JP2015109617A - Control apparatus and control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve power saving effect in a communication terminal by appropriately selecting one of a plurality of radio communication sections for which power saving control is to be performed among the radio communication sections included in the communication terminal.SOLUTION: A mobile communication terminal (1) includes: a determination section (24) that determines one of a plurality of radio communication sections (13, 14) which has the largest amount of communication as a control target, and a power saving control section (23) that controls a driving voltage of an amplifier included in the radio communication section with power saving so that the power consumption of the radio communication section determined as the control target is reduced.

Description

  The present invention relates to a technology for reducing power consumption of a communication device.

  In Patent Document 1 below, when the transmission output level of the high-frequency power amplifier circuit is equal to or higher than the threshold level and the battery voltage exceeds the reference level, the battery voltage is lowered to the reference level and applied to the drain terminal of the semiconductor amplifier. It is described that the transmission power of the high-frequency power amplifier circuit is controlled by supplying the power.

JP 2002-94392 A (published March 29, 2002)

  The present inventors have been studying an effective low power consumption technique in a mobile communication terminal including a plurality of signal amplifying units capable of performing wireless communication in parallel. When the technology described in Patent Document 1 is applied to such a mobile communication terminal, a signal amplifier that can reduce power consumption has the highest maximum output of the communication signal among the above-mentioned multiple signal amplifiers. The signal amplifier amplifies the communication signal. However, according to the inventor's unique knowledge, in a mobile communication terminal as described above, a signal amplifier that amplifies a communication signal having the highest maximum output of the communication signal does not necessarily have the highest power consumption. Therefore, the technique described in Patent Document 1 is not preferable as a technique for reducing the power consumption of the wireless communication performed by the mobile communication terminal as described above, and a technique capable of suitably reducing the power consumption is required.

  The present invention has been made in view of the above problems, and by appropriately selecting a wireless communication unit to be controlled for power saving from a plurality of wireless communication units included in the communication terminal, the communication terminal can save power. The purpose is to increase the power effect.

  In order to solve the above problem, a control device according to one aspect of the present invention is a control device that controls a plurality of wireless communication units included in a communication device and capable of performing wireless communication independently of each other. The determination means for determining the wireless communication unit with the largest communication amount as the control target from among the plurality of wireless communication units, and the power consumption of the wireless communication unit determined as the control target is reduced. And a power saving control means for performing power saving control of a driving voltage of an amplifier provided in the wireless communication unit. A control method according to an aspect of the present invention is a control method for controlling a plurality of wireless communication units included in a communication device and capable of performing wireless communication independently of each other, the plurality of wireless communication units A determination step of determining a wireless communication unit with the largest communication amount as a control target, and an amplifier included in the wireless communication unit so as to reduce power consumption of the wireless communication unit determined as the control target And a power saving control step of controlling the driving voltage of the power saving.

  According to one aspect of the present invention, it is possible to appropriately select a wireless communication unit that is a control target of power saving from among a plurality of wireless communication units included in a communication terminal, and thus increase the power saving effect in the communication terminal. be able to.

It is a block diagram which shows the structure of the mobile communication terminal which concerns on Embodiment 1 of this invention. It is a flowchart which shows the procedure of the power saving control by the mobile communication terminal which concerns on Embodiment 1 of this invention. An example of the power saving control by the voltage control part which concerns on Embodiment 1 of this invention is shown. It is a flowchart which shows the procedure of the power saving control by the mobile communication terminal which concerns on Embodiment 2 of this invention. It is a figure which shows notionally the structure of the data offload which can be used by the mobile communication terminal which concerns on Embodiment 2 of this invention. It is a figure which shows notionally other structures of the data offload which can be used by the mobile communication terminal which concerns on Embodiment 2 of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

Embodiment 1
First, Embodiment 1 of the present invention will be described with reference to FIGS.

  FIG. 1 is a block diagram showing a configuration of a mobile communication terminal 1 according to Embodiment 1 of the present invention. A mobile communication terminal 1 shown in FIG. 1 is a communication device including a plurality of wireless communication units 13 and 14. The plurality of wireless communication units 13 and 14 can perform wireless communication for voice call or data communication with a base station independently of each other. The wireless communication system that can be adopted by the wireless communication units 13 and 14 is not particularly limited. For example, a mobile communication system such as UMTS, CDMA2000 1x, LTE, and LTE-Advanced that is expected to develop in the future may be used. it can.

  As shown in FIG. 1, the mobile communication terminal 1 includes a battery 10, a power management unit 11, a voltage control unit 12, a wireless communication unit 13, a wireless communication unit 14, a switch SW1, a switch SW2, an input / output device 15, a USIM 16, A flash memory 17, a memory 18, a communication processing unit 20, and an application processing unit 30 are provided.

  A voltage Battery_V is supplied to the power management unit 11 from the battery 10 as a power source. The power management unit 11 generates a voltage VBat for the wireless communication units 13 and 14 based on the voltage Battery_V, generates a voltage necessary for each circuit, detects a voltage drop of the battery 10, Or charge control. The voltage control unit 12 generates a voltage Vcnt from the voltage Vbat supplied from the power management unit 11. The voltage Vcnt is a voltage supplied to the wireless communication units 13 and 14 and is a voltage for power saving control of the drive voltage of the amplifier in the wireless communication units 13 and 14. For example, the voltage control unit 12 is configured by a DC-DC converter. The DC-DC converter is also called SMPS (Switch-mode Power Supplies).

  The wireless communication unit 13 includes an antenna ANT1, a duplexer DUP1, an amplifier PA1, a band limiting filter Tx1_BPF, a band limiting filter Rx1_BPF, and a low noise amplifier LNA1. The wireless communication unit 14 includes an antenna ANT2, a duplexer DUP2, an amplifier PA2, a band limiting filter Tx2_BPF, a band limiting filter Rx2_BPF, and a low noise amplifier LNA2.

  In the wireless communication unit 13, the signal Tx1_OUT output from the transmission processing unit 21 is band-limited by the band-limiting filter Tx1_BPF and input to the amplifier PA1 as the signal Tx1_PA_in. The amplifier PA1 has a characteristic according to the voltage Vcc1 applied via the switch SW1, and amplifies the signal Tx1_PA_in and outputs it as a Tx1 signal. The Tx1 signal is radiated as a radio wave from the antenna ANT1 through the duplexer DUP1.

  Further, in the wireless communication unit 13, the radio wave received by the antenna ANT1 is limited in band by the signal band limiting filter Rx1_BPF as the signal Rx1 via the duplexer DUP1, and is input to the low noise amplifier LNA1 as the signal Rx1_LNA. The low noise amplifier LNA1 amplifies the signal Rx1_LNA1 and outputs it as a signal Rx1_IN.

  Note that the duplexer DUP1 is a frequency filter composed of a dielectric, a SAW device, or the like, and distributes the signal TX1 and the signal RX1 having different frequencies. The wireless communication unit 13 and the wireless communication unit 14 can operate independently and in parallel. The details of the operation of the wireless communication unit 14 are the same as those of the wireless communication unit 13, and thus the description thereof is omitted.

  In addition, although this embodiment demonstrates the case of FDD (Frequency Division Duplex) as an example, this invention is not limited to this. In the case of TDD (Time Division Duplex), the duplexers DUP1 and DUP2 can be replaced with a Switch device and a band limiting filter.

  The communication processing unit 20 includes a transmission processing unit 21, a reception processing unit 22, a power saving control unit 23, a determination unit 24, a transmission processing unit 25, a reception processing unit 26, and a communication CPU 27. The transmission processing unit 21 outputs a signal Tx1_OUT to the wireless communication unit 13. The reception processing unit 22 receives the signal Rx1_IN output from the wireless communication unit 13. The power saving control unit 23 performs power saving control on the wireless communication units 13 and 14. The determination unit 24 determines the wireless communication unit that is the target of the power saving control among the wireless communication units 13 and 14. The transmission processing unit 25 outputs a signal Tx2_OUT to the wireless communication unit 14. The reception processing unit 26 receives the signal Rx2_IN output from the wireless communication unit 14. The communication CPU 27 is a processor that executes a function program of the communication processing unit 20. For high-speed signal processing, a DSP may be used in addition to or instead of the communication CPU 27.

  The application processing unit 30 includes an input / output device control unit 31, an authentication unit 32, and an application CPU 33. The input / output device control unit 31 controls the input / output device 15 such as a speaker, a microphone, a display, a key, a sensor, GPS, and IrDA, for example. The authentication unit 32 uses the information of the USIM 16 to perform authentication processing with the network service. The application CPU 33 is a processor that executes a function program of the application processing unit 30. Note that a DSP may be used in addition to or in place of the application CPU 33 for high-speed signal processing.

  Each function program is stored in advance in the flash memory 17, for example. The function program stored in advance in the flash memory 17 may be copied to a memory 18 constituted by DRAM, SRAM, or the like that can be accessed at a higher speed than the flash memory 17.

  As shown in FIG. 1, in the mobile communication terminal 1, the voltage Vbat (first voltage, voltage not subjected to power saving control) supplied from the power management unit 11 to each of the wireless communication units 13 and 14. And a second voltage supply for supplying the amplifier with the voltage Vcnt (second voltage, power-saving controlled voltage) supplied from the voltage controller 12. A path and a switch (switching unit) that selectively switches between the first voltage supply path and the second voltage supply path are provided.

  Specifically, the wireless communication unit 13 is provided with a switch SW1 that switches the voltage Vcc1 supplied to the amplifier PA1 between the voltage VBat and the voltage Vcnt. The wireless communication unit 14 is provided with a switch SW2 that switches the voltage Vcc2 supplied to the amplifier PA2 between the voltage VBat and the voltage Vcnt. The power saving control unit 23 controls the switching of the switches SW1 and SW2, thereby supplying the voltage supplied to the amplifier to each of the wireless communication units 13 and 14 between the voltage Vbat and the voltage Vcnt. It is possible to switch.

  For example, when the connection between the terminals A and B of the switch SW1 is conducted by the control by the control signal SW1_CTRL from the power saving control unit 23, the voltage Vcc1 supplied to the amplifier PA1 becomes the voltage Vcnt. On the contrary, when the terminal A-C of the switch SW1 becomes conductive, the voltage Vcc1 supplied to the amplifier PA1 becomes the voltage Vbat. Similarly, when the terminal DE of the switch SW2 becomes conductive by the control by the control signal SW2_CTRL from the power saving control unit 23, the voltage Vcc2 supplied to the amplifier PA2 becomes the voltage cnt. On the contrary, when the terminal DF of the switch SW2 is conducted, the voltage Vcc2 supplied to the amplifier PA2 becomes the voltage Vbat.

  The voltage value of the voltage Vcnt is appropriately controlled by the voltage control unit 12. For example, the voltage control unit 12 reduces the voltage value of the voltage Vcnt within an allowable distortion characteristic range. As a result, the power consumption of the amplifier PA1 or PA2 driven by the voltage Vcnt is reduced. In general, amplifiers (amplifiers PA1 and PA2) that amplify transmission signals consume much more power than amplifiers (low-noise amplifiers LNA1 and LNA2) that amplify reception signals. Therefore, as in the present embodiment, it is preferable to control the drive voltage of the amplifier that amplifies the transmission signal from the viewpoint of efficiently realizing low power consumption.

  FIG. 2 is a flowchart showing a procedure of power saving control by the mobile communication terminal 1 according to the first embodiment of the present invention. First, the communication amount calculation unit of the determination unit 24 calculates the communication amount A of the wireless communication unit 13 (step S202), and calculates the communication amount B of the wireless communication unit 14 (step S204). Any conventionally known method may be used as a method for calculating the communication amount of each wireless communication unit. For example, the communication amount calculation unit may calculate the communication amount of the wireless communication unit based on the data amount transmitted / received by the wireless communication unit per predetermined unit time.

  Next, the determination unit 24 determines which of the communication amount A and the communication amount B is larger (step S206). In Step S206, when it is determined that “the communication amount A is larger than the communication amount B” (Step S206: YES), the determination unit 24 determines the wireless communication unit 13 as an object of power saving control ( Step S208). Then, the power saving control unit 23 switches the switch SW1 to the voltage Vcnt side (step S210), and controls the drive voltage of the amplifier PA1 included in the wireless communication unit 13 so that the power consumption of the wireless communication unit 13 is reduced. (Step S212).

  On the other hand, when it is determined in step S206 that "the communication amount B is greater than the communication amount A" (step S206: NO), the determination unit 24 determines the wireless communication unit 14 as a target of power saving control. (Step S214). Then, the power saving control unit 23 switches the switch SW2 to the voltage Vcnt side (step S216), and controls the drive voltage of the amplifier PA2 included in the wireless communication unit 14 so that the power consumption of the wireless communication unit 14 is reduced. (Step S218).

  In the above procedure, the switch with the smaller communication amount of the wireless communication units 13 and 14 remains switched to the voltage Vbat side, and thus power saving control is not performed. Further, in the above procedure, when both the wireless communication units 13 and 14 have a small amount of communication that does not require power saving control, neither of the wireless communication units 13 and 14 performs power saving control. Good.

  FIG. 3 shows an example of power saving control by the voltage control unit 12 according to the first embodiment of the present invention. FIG. 3A shows an example of a voltage output from the voltage control unit 12 in the APT method. FIG. 3B is a diagram illustrating an example of a voltage output from the voltage control unit 12 in the ET method. As a typical power saving control method that can be adopted by the voltage control unit 12, for example, an APT (Average Power Tracking) method shown in FIG. 3A and an ET (Envelope Tracking) shown in FIG. A method is mentioned. However, the method of power saving control by the voltage control unit 12 is not particularly limited, and a known power saving control method may be adopted.

  In the APT method, as shown in FIG. 3A, the voltage Vcnt is made to correspond to an average value in a predetermined range unit (for example, frame unit) of the transmission signal in the time axis direction. Since the APT method controls the voltage Vcnt in units of the predetermined range, the amount of power necessary for the operation of the voltage control unit 12 is small. For this reason, the APT method is suitable when the transmission output has a relatively low voltage value corresponding to the middle and low regions. However, in the vicinity of the maximum transmission output, the same as the battery voltage in order to ensure severe distortion characteristics. A high voltage is applied to the amplifier (PA), and power saving cannot be expected when the voltage value near the maximum transmission power is relatively high. On the other hand, the ET method causes the voltage Vcnt to follow the envelope of the transmission signal, as shown in FIG. Since the ET method follows the voltage Vcnt as described above, power saving can be expected even in the vicinity of the maximum transmission output. However, since the amount of power necessary for the operation of the voltage control unit 12 is large, the transmission output with low power consumption is medium. Not suitable for low areas. For this reason, the ET method is suitable when the voltage value in the region near the maximum transmission power is relatively high.

  Thus, since the APT method and the ET method each have advantages and disadvantages, the voltage control unit 12 may vary the power saving method to be applied for each wireless communication unit. Furthermore, the power saving method applied to the wireless communication unit may be switched according to the transmission power region applied to the wireless communication unit subject to power saving control. In addition, the voltage control unit 12 is configured to perform power saving control applied to a wireless communication unit that is a power saving control target based on a predetermined determination condition (for example, temporal distribution of voltage values required by the transmission target data signal). You may make it perform efficient power saving control by changing a method dynamically.

  As described above, according to the mobile communication terminal 1 of the first embodiment, the wireless communication unit with the larger communication volume among the plurality of wireless communication units is determined as a control target, and the wireless communication unit Power saving control was performed. Thereby, the mobile communication terminal 1 of this Embodiment 1 can perform suitable power saving control according to the utilization condition of each radio | wireless communication part, Therefore, the power saving effect in the said mobile communication terminal 1 is improved. be able to. In particular, according to the mobile communication terminal 1 of the first embodiment, the wireless communication unit with the larger communication amount can be determined as the power saving control target at the appropriate time. Even so, an appropriate wireless communication unit can always be the control target. According to the mobile communication terminal 1 of the first embodiment, for example, even when the maximum output power of the wireless communication unit 14 is smaller than the maximum output power of the wireless communication unit 13, the communication amount of the wireless communication unit 14 Is greater than the communication amount of the wireless communication unit 13, power saving control for the wireless communication unit 14 can be performed.

[Embodiment 2]
The mobile communication terminal 1 according to the second embodiment can perform so-called data offload. Data offload is, for example, direct data communication with other mobile communication terminals without using a base station by D2D (Device to Device) communication in order to effectively use radio communication resources in a macro cell. In the HetNet (Heterogeneous Network) configuration, this is a technique for performing handover to small cell communication. In general, if data offload is performed using a frequency band different from the frequency band in which current communication is performed, there is no concern about interference in the same frequency band, and radio resource control is simplified. This embodiment is characterized in that the power saving control is determined based on the execution state of data offload, instead of directly monitoring the communication amount of the wireless communication unit as in the first embodiment. The changes in the configuration of the mobile communication terminal 1 from Embodiment 1 are as follows.

  (Change a) The communication processing unit 20 includes a radio link control unit and a radio resource control unit (both not shown). The wireless link control unit performs processing such as error data control and data retransmission by communicating with EPC, which will be described later. The radio resource control unit controls radio resources in the radio network by communicating with EPC described later.

  (Change b) The determination unit 24 determines a wireless communication unit used for data offload (that is, a wireless communication unit used for data communication after the handover) as a target of power saving control. In response to this, the power saving control unit 23 controls the drive voltage of the amplifier included in the wireless communication unit so that the power consumption of the wireless communication unit used for data offloading is reduced.

  FIG. 4 is a flowchart showing a procedure of power saving control by the mobile communication terminal 1 according to the second embodiment of the present invention. First, the determination unit 24 detects that data offload has been started in the mobile communication terminal 1 (step S402). For example, the determination unit 24 can detect the start of data offload by notification from the radio resource control unit. Next, the determination unit 24 determines which of the wireless communication units 13 and 14 is the wireless communication unit used for the data offload (step S404). If it is determined in step S404 that “the wireless communication unit used for data offload is the wireless communication unit 13” (step S404: YES), the determination unit 24 controls the wireless communication unit 13 to perform power saving control. (Step S406). Then, the power saving control unit 23 switches the switch SW1 to the voltage Vcnt side (step S408), and controls the drive voltage of the amplifier PA1 included in the wireless communication unit 13 so that the power consumption of the wireless communication unit 13 is reduced. (Step S410: power saving control step). On the other hand, when it is determined in step S404 that “the wireless communication unit used for data offloading is the wireless communication unit 14” (step S404: NO), the determination unit 24 saves the wireless communication unit 14. It determines as an object of electric power control (step S412). Then, the power saving control unit 23 switches the switch SW2 to the voltage Vcnt side (step S414), and controls the drive voltage of the amplifier PA2 included in the wireless communication unit 14 so that the power consumption of the wireless communication unit 14 is reduced. (Step S414). In the above procedure, the switch that is not used for data offloading of the wireless communication units 13 and 14 remains switched to the voltage Vbat side, and thus power saving control is not performed.

  FIG. 5 is a diagram conceptually showing a data offload configuration that can be used by the mobile communication terminal 1 according to the second embodiment of the present invention. Here, a case will be described in which communication by the user terminal UE2 is data offloaded to D2D communication using the user terminal UE1 and the user terminal UE2 (corresponding to the mobile communication terminal 1). Data offload to D2D communication is realized by the following steps 1-4.

  (Step 1) The user terminal UE1 and the user terminal UE2 exist in the macro cell. The user terminal UE1 communicates with the macro cell BS (eNB) using the downlink DL1 and the uplink UL1 as radio resources. Similarly, user terminal UE2 communicates with macrocell BS using downlink DL2 and uplink UL2 as radio | wireless resources. D2D communication can be performed between the user terminal UE1 and the user terminal UE2. For example, the communication with the macro cell BS corresponds to L-BAND (for example, 800 MHz band), and the D2D communication corresponds to H-BAND (for example, 3.5 GHz band).

  The macro cell BS is connected to an MME (Mobile Management Entity) / SAE-GW (System Architecture Evolution Gate Way) constituting an EPC (Evolved Packet Core) by an S1 interface. The S1 interface is a communication interface between a base station (eNB) and EPC in LTE. Thereafter, the macro cell BS communicates with the MME / SAE-GW as necessary. The MME is a device in charge of terminal mobility management, authentication, communication path setting, and the like. The SAE-GW is a device that mainly controls the routing of user packets.

  (Step 2) The fact that the user terminal UE1 is capable of D2D communication is notified to the macro cell BS via, for example, the uplink UL1 from the user terminal UE1. Similarly, the fact that the user terminal UE2 is capable of D2D communication is notified to the macro cell BS via the uplink UL2 from the user terminal UE2, for example.

  (Step 3) The macro cell BS secures radio resources (frequency, time, space, etc.) for the D2D communication, and transmits information necessary for the D2D communication to the user terminal UE1 and the user terminal UE2. To do. At this time, the macro cell BS may use a frequency band different from that of normal macro cell communication. In this case, since there is no concern about interference in the same frequency band, radio resource control is simplified.

(Step 4)
The user terminal UE2 performs D2D communication directly with the user terminal UE1 based on the information received from the macro cell BS. At the beginning of communication, either the user terminal UE1 or the user terminal UE2 may transmit a signal such as a beacon using the reserved radio resource. By receiving and exchanging this beacon, the user terminal UE1 and the user terminal UE2 are synchronized, and D2D communication is realized. By controlling the D2D communication by the macro cell BS, the user terminal UE2 does not need to search for a communication partner, and can prevent power consumption increase and interference with other communication in the macro cell.

  The D2D communication increases the amount of communication in the D2D communication, while the amount of communication in the macro cell radio resources (downlink DL1, uplink UL1, downlink DL2, and uplink UL2) decreases. It is possible to reduce the load of radio resources. While the D2D communication is performed in this way, the minimum necessary communication with the macro cell BS may be performed by either the user terminal UE1 or the user terminal UE2. For example, when the user terminal UE1 performs the above-described minimum communication, the radio resources (downlink DL2 and uplink UL2) used by the user terminal UE2 can be kept free. Ultimately, the user terminal UE1 may only receive the downlink DL1. Similarly, the user terminal UE2 may only receive the downlink DL2.

  As the user equipment UE2 in such a data offload configuration, for example, when the mobile communication terminal 1 that communicates with the macro cell BS by the radio communication unit 13 and performs the D2D communication by the radio communication unit 14, Before the D2D communication is started, the communication frequency of the wireless communication unit 13 is “normal”, while the communication frequency of the wireless communication unit 14 is “− (almost does not occur)”. Therefore, the power saving control unit 23 of the mobile communication terminal 1 does not perform power saving control at this point. On the other hand, after the D2D communication is started, the communication frequency of the wireless communication unit 13 becomes “low”, while the communication frequency of the wireless communication unit 14 becomes “high”. Therefore, the power saving control unit 23 of the mobile communication terminal 1 inevitably performs power saving control on the wireless communication unit 14 with the larger communication volume by performing power saving control with the wireless communication unit 14 as a target of power saving control. Therefore, the power saving effect in the mobile communication terminal 1 can be enhanced.

  FIG. 6 is a diagram conceptually illustrating another configuration of data offload that can be used by the mobile communication terminal 1 according to the second embodiment of the present invention. Here, a case where communication by the user terminal UE3 is data offloaded to small cell communication using the user terminal UE1 and the user terminal UE3 (corresponding to the mobile communication terminal 1) will be described. Data offload control for small cell communication is realized by the following steps 1 to 4.

  (Step 1) The user terminal UE1 and the user terminal UE3 exist in the macro cell. The user terminal UE1 communicates with the macro cell BS using the downlink DL1 and the uplink UL1 as radio resources. Similarly, the user terminal UE3 communicates with the macro cell BS using the downlink DL3 and the uplink UL3 as radio resources. The macro cell BS is connected to the MME / SAE-GW constituting the EPC through the S1 interface. Thereafter, the macro cell BS communicates with the MME / SAE-GW as necessary. A small cell is provided in the macro cell. A macro cell and a small cell constitute a HetNet. For example, the macro cell corresponds to L-BAND (for example, 800 MHz band), and the small cell corresponds to H-BAND (for example, 3.5 GHz band). As described above, since a frequency band different from the frequency band used for the macro cell is used for the small cell, there is no fear of interference in the same frequency band, so that radio resource control is simplified.

  (Step 2) When the user terminal UE3 moves into the small cell and becomes the user terminal UE3 ′, the user terminal UE3 ′ uses the macro cell radio resources (uplink UL3 ′, downlink DL3 ′), Communicate with the macrocell BS. In addition, the user terminal UE3 'communicates with the small cell BS using the radio resources (uplink UL4, downlink DL4) of the small cell. The user terminal UE3 'communicates with the small cell BS using a frequency band different from the communication with the macrocell BS. The small cell BS (eNB) is connected to the MME / SAE-GW configuring the EPC by the S1 interface. The small cell BS transmits the mobility information of the user terminal UE3 'to the MME / SAE-GW via the S1 interface. The small cell BS is connected to the macro cell BS through an X2 interface. The X2 interface is a communication interface between base stations (eNBs) in LTE. This may be connected to the EPC via the S1 interface.

  (Step 3) The macro cell BS detects that the user terminal UE3 moves to the position of the UE 3 'and can receive radio waves from the small cell BS, so that the user terminal UE3 is within the small cell area. For example, the macro cell BS is configured such that the user terminal UE3 ′ is a small cell based on the information transmitted from the user terminal UE3 ′ via the uplink UL3 ′ or the information transmitted from the EPC via the S1 interface. It is possible to detect the presence in the vicinity.

  (Step 4) In order to optimize the radio resources in the macro cell, the data communication by the user terminal UE3 ′ starts from the data communication with the macro cell BS using the radio resources of the macro cell (uplink UL 3 ′, downlink DL 3 ′), Handover is performed to data communication with the small cell BS using the radio resources (uplink UL4, downlink DL4) of the small cell.

  As a result, the user terminal UE3 ′ mainly performs data communication with the small cell BS, while communicating with the macro cell BS with minimum necessary communication (for example, communication using the downlink DL3 ′). Only). As a result, the amount of communication in the small cell radio resources (uplink UL4, downlink DL4) increases while the amount of communication in the macrocell radio resources (uplink UL3 ′, downlink DL3 ′) decreases. The load of radio resources of the macro cell can be reduced. Through the data offload, the user terminal UE3 'may perform the minimum necessary communication (for example, only reception of DL3') between the macrocells BS.

  As the user equipment UE3 in such a data offload configuration, for example, the mobile communication terminal 1 that communicates with the macro cell BS by the radio communication unit 13 and communicates with the small cell BS by the radio communication unit 14 is applied. Before the handover to the small cell communication, the communication frequency of the wireless communication unit 13 is “normal”, while the communication frequency of the wireless communication unit 14 is “− (almost does not occur)”. Therefore, the power saving control unit 23 of the mobile communication terminal 1 does not perform power saving control at this point. On the other hand, after the handover to the small cell communication, the communication frequency of the wireless communication unit 13 becomes “low”, while the communication frequency of the wireless communication unit 14 becomes “high”. Therefore, the power saving control unit 23 of the mobile communication terminal 1 inevitably saves the wireless communication unit with the larger communication amount by performing the power saving control with the wireless communication unit 14 as a target of the power saving control. Therefore, the power saving effect in the mobile communication terminal 1 can be enhanced.

  As described above, according to the mobile communication terminal 1 of the second embodiment, of the plurality of wireless communication units, the wireless communication unit performing data offload (that is, after the start of data offload). A wireless communication unit that performs data communication and is a wireless communication unit that actually increases the amount of communication) is determined as a control target, and power saving control of the wireless communication unit is performed. Thereby, the mobile communication terminal 1 of this Embodiment 2 can perform appropriate power saving control according to the utilization condition of each radio | wireless communication part, Therefore, the power saving effect in the said mobile communication terminal 1 is improved. be able to. In particular, according to the mobile communication terminal 1 of the second embodiment, every time the start of data offload is detected, the wireless communication unit in which the start of data offload is detected is determined as a power saving control target. Therefore, even when the usage status of the wireless communication unit is changing, an appropriate wireless communication unit can always be the control target. According to the mobile communication terminal 1 of the second embodiment, for example, even when the maximum output power of the wireless communication unit 14 is smaller than the maximum output power of the wireless communication unit 13, the wireless communication unit 14 performs data off. When loading is started, power saving control for the wireless communication unit 14 can be performed.

  In the above-described embodiments, the case where the mobile communication terminal 1 includes the two wireless communication units 13 and 14 has been described. However, the mobile communication terminal 1 may include three or more wireless communication units. In this case, the mobile communication terminal 1 may perform power saving control with a wireless communication unit having the largest communication amount as a control target from among three or more wireless communication units.

[Summary]
The control device (communication processing unit 20) according to the first aspect of the present invention includes a plurality of wireless communication units (wireless communication units) included in the communication device (mobile communication terminal 1) and capable of performing wireless communication independently of each other. 13, 14), a determination unit (determination unit 24) for determining a wireless communication unit with the largest communication amount as a control target from among the plurality of wireless communication units, and the control target Power saving control means (power saving control unit 23) that performs power saving control of the drive voltage of the amplifier included in the wireless communication unit so that the power consumption of the wireless communication unit determined as is reduced. According to the above configuration, the wireless communication unit having a larger communication volume among the plurality of wireless communication units is determined as a control target, and power saving control of the wireless communication unit is performed. Appropriate power saving control according to the situation can be performed, and therefore the power saving effect in the communication device can be enhanced.

  The control device according to aspect 2 of the present invention further includes a communication amount calculation unit that calculates the communication amount of each of the plurality of wireless communication units in the above aspect 1, and the determination unit includes the plurality of wireless communication units. Based on each communication amount, a wireless communication unit with the largest communication amount may be determined as the control target from among the plurality of wireless communication units. According to the above configuration, the wireless communication unit to be controlled is determined based on the actual communication amount of each wireless communication unit, not based on the specifications (for example, maximum output power, etc.) of each wireless communication unit. In order to perform power saving control of the wireless communication unit, it is possible to perform appropriate power saving control according to the usage status of each wireless communication unit, and thus it is possible to enhance the power saving effect in the mobile communication terminal. .

  In the control device according to aspect 3 of the present invention, in the aspect 1, the determining unit determines a wireless communication unit used for data offloading as the control target from the plurality of wireless communication units. May be. According to the above configuration, the wireless communication unit (wireless communication unit used for data offload) that actually increases the amount of communication, not based on the specifications of each wireless communication unit (for example, maximum output power, etc.) Is determined as a control target, and power saving control of the wireless communication unit is performed, so that appropriate power saving control according to the usage status of each wireless communication unit can be performed, and thus power saving in the mobile communication terminal The effect can be enhanced.

  The control device according to aspect 4 of the present invention is the control apparatus according to aspects 1 to 3, wherein each of the plurality of wireless communication units supplies a first drive voltage that is not controlled by the power saving control unit. A supply path, a second voltage supply path for supplying a second drive voltage controlled by the power saving control means, and a first voltage supply path and a second voltage supply path are selectively switched. The power saving control means includes the switching unit included in the wireless communication unit determined as the control target from the state where the first voltage supply path is selected. You may switch to the state which has selected the 2nd voltage supply path | route. According to the above configuration, a simple control such as simply switching the switching unit (generally a switch is used) affects the voltage supply to a wireless communication unit that is not a power saving control target. Therefore, it is possible to seamlessly switch the voltage supplied to the wireless communication unit targeted for power saving control.

  A control method according to aspect 5 of the present invention is a control method for controlling a plurality of wireless communication units included in a communication apparatus and capable of performing wireless communication independently of each other, and includes a plurality of wireless communication units. A determination step of determining the wireless communication unit with the largest communication amount as a control target, and driving of an amplifier included in the wireless communication unit so that power consumption of the wireless communication unit determined as the control target is reduced And a power saving control step for power saving control of the voltage. According to said structure, there can exist an effect similar to the said control apparatus.

  The control device according to each aspect of the present invention may be realized by a computer, and in this case, a program for causing the computer to realize the control device by causing the computer to operate as each unit included in the control device, and A computer-readable recording medium on which it is recorded also falls within the scope of the present invention.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

  The present invention can be used in various communication devices such as mobile communication terminals.

1 Mobile communication terminal (communication device)
12 voltage control unit 13 wireless communication unit 14 wireless communication unit 20 communication processing unit (control device)
23 Power saving control unit (Power saving control means)
24 Determining unit (determination unit, traffic calculation unit)
PA1, PA2 amplifier SW1, SW2 switch (switching unit)
Vbat voltage (first drive voltage)
Vcnt voltage (second drive voltage)

Claims (5)

A control device for controlling a plurality of wireless communication units included in a communication device and capable of performing wireless communication independently of each other,
A determining unit that determines a wireless communication unit with the largest communication amount as a control target from the plurality of wireless communication units,
A power saving control means for performing power saving control of a driving voltage of an amplifier included in the wireless communication unit so that power consumption of the wireless communication unit determined as the control target is reduced;
A control device comprising: A communication amount calculating means for calculating the communication amount of each of the plurality of wireless communication units;
The determining means includes
The wireless communication unit with the largest communication amount is determined as the control target from the plurality of wireless communication units based on the communication amount of each of the plurality of wireless communication units. The control device described. The determining means includes
The control apparatus according to claim 1, wherein a wireless communication unit used for data offloading is determined as the control target from the plurality of wireless communication units. Each of the plurality of wireless communication units is
A first voltage supply path for supplying a first drive voltage that is not controlled by the power saving control means;
A second voltage supply path for supplying a second drive voltage controlled by the power saving control means;
A switching unit capable of selectively switching between the first voltage supply path and the second voltage supply path;
Have
The power saving control means includes:
The switching unit included in the wireless communication unit determined as the control target is switched from a state where the first voltage supply path is selected to a state where the second voltage supply path is selected. The control device according to any one of claims 1 to 3. A control method for controlling a plurality of wireless communication units provided in a communication device and capable of performing wireless communication independently of each other,
A determination step of determining, as a control target, a wireless communication unit having the largest communication amount from the plurality of wireless communication units,
A power saving control step of performing power saving control of a driving voltage of an amplifier included in the wireless communication unit so that power consumption of the wireless communication unit determined as the control target is reduced;
The control method characterized by including.

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