressed to the communication terminal that is not a value indicating that the information suppresses battery consumption according to the decrease,
Characterized in that, the base station according to any one of claims 1-3. A base station capable of communicating with a plurality of communication terminals,
A receiver that receives information for controlling battery consumption of the communication terminal from the plurality of communication terminals;
When receiving the information by the receiving unit, a control unit that controls setting of radio resources including a plurality of transmission timings of data transmission addressed to the plurality of communication terminals;
With
The control unit performs control so as to reduce the number of transmission timings of data addressed to the communication terminal, which is a value indicating that the information suppresses battery consumption, and the information is not a value indicating that the information suppresses battery consumption. A base station that controls to increase frequency resources used for transmission of the addressed data in accordance with the decrease. A communication terminal capable of communicating with a base station,
A transmitter for transmitting information for controlling battery consumption of the communication terminal of the local station to the base station;
The base station receives the information, and is configured to decrease the number of transmission timings of data addressed to the communication terminal, which is a value indicating that the information suppresses battery consumption, and to increase the frequency resource used for transmitting the data. A data receiving unit that receives data from the base station using radio resources including a plurality of transmission timings and frequency resources;
A communication terminal characterized by having A base station communication control method capable of communicating with a plurality of communication terminals,
When receiving information for controlling battery consumption of the communication terminal from the plurality of communication terminals, the information reduces the number of transmission timings of data addressed to the communication terminal, which is a value indicating that battery consumption is suppressed. Controlling the setting of radio resources including a plurality of transmission timings and frequency resources used for transmission of data addressed to the plurality of communication terminals so as to increase frequency resources used for data transmission;
A base station communication method characterized by the above. A communication terminal communication control method capable of communicating with a base station,
Send information for controlling battery consumption of the communication terminal of the local station to the base station,
The base station receives the information, and is configured to reduce the number of transmission timings of data addressed to the communication terminal, which is a value indicating that the information suppresses battery consumption, and to increase the frequency resource used for transmitting the data. Receiving data from the base station using radio resources including a plurality of transmission timings and frequency resources;
A communication method for a communication terminal. A communication system including a plurality of communication terminals and a base station capable of communicating with the plurality of communication terminals,
Each of the plurality of communication terminals is
It has a transmitter that transmits information for controlling battery consumption of its own communication terminal,
The base station
A receiver that receives information for controlling battery consumption of the communication terminal from the plurality of communication terminals;
When receiving the information by the receiving unit, a control unit that controls setting of radio resources including a plurality of transmission timings and frequency resources of data transmission addressed to the plurality of communication terminals,
The control unit performs control to reduce the number of transmission timings of data addressed to a communication terminal, which is a value indicating that the information suppresses battery consumption, and to increase frequency resources used for transmission of the data.
A communication system characterized by the above.

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