JP5247365B2 - Base station and radio communication method - Google Patents

Description

  The present invention relates to a base station and a wireless communication method capable of wireless communication with a plurality of wireless communication terminals by the TDMA / TDD system.

  In recent years, wireless communication terminals represented by PHS (Personal Handy phone System) terminals and mobile phones have become widespread, and it has become possible to make calls and obtain information regardless of location or time. Such a wireless communication terminal is connected to a communication network by performing wireless communication with a base station installed at a predetermined location.

  For example, a TDMA (Time Division Multiple Access) / TDD (Time Division Duplex) method is adopted as a representative method of wireless communication using a wireless communication terminal. The TDMA system is a system in which a time slot is subdivided into a plurality of time slots and communication is performed with a plurality of counterparts through the subdivided time slots. The TDD scheme is a scheme in which, for example, a wireless communication terminal and a base station switch data transmission timing alternately and in a short time.

The base station using the TDMA / TDD scheme described above can perform wireless communication in parallel with a plurality of wireless communication terminals through a plurality of TDMA time slots, so that the power of the transmission / reception circuit is always turned on. A large amount of power was consumed. In order to solve such a problem, a technique is known in which the power-on of each time slot is dynamically limited using a special circuit to reduce the power consumption of the unit (for example, Patent Document 1).
JP 2001-119338 A

  By the way, the base station installed on a building pillar or the like may be limited in upper limit power consumption. In addition, when replacing a base station, it is necessary to prevent a newly installed base station from exceeding the upper limit power consumption of an existing base station. However, a newly designed base station is required to have high functionality, multiple lines, and high performance, and it is difficult to maintain the upper limit power consumption. Furthermore, there may occur a situation where the upper limit power consumption allocated to the base station must be reduced due to the installation location.

  Therefore, the base station manufacturer must design a new base station in consideration of such a situation, with low power consumption in mind, but there is a trade-off between high functionality and low power consumption. Therefore, it is impossible to produce a base station that completely corresponds to an unpredictable change in the upper limit power consumption.

  In addition, when the upper limit power consumption of the existing base station is further restricted, it may be possible to reduce the power consumption by adding such a special circuit represented by the prior art, but its manufacture, refurbishment, A great amount of cost is spent for maintenance, and the additional circuit causes an increase in volume and weight.

  In view of such problems, the present invention provides a base station and a wireless communication method capable of easily and dynamically responding to restrictions and changes in the upper limit power consumption depending on the installation location without adding a special circuit. It is intended to provide.

  The base station of the present invention includes a radio communication unit that switches between normal rate communication and low rate communication for a time slot used in communication with a radio communication terminal using a plurality of time slots according to the TDMA / TDD scheme, and the radio communication The power control unit that turns on the power of the transmission system circuit and the reception system circuit of the wireless communication unit according to the period of the time slot to which the communication signal of the terminal is allocated, and the predicted power consumption when a new communication signal is added And when the predicted power consumption predicted by the control unit exceeds an upper limit power consumption, the wireless communication unit increases the predicted power consumption without increasing the number of used time slots. Is configured to allocate the new communication signal to a low-rate time slot so that the power consumption is within the upper limit power consumption.

  With this configuration, when the predicted power consumption exceeds the upper limit power consumption, the wireless communication unit allocates the new communication signal to a low-rate time slot without increasing the time slot in use. Therefore, it easily and dynamically responds to limitations and changes in the upper limit power consumption depending on the location of the base station.

  The base station of the present invention has a configuration in which the control unit predicts the predicted power consumption according to the number of time slots scheduled to be used when the new communication signal is added.

  With this configuration, by predicting the predicted power consumption according to the number of time slots, it is possible to easily limit the upper limit power consumption depending on the location of the base station.

  In the base station of the present invention, when the wireless communication unit adapts the transmission output, the control unit responds to power consumption consumed in a time slot in use when the new communication signal is added. And predicting the predicted power consumption.

  With this configuration, when the transmission output is adapted, the predicted power consumption is predicted according to the accumulated power consumption in the time slot in use, so that the upper limit power consumption depending on the installation location of the base station is adapted to the transmission output. Restrictions can be made.

  In addition, when the new communication signal is added, the base station of the present invention, when the predicted power consumption exceeds the upper limit power consumption, the control unit halves a slot in use at a normal rate. Even if it is assumed to be a rate, when the predicted power consumption exceeds the upper limit power consumption, the power supply control unit is instructed to reduce the transmission output so that the power consumption is lower than the upper limit power consumption, and adaptive modulation is performed. It has the structure which reduces.

  With this configuration, since the transmission output is reduced, the power consumption of the base station can be reduced, and adaptive modulation is performed so that the communication area is not narrowed even if the transmission output is reduced.

  As described above, according to the present invention, it is possible to easily and dynamically cope with the limitation or change of the upper limit power consumption depending on the installation place without adding a special circuit by using the time slot effectively.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiment are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

Hereinafter, a first embodiment of the present invention will be described.
(Wireless communication system 100)
FIG. 1 is an explanatory diagram showing a schematic connection relationship of the wireless communication system 100. The wireless communication system 100 includes a wireless communication terminal 110 (110A, 110B, 110C) as a wireless communication terminal, a base station 120 (120A, 120B), a communication network 130 including a network, a dedicated line, etc., and a relay Server 140. Here, although the wireless communication terminal 110 is cited as a wireless communication terminal, the present invention is not limited to such a case, and is not limited to such a case. Various electronic devices capable of wireless communication such as game devices, DVD players, and remote controllers can also be used as wireless communication terminals.

  In the wireless communication system 100, when a user connects a communication line from his / her own wireless communication terminal 110A to another wireless communication terminal 110C, the wireless communication terminal 110A calls the base station 120A in the communicable area. I do. The calling base station 120A requests the relay server 140 to establish a communication connection with the communication partner via the communication network 130, and the relay server 140 refers to the location registration information and performs wireless communication with the other wireless communication terminal 110C. For example, the base station 120B within the range is selected to secure a communication path between the base station 120A and the base station 120B, and the base station 120B makes an incoming call to the radio communication terminal 110C so that the radio communication terminal 110A and the radio communication terminal 110C communication is established.

Such communication establishment in the wireless communication system 100 is based on the premise that the base station 120 is functioning normally with sufficient power consumption. However, the upper limit power consumption is limited depending on the installation location of the base station 120. The object of the present embodiment is to easily and dynamically respond to the limitation or change of the upper limit power consumption depending on the installation location without performing such additional repair that requires a large amount of cost. Hereinafter, a specific configuration of the base station 120 of the present embodiment that executes such easy and dynamic correspondence will be described in detail.
(Base station 120)
FIG. 2 is a block diagram illustrating a schematic configuration of the base station 120. The base station 120 includes a base station control unit 160, a base station memory 162, a base station wired communication unit 164, and a base station wireless communication unit 166.

  The base station control unit 160 manages and controls the entire base station 120 using a semiconductor integrated circuit including a central processing unit (CPU). The base station control unit 160 uses the program in the base station memory 162 to execute wireless communication with the wireless communication terminal 110, communication connection from the wireless communication terminal 110 to another wireless communication terminal 110, and the like.

  The base station memory 162 is composed of ROM, RAM, EEPROM, nonvolatile RAM, flash memory, HDD, or the like, and stores a program processed by the base station control unit 160. The base station wired communication unit 164 can be connected to various servers including the relay server 140 via the communication network 130. The base station wireless communication unit 166 establishes communication with the wireless communication terminal 110.

  FIG. 3 is a block diagram showing a specific configuration of the base station radio communication unit 166. The base station wireless communication unit 166 includes a communication control unit 180, a transmission system circuit 182, a reception system circuit 184, an RF switch circuit 186, a power supply unit 188 as a power supply path, and a power supply control unit as a data path. 190 and a power switch 192.

  The communication control unit 180 D / A converts the transmission data from the base station control unit 160 and transmits it to the transmission system circuit 182, and A / D converts the reception data from the reception system circuit 184 to make the base station control unit 160. To communicate. Further, the communication control unit 180 instructs the RF switch circuit 186 to switch transmission / reception, or instructs the power supply control unit 190 to turn on / off the power according to the start or end of the time slot.

  The communication control unit 180 also performs normal rate communication for a time slot used in communication with a wireless communication terminal using a plurality of time slots according to the TDMA / TDD scheme, or a half rate that is a lower rate lower than the normal rate. Communication can be performed. The low rate may be a quarter rate.

  FIG. 4 is an explanatory diagram for explaining half-rate communication. Half-rate communication is a technique for assigning communication signals of two wireless communication terminals 110 to one time slot. Accordingly, two communication signals E and F are alternately assigned to one time slot extending over consecutive frames (200A, 200B, 200C, and 200D). In half-rate communication, although it is half of the normal communication rate, the base station 120 can allocate the number of communication signals of the wireless communication terminal 110 exceeding the number of available time slots by effectively using less resources. If the number of available time slots in one frame is four, the base station 120 can assign the number of communication signals of eight wireless communication terminals 110.

  The transmission system circuit 182 includes an IF circuit and an RF circuit related to data transmission, and superimposes transmission data on a carrier wave. The transmission system circuit 182 transmits a carrier wave with designated power.

  The reception system circuit 184 includes an RF circuit and an IF circuit, and extracts received data from the received signal. The RF switch circuit 186 switches the connection with the antenna between the transmission system circuit 182 and the reception system circuit 184 in accordance with TDD.

  The power supply unit 188 supplies power to each circuit of the base station wireless communication unit 166.

  The power controller 190 turns on / off the power switch 192 to control power supply to the transmission system circuit 182 and the reception system circuit 184 described above. Further, the power supply control unit 190 adjusts power (also referred to as transmission output) supplied to the transmission system circuit 182 in accordance with an instruction from the base station control unit 160.

  The base station control unit 160 described above controls the base station wireless communication unit 166 to implement this embodiment.

  The base station control unit 160 allocates a communication signal corresponding to the radio communication terminal 110 to a time slot when there is a communication request for outgoing / incoming calls from the radio communication terminal 110 (when a new communication signal is added). When there is a communication release request from the wireless communication terminal 110, the time slot assignment for the communication signal corresponding to the wireless communication terminal 110 is released. Also, the base station controller 160 counts and stores the number of time slots that are currently in use (assigned) when assigned to a time slot or when the time slot assignment is canceled.

  The base station control unit 160 can switch to normal rate communication or half rate communication by instructing the communication control unit 180 under specific conditions (described later) when there are communication requests from a plurality of wireless communication terminals 110. .

  Furthermore, when the base station controller 160 tries to assign to a time slot from now on or when it tries to release the assignment of a time slot from now on, the number of time slots to be used from now on is determined from the number of time slots in use. And the power consumption of the base station 120 is predicted according to the counted number of time slots to be used. Hereinafter, the predicted power consumption is referred to as predicted power consumption.

  The base station control unit 160 has data (power table stored in advance) in which the number of time slots and the power consumption of the base station 120 correspond to each other, and based on this power table, the base station 120 Predict power consumption.

  FIG. 5 is a diagram illustrating a configuration of the power table. For example, when the number of slots in use is 1 and the number of antennas is 1, the power consumption of the base station 120 is predicted to be A. The procedure for creating the power table will be described later.

  Furthermore, when the predicted power consumption exceeds the upper limit power consumption, the base station control unit 160 switches to a half rate if necessary, and adds a new communication signal to a half rate without increasing the number of used time slots. The communication control unit 180 is instructed to allocate to the rate time slot.

  As a specific example, it is assumed that when three or more time slots are used, the upper limit power consumption is exceeded, that is, only two time slots A and B can be used. In the normal rate state, the base station controller 160 assigns to the time slot A if there is a first communication request, and then assigns it to the time slot B if there is a first communication request. Here, if there is a third communication request, base station control section 160 sets time slot A to half-rate communication, and assigns the first and third communication requests to time slot A. If there is a fourth communication request, the time slot B is set to half rate communication, and the second and fourth communication requests are assigned to the time slot B. In the specific example described above, it is assumed that there is no communication cancellation request.

Hereinafter, a flowchart showing a flow of processing of the base station control unit according to the first embodiment will be described.
(Create power table)
FIG. 6 is a flowchart showing a flow of processing for creating a power table.

  First, the base station controller 160 stops all transmission slots of all antennas, operates all reception slots and measures the power consumption of the base station 120 (S100), and then operates only one reception slot. Then, the power consumption of the base station 120 is measured (S200). From the difference between the power consumption in S100 and the power consumption in S200, the power consumption during reception in each reception slot number is obtained (S300). If the number of reception slots and the power consumption are in a proportional relationship, the base station control unit 160 obtains the power consumption during reception using the proportional relationship, and if there is any other relationship, the base station control unit 160 uses the relationship to determine the power consumption during reception. Obtain power consumption.

  Subsequently, the base station control unit 160 stops all the reception slots of all antennas, operates all the transmission slots with the default transmission output, and measures the power consumption of the base station 120 (S400). The power consumption of the base station 120 is measured by operating only one transmission slot with the transmission output (S500). From the difference between the power consumption in S400 and the power consumption in S500, the transmission power consumption in each transmission slot number is obtained (S600). If the number of transmission slots and the power consumption are in a proportional relationship, the base station control unit 160 obtains the power consumption during transmission using the proportional relationship, and if there is any other relationship, the base station control unit 160 uses the relationship to determine the transmission time. Obtain power consumption.

  The base station control unit 160 creates a power table of the power consumption of the base station 120 for each slot number from the power consumption for reception for each number of reception slots and the power consumption for transmission for each number of transmission slots, and stores it in the memory ( S700). The power table may be created by repeating this flowchart for each number of antennas. If the power consumption of the base station 120 has temperature dependence, this flowchart may be repeated for each temperature, and a power table for each temperature may be stored in the memory. If there is a proportional relationship between each temperature and power consumption, the base station control unit 160 may obtain it by linear interpolation. Note that all of 1 slot, 2 slots, 3 slots, and 4 slots may be measured and reflected in the power table.

Further, the power consumption in the case of half-rate communication may be power consumption between the number of slots and the number of slots added by one. For example, when 2.5 slots are used, the power consumption is between the number of slots 2 and 3, for example, the average value of power consumption B and power consumption C. In the example on the left, the average value is used, but in the case of half-rate communication, it is preferable to employ power consumption according to the power consumption characteristics of the base station 120. Of course, all 0.5 slots, 1.5 slots, 2.5 slots, and 3.5 slots may be measured and reflected in the power table.
(When transmission output is not applied)
FIG. 7 is a flowchart showing the flow of processing when there is a communication request when the transmission output is not adapted. Note that the transmission output of the base station 120 is a default transmission output.

  First, when there is a communication request (in the case of YES in S1), the base station control unit 160 considers the number of slots of communication signal allocation scheduled (normal rate) in addition to the slots currently used, and in FIG. Based on the power table as shown, the power consumption of the base station 120 is predicted (S2). The base station control unit 160 determines whether or not the predicted power consumption exceeds the upper limit power consumption (S3), and if it does not exceed the upper limit power consumption, allocates the requested communication signal to an empty slot (S4). ).

  For example, when there are four slots, the upper limit power consumption is not exceeded until the use of three slots, and when the use of four slots exceeds the upper limit power consumption, the base station control unit 160 determines that 3 in step S4. Up to two slots can be assigned normal rate communication signals.

  When the predicted power consumption exceeds the upper limit power consumption in step S3, the base station control unit 160 determines whether all the slots in use are applied to half-rate communication (S5), and all the half-rates. If it is applied to communication, if there is a vacancy in the slot to which the half rate is applied, a communication signal is assigned thereto, and if there is no vacancy in the half rate slot, the communication request is rejected (S6).

In the case of no in step S5, the base station controller 160 assigns a communication signal to the slot to which the half rate is applied if there is an available slot, and if there is no available slot in the half rate, assigns a normal rate slot. The communication signal is assigned to the half rate (S7). For example, the setting order of half rate communication is made in the order of slot numbers.
(When transmission output is not applied and there is a request to cancel communication)
FIG. 8 is a flowchart showing the flow of processing when there is a communication cancellation request when transmission output is not adapted.

  First, when there is a communication cancellation request (YES in S11), the base station control unit 160 determines whether or not there is a slot to which half-rate communication is applied among slots currently used (S12). ) If there is no slot to which half-rate communication is applied, the communication signal for requesting communication release is released from the slot (S13).

  When there is a slot to which half-rate communication is applied in step S12, the base station control unit 160 considers the number of slots being used and the slot rate by releasing the slot of the communication release request, and FIG. The power consumption of the base station 120 is predicted based on the power table as shown in (S14).

  The base station control unit 160 determines whether or not the predicted power consumption exceeds the upper limit power consumption (S15). If the predicted power consumption exceeds the upper limit power consumption, the base station control unit 160 maintains the half rate and sends the communication signal for the release request from the slot. Release (S16). If the predicted power consumption does not exceed the upper limit power consumption in step S15, the base station control unit 160 cancels the half-rate communication and releases the communication signal for the release request from the slot (S17). For example, the cancellation order of the half rate communication is performed in the order of setting the half rate or in the reverse order.

  As described above, in the first embodiment of the present invention, when the predicted power consumption exceeds the upper limit power consumption, the base station 120 performs new communication without increasing the number of used time slots. Since the signal is allocated to the low-rate time slot, power saving can be achieved so as to flexibly satisfy the specified power consumption that varies depending on the installation conditions. Specifically, base stations installed in buildings are often unable to be changed easily because the power contract with the building owner is fixed, and in the case of replacement of existing base stations, etc. In many cases, it is required that the power consumption of the base station 120 not be exceeded. However, since the new model requires high functionality, multiple lines, and high performance, there is a limit to power saving. By setting the power limit, the base station can autonomously control power consumption.

  Hereinafter, a second embodiment of the present invention will be described. Note that the configuration of the second exemplary embodiment of the present invention is the same as that of the radio communication system 100 and the base station 120 according to the first exemplary embodiment of the present invention, and thus the description of the configuration is omitted.

  The upper limit power consumption is the upper limit power consumption that can be used by the base station 120 and is stored in the base station 120. The upper limit power consumption can be changed by a change request from an operator or the like via the input device of the base station 120 or the communication network 130 during operation.

Hereinafter, a flowchart showing a processing flow of the base station control unit according to the second embodiment will be described. In addition, about the step which concerns on the 2nd Embodiment of this invention, the same code | symbol is attached | subjected to the same thing as the step which concerns on the 1st Embodiment of this invention, and the description is abbreviate | omitted. In the second embodiment, normal rate communication and half rate communication are targeted.
(Create power table)
FIG. 9 is a flowchart showing a flow of processing for creating a power table.

  From the difference between the power consumption of S100 and the power consumption of S200, the power consumption during reception in each reception slot number, in this embodiment, the power consumption during reception at the normal rate and half rate is obtained (S800). Note that the base station control unit 160 may determine the half-rate reception power consumption as half of the full rate or may actually measure the half-rate reception power consumption.

  Subsequently, the base station control unit 160 stops all the reception slots of all antennas, operates all the transmission slots with the default transmission output, and measures the power consumption of the base station 120 (S400). Only one transmission slot is operated with the transmission output, and further, the transmission output is divided into stages, and the power consumption of the base station 120 is measured (S801). Based on the difference between the power consumption in S400 and the power consumption in S801, transmission power consumption at normal rate and half rate is obtained for each stage of transmission output (S802).

  Based on the normal rate reception power consumption and half rate reception power consumption, and the normal rate transmission power consumption and half rate transmission power consumption for each stage of the transmission output, the base station control unit 160, A power table of power consumption of the base station 120 as shown in FIG. 10 is created and stored in the memory (S803). For example, the power table in FIG. 10 is created by combining the power consumption during reception at the normal rate and the power consumption during transmission at the normal rate (for each stage of transmission output). Also, the power table in FIG. 10 is created by combining the power consumption at the time of half-rate reception and the power consumption at the time of half-rate transmission (for each stage of transmission output). The power table for each number of antennas may be created by repeating this flowchart for each number of antennas. The generated power table of FIG. 10 may be further customized so that power consumption is accurate.

FIG. 10 is a diagram illustrating a configuration of the power table. For example, when a normal rate is performed using one slot at transmission output level 1 and a half rate is performed using another slot at transmission output level 2, the power consumption of base station 120 is power consumption A + power consumption. E is expected.
(When adapting transmission output)
11 and 12 are flowcharts showing the flow of processing when there is a communication request in the case of adapting the transmission output. In this flowchart, when the power consumption of the base station 120 is predicted, the power table of FIG. 10 is used.

  First, when there is a communication request (YES in S31), the base station control unit 160 assumes that the communication signal of the communication request is allocated at the normal rate, and consumes the transmission output according to the normal rate and the communication status. The predicted power consumption is calculated by adding the power and the current power consumption of the base station 120 (S32).

  The base station control unit 160 determines whether or not the predicted power consumption exceeds the upper limit power consumption (S33). If the upper limit power consumption is not exceeded, the base station control unit 160 allocates a communication signal to a vacant normal rate slot (S34). . If the normal rate slot is not available in step S34, the base station control unit 160 allocates the communication signal at the half rate. In step S34, the power consumption of the allocated rate is accumulated in the current power consumption of the base station 120.

  When the predicted power consumption exceeds the upper limit power consumption in step S33, the base station control unit 160 assumes that the communication request communication signal is allocated at the half rate, and sets the transmission output according to the half rate and the communication status. A predicted power consumption is obtained by adding the power consumption and the current power consumption of the base station 120 (S35).

  The base station control unit 160 determines whether or not the predicted power consumption exceeds the upper limit power consumption (S36). If the upper limit power consumption is not exceeded, the base station control unit 160 allocates a communication signal to the half-rate slot if it is available. If there is no free space in the half rate slot, the time slot in use is not increased, and the slot in use at the normal rate is set to the half rate (S37). In step S37, the power consumption of the allocated rate is accumulated in the current power consumption of the base station 120.

  If the predicted power consumption exceeds the upper limit power consumption, the base station control unit 160 determines whether or not it is possible to allocate a communication signal to a slot that is currently in use at a normal rate even if it is assumed to be a half rate. If the answer is no in step S38, the slot in use at the normal rate is set to a half rate without increasing the time slot in use (S39). If yes in step S38, the process proceeds to step S21 in FIG. In step S39, the power consumption of the allocated rate is accumulated in the current power consumption of the base station 120. In this flowchart, the power consumption of the base station 120 is obtained by accumulation. However, when the power consumption measuring device is built in, the base station 120 uses the power consumption measuring device. You may make it do.

  In the flowchart shown in FIG. 12, when all slots are half rate communication or all slots are half rate communication, the base station control unit 160 determines whether or not the upper limit power consumption can be suppressed. Try.

  The base station control unit 160 selects a radio communication terminal using the slot having the highest RSSI, obtains a transmission output that the selected terminal requires at a minimum, and based on the obtained base station 120 power consumption is predicted (S21).

  The base station control unit 160 determines whether or not the predicted power consumption exceeds the upper limit power consumption (S22). If the predicted power consumption exceeds the upper limit power consumption, the base station control unit 160 next to the RSSI among the wireless communication terminals using the slot. Select the highest wireless communication terminal, determine the minimum required transmission output of the selected wireless communication terminal, determine the minimum required transmission output accumulated in the order of the selected wireless communication terminal, and base on the basis of the determined The power consumption of the station 120 is predicted (S23). For example, in step S22, the base station control unit 160 uses the sum of the minimum required transmission output accumulated for the selected wireless communication terminal and the sum of the transmission outputs for the unselected wireless communication terminals as the upper limit consumption. Determine whether the power has been exceeded.

  If there is no wireless communication terminal that can be selected after step S23 (Yes in S24), the base station control unit 160 rejects the communication request (S25). When there is a wireless communication terminal that can be selected after step S23 (No in S24), step S22 is repeated.

  If the upper limit power consumption is not exceeded in step S22, the base station control unit 160 decreases to the minimum required transmission output for each selected wireless communication terminal (S26). If the process is via Yes in step S36, the base station control unit 160 assigns all slots to half rate communication and assigns all slots to half rate communication. In order to secure a communication area, adaptive modulation (decrease) is performed on each wireless communication terminal whose transmission output is reduced (S27).

  As described above, in the second embodiment of the present invention, the base station 120 reduces the transmission output when there is a communication request when adapting the transmission output. In addition, adaptive modulation is performed so that the communication area is not narrowed even if the transmission output is reduced.

  In addition, when there is a change request for making the upper limit power consumption lower than the power consumption of the currently consumed base station 120, the base station control unit 160 changes the current power consumption of the base station 120 after the change. When the power consumption of the base station 120 exceeds the upper limit power consumption after the change even if it is assumed that the slot in use at the normal rate is set to a half rate when the upper limit power consumption is exceeded, FIG. You may make it perform the process after step S21.

  As described above, in the embodiment of the present invention, the base station 120 can use the functions and performances of the base station to the maximum even when operating at a specified power consumption or less, which is economical. Are better. This can be realized only by calibration at the time of shipment and software correspondence without increasing the cost and reducing the area. No special hardware changes are required. After installation, it is possible to flexibly respond to future power contract changes. It is possible to reduce the operation cost by lowering the contract power.

  Further, when there is a request for changing the upper limit power consumption, the base station control unit 160 may try step S38 if the current power consumption of the base station 120 is larger than the upper limit power consumption after the change.

  When there is a communication release request, the time slot assignment to the communication signal corresponding to the wireless communication terminal 110 is released based on the processing of the flowchart of FIG. Note that when the power consumption of the base station 120 is predicted, the power table of FIG. 10 is used.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  Note that each step in the wireless communication method of the present specification does not necessarily have to be processed in time series in the order described in the flowchart, and may include processing in parallel or a subroutine.

  The present invention relates to a base station and a wireless communication method capable of wireless communication with a plurality of wireless communication terminals using the TDMA / TDD scheme.

It is explanatory drawing which showed the rough connection relation of the radio | wireless communications system. It is the block diagram which showed the schematic structure of the base station. It is the block diagram which showed the specific structure of the base station radio | wireless communication part. It is explanatory drawing for demonstrating half rate communication. It is a figure which shows the structure of the electric power table which concerns on the 1st Embodiment of this invention. It is the flowchart which showed the flow of the process of preparation of an electric power table. It is the flowchart which showed the flow of the process when there is a communication request | requirement in case transmission output is not adapted. It is the flowchart which showed the flow of the process when there exists a communication cancellation | release request | requirement in case transmission output is not adapted. It is the flowchart which showed the flow of the process of preparation of an electric power table. It is a figure which shows the structure of the electric power table which concerns on the 2nd Embodiment of this invention. It is the flowchart which showed the flow of the process when there exists a communication request | requirement in the case of adapting a transmission output. It is the flowchart which showed the flow of the process when there exists a communication request | requirement in the case of adapting a transmission output.

Explanation of symbols

DESCRIPTION OF SYMBOLS 110 Wireless communication terminal 120 Base station 162 Base station memory 164 Base station wired communication part 166 Base station wireless communication part (wireless communication part)
160 Base station control unit (control unit)
182 Transmission system circuit 184 Reception system circuit 190 Power supply control unit

Claims (4)

A wireless communication unit that switches between normal rate communication and low rate communication for a time slot used in communication with a wireless communication terminal using a plurality of time slots according to the TDMA / TDD scheme;
A power supply control unit for turning on the transmission system circuit and the reception system circuit of the wireless communication unit according to the time slot period to which the communication signal of the wireless communication terminal is allocated;
If the wireless communication unit to adapt the transmission power, and a control unit for predicting a predicted power consumption according to the power consumed in the time slots in use when a new communication signal is added,
When the predicted power consumption predicted by the control unit exceeds the upper limit power consumption, the wireless communication unit does not increase the used time slot so that the predicted power consumption falls within the upper limit power consumption. Assign the new communication signal to a low rate time slot ,
When the new communication signal is added, the control unit may assume that the slot in use at the normal rate is set to a half rate when the predicted power consumption exceeds the upper limit power consumption. when the power consumption to be expected exceeds the upper limit power consumption, the base, characterized in Rukoto lower the adaptive modulation instructs the decrease of the transmission output to be less than the upper limit power to the power controller Bureau. A wireless communication unit that switches between normal rate communication and low rate communication for a time slot used in communication with a wireless communication terminal using a plurality of time slots according to the TDMA / TDD scheme;
A power supply control unit for turning on the transmission system circuit and the reception system circuit of the wireless communication unit according to the time slot period to which the communication signal of the wireless communication terminal is allocated;
When the wireless communication unit adapts the transmission output, a control unit that predicts the predicted power consumption according to the power consumption consumed in the time slot being used when a new communication signal is added, and
When the predicted power consumption predicted by the control unit exceeds the upper limit power consumption, the wireless communication unit does not increase the used time slot so that the predicted power consumption falls within the upper limit power consumption. Assign the new communication signal to a low rate time slot,
When there is a change request for making the upper limit power consumption lower than the current upper limit power consumption, the control unit assumes the current consumption even if it assumes that the slot in use of the normal rate is set to the half rate. When the power exceeds the upper limit power consumption after the change, the base station is configured to instruct the power supply control unit to decrease the transmission output so as to be equal to or lower than the upper limit power consumption after the change and to reduce adaptive modulation. In a radio communication method of a base station provided with a radio communication unit, which switches between normal rate communication and low rate communication for a time slot used in communication with a radio communication terminal using a plurality of time slots according to the TDMA / TDD system.
A power control step of turning on the power of the transmission system circuit and the reception system circuit of the wireless communication unit according to the period of the time slot to which the communication signal of the wireless communication terminal is allocated;
When the wireless communication unit adapts the transmission output, a prediction step of predicting the predicted power consumption according to the power consumption consumed in the time slot in use when a new communication signal is added;
When the predicted power consumption predicted in the prediction step exceeds the upper limit power consumption, the new communication signal is set so that the predicted power consumption falls within the upper limit power consumption without increasing the time slot in use. Assigning to a low rate timeslot ;
When the new communication signal is added, when the predicted power consumption exceeds the upper limit power consumption, even if it is assumed that the slot in use at the normal rate is set to a half rate, the predicted consumption When the power exceeds the upper limit power consumption, reducing the transmission output and reducing adaptive modulation so as to be less than or equal to the upper limit power consumption; and
A wireless communication method comprising: In a radio communication method of a base station provided with a radio communication unit, which switches between normal rate communication and low rate communication for a time slot used in communication with a radio communication terminal using a plurality of time slots according to the TDMA / TDD system.
A power control step of turning on the power of the transmission system circuit and the reception system circuit of the wireless communication unit according to the period of the time slot to which the communication signal of the wireless communication terminal is allocated;
When the wireless communication unit adapts the transmission output, a prediction step of predicting the predicted power consumption according to the power consumption consumed in the time slot in use when a new communication signal is added;
When the predicted power consumption predicted in the prediction step exceeds the upper limit power consumption, the new communication signal is set so that the predicted power consumption falls within the upper limit power consumption without increasing the time slot in use. Assigning to a low rate timeslot;
If there is a change request to make the upper limit power consumption lower than the current upper limit power consumption, the current power consumption will be When the upper limit power consumption is exceeded, the step of reducing the transmission output and lowering the adaptive modulation so as to be lower than the upper limit power consumption after the change;
A wireless communication method comprising: