JP3381783B2 - Transmission power control method for cellular system, base station apparatus, control station, and mobile station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable continuous communication by preventing communication interruption from being continued between a base station and a mobile station by updating transmission power at the base station so as to be close to prescribed reference power after the transmission power is increased or decreased. SOLUTION: When communication is started, the base station sets down transmission power P for the signal of a down line to an initial value P0. When the reception of a slot is made successful and a down control instruction in that slot instructs power increase, a transmission power control part decreases the transmission power of the down line just by ΔP. When the reception of the slot is failed, on the other hand, the transmission power control part 205 updates transmission power Pa into r(Pb-C)+C so that a value r(Pb-C), where a coefficient (r) is multiplied to a difference (Pb-C) between transmission power Pb before updating and predetermined reference power C, can be equal with a difference (Pa-C) between transmission power Pa after updating and predetermined reference power C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cellular system in which a mobile station communicates via one or a plurality of base stations installed in a service area, and more particularly to a control command for transmission power transmitted by the mobile station. The present invention relates to a transmission power control method and a base station apparatus for a cellular system in which a base station controls transmission power according to the above.

[0002]

2. Description of the Related Art In a code division multiplexing cellular system, since many lines use the same frequency, the received power (desired wave power) of a signal on one line interferes with another line. It becomes the interference wave power. Therefore, in the uplink transmitted by the mobile station and received by the base station, when the desired wave power exceeds a predetermined value, the interference wave power increases and the line capacity decreases. In order to prevent this, it is necessary to strictly control the transmission power of the mobile station. In the uplink transmission power control, the base station measures the desired wave power, compares it with the control target value, and when the desired wave power is large, the uplink transmission power to the mobile station (hereinafter " (Also referred to as "uplink transmission power") is transmitted, and if the desired wave power is small, an uplink control command to increase the uplink transmission power is transmitted to the mobile station. Then, the mobile station increases or decreases the uplink transmission power according to the uplink control command. Regarding the transmission power control method for this uplink, US Pat.
056,109 (Gilhousen et al., "Method
and apparatus for controlling transmission power in a CDMA cellular mobile telephone system. "). The transmission of the uplink control command in this transmission power control uses the downlink which is transmitted from the base station to the mobile station.

On the other hand, also in the downlink, high line capacity is realized by controlling the transmission power so that the ratio of the desired wave power to the interference wave power becomes a predetermined amount. More specifically, in the downlink transmission power control, the mobile station measures the downlink reception quality and compares it with the control target value,
When the reception quality is higher than the control target value, a downlink control command for decreasing the downlink transmission power (hereinafter also referred to as “downlink transmission power”) is transmitted to the base station, and the reception quality is lower than the control target value. If it is lower, a downlink control command for increasing downlink transmission power is transmitted to the base station. Then, the base station increases or decreases the downlink transmission power according to the downlink control command.

However, according to this method, the base station cannot receive the downlink control command from the mobile station when the propagation loss from the mobile station to the base station rapidly increases as the location of the mobile station moves. At the same time, the mobile station may not be able to receive the uplink control command from the base station. At this time, in the conventional method in which the base station controls the downlink transmission power only by the downlink control command from the mobile station, if the state in which the propagation loss continues to increase continues, the base station causes the downlink control command from the mobile station. Since the base station does not increase the downlink transmission power while it is unable to receive, the mobile station is unable to receive the uplink control command from the base station, and the uplink transmission power of the uplink signal can be increased. However, there is a problem that the communication between the base station and the mobile station continues to be interrupted.

In general, in a signal received by a base station, a portion of user information such as voice and data can be accurately decoded by performing error correction or the like even if a reception error occurs momentarily. A relatively long amount of information is collectively coded, and a relatively long time is also required for decoding to collectively decode a long amount of information.

However, when the mobile station moves at a high speed, when performing high-speed transmission power control that keeps the reception quality constant by following the high-speed fading fluctuation of the propagation path, even if the user information is accurate. Even if it can be decoded to, since it is necessary to determine the control command instantaneously, the determination of the control command cannot obtain an effect such as error correction,
There are relatively many mistakes.

Since such a determination error of the control command occurs in relation to the increase / decrease of the propagation loss, it is relatively likely to occur continuously. When the control command judgment error continues, the base station cannot control the downlink transmission power of the downlink signal according to the downlink control command from the mobile station, and the mobile station cannot accurately receive the downlink signal. There is a possibility that On the other hand, in this state, the mobile station cannot receive the uplink control command from the base station included in the downlink signal, so that the uplink transmission power of the uplink signal may not be controlled. At this time, in the base station, not only the downlink control command determination error frequently occurs in the uplink signal, but also the user information may not be correctly received. Even in this case,
There arises a problem that the communication between the base station and the mobile station continues to be interrupted.

Further, in a cellular system, there is a technique called soft handover in which, when a mobile station moves between cells, the lines are switched between cells while setting lines simultaneously with a plurality of base stations near the boundary. This technique is an important technique especially in a cellular system that employs a code division multiplex system. Regarding the soft handover, US Pat. No. 5,102,501 (Gi
lhousen et al., "Method and system for providing a
soft handoff in communications in a CDMA cellular
telephone system. ").

When controlling the transmission power of the uplink during the execution of such soft handover, a plurality of base stations measure the desired wave power of the mobile station, and each base station independently adjusts the transmission power of the uplink. Send an uplink control command to the mobile station.
Then, when the mobile station receives each uplink control command and receives a different uplink control command, the mobile station preferentially follows the command to reduce the uplink transmission power. For this method, see the literature (TIA /
EIA Interim Standard, Mobile Station-Base Station
Compatibility Standard for Dual-Mode Wideband Spre
ad Spectrum Cellular System, TIA / EIA / IS-95-A, Tele
communicationIndustry Association, May 1995, 6.6.
6.2.7.2 Reverse Traffic Channel Power Control Duri
ng Soft Handoff). Thus, when the uplink control command is different between the base stations, by preferentially following the command to reduce the uplink transmission power, it is possible to prevent the desired wave power from exceeding the control target value in any base station, A high line capacity is realized on the uplink.
Therefore, in this method, it is important that the mobile station can receive the uplink control command from all the base stations that may minimize the propagation loss in the uplink.

It is important to control the transmission power of the downlink during the execution of the soft handover so that the base station can receive the downlink control commands of all mobile stations which may minimize the propagation loss of the uplink. is there.

Therefore, a method is conceivable in which the transmission power of the downlink is controlled so that the desired wave power from each base station becomes equal in the mobile station. However, according to this method, the base station, which has a large propagation loss to the mobile station, sets the downlink transmission power to that much, so that the interference wave power increases and the downlink capacity decreases. As a method of suppressing the decrease in the capacity of the downlink, there is a method of controlling the downlink transmission power of each base station to be equal to each other. This method is described in the literature (Andersson, "Tuning two macro diversityperforma
nce in a DS-CDMA system. "Proc. IEEE 44th Vehicula
r Technology Conference, pp.41-45, June 1994).

In this method, the received power of the uplink control command from the base station having a small propagation loss to the mobile station is larger than the received power of the uplink control command from the base station having a large propagation loss, and the difference between them is large. At times, the probability of failure to receive an uplink control command from a base station with large propagation loss increases. In such a case, the uplink transmission power is mainly controlled by the uplink control command from the base station having a small propagation loss, so that there is not much problem. On the other hand, when the difference in propagation loss is small, it is important to control the uplink transmission power according to both base stations. In such a case, since the respective uplink control commands can be received with substantially the same power, the probability that both uplink control commands can be accurately received becomes high. Therefore, it is possible to receive all the uplink control commands from the base station that may minimize the uplink propagation loss due to the uplink transmission power control.

Also, during execution of soft handover, when the magnitude of the propagation loss from the mobile station to each base station is switched at high speed due to fading fluctuations, etc., the base station transmitting to the mobile station is Accordingly, the base station having the minimum propagation loss is transmitting at any moment without switching at high speed.
At this time, if the downlink transmission power of the base station is not equal to each other, when the base station that minimizes the propagation loss is switched,
Since the reception quality increases or decreases, the reception quality is likely to deteriorate. However, if the downlink transmission powers of the respective base stations are equal to each other, even if the base station with the smallest propagation loss is switched, the reception quality is kept substantially constant, and the reception quality is further improved. You can also

In such downlink transmission power control,
The mobile station measures the downlink reception quality, compares it with the control target value, and if the reception quality is higher than the control target value, sends a downlink control command to reduce the downlink transmission power to the base station. If the reception quality is lower than the control target value, the downlink control command for increasing the downlink transmission power is transmitted to the base station. During execution of the soft handover, the plurality of base stations receive the downlink control command transmitted by the mobile station. Then, each base station controls the downlink transmission power while similarly increasing or decreasing it according to the downlink control command. Therefore, if the initial values of the downlink transmission powers of the respective base stations are equal to each other, the increase or decrease is repeated in the same manner, so if there is no error in receiving the downlink control command,
The downlink transmission power is controlled while maintaining the same state.

However, according to this method, the base station with the smallest propagation loss to the mobile station can receive the downlink control command from the mobile station almost accurately, but the base station with the large propagation loss from the mobile station can receive the downlink control command. Since the received power of the control command is small, it often fails to receive the downlink control command from the mobile station. Therefore, it becomes impossible to keep the downlink transmission power of each base station equal to each other.

At this time, the downlink transmission power of the base station having a large propagation loss from the mobile station becomes smaller than the downlink transmission power of the base station having the smallest propagation loss from the mobile station due to the failure to receive the downlink control command. In this case, a reception error is likely to occur in the uplink control command for controlling the transmission power of the uplink transmitted by the base station having a large propagation loss from the mobile station. As mentioned above, in uplink transmission power control,
Since it is important for the mobile station to be able to receive the uplink control command from all base stations that may minimize the uplink propagation loss, such a reception error of the uplink control command causes the uplink channel capacity to increase. There is a problem of decreasing. In addition, there is a problem that the diversity effect due to the above-mentioned plurality of base stations transmitting with the same power is reduced, and the reception quality is easily deteriorated.

On the other hand, the downlink transmission power of the base station having the large propagation loss from the mobile station becomes higher than the downlink transmission power of the base station having the smallest propagation loss from the mobile station due to the failure to receive the uplink control command. In this case, as in the case of the method described above, in which the downlink transmission power of the downlink is controlled so that the desired wave power from each base station becomes equal in the mobile station, the propagation loss to the mobile station is reduced. Since a large base station sets the downlink transmission power to a large value, the interference wave power increases and the downlink capacity decreases.

In a base station having a large propagation loss from a mobile station, as a countermeasure against a failure to receive a downlink control command from the mobile station due to a large propagation loss, Japanese Patent Laid-Open No. 9-31260
As described in Japanese Patent Publication No. 9, there is a method in which, in each base station, a downlink control command having low reception quality and low reliability is ignored and downlink transmission power is independently controlled. However, that method does not allow each base station to transmit with the same power, and the above-mentioned problem cannot be solved. Further, in Japanese Unexamined Patent Publication No. 9-312609, control signals transmitted from mobile stations are collected at a combining station (control station) via a base station, and the downlink transmission power of each base station is controlled by the information. Methods are also described. However, when attempting to realize high-speed transmission power control by this method, there is a problem that the amount of control signals transmitted between control stations connected to each base station and the base station increases. In addition, if an attempt is made to reduce the amount of control signal transmission, there is a problem that the delay becomes large and high-speed transmission power control cannot be realized.

[0019]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to solve the above-mentioned problems when the propagation loss between the base station and the mobile station suddenly increases, Even if there is a continuous error in the determination of the downlink control command of, the transmission power control of the cellular system that can continue the communication without the communication between the base station and the mobile station being continuously interrupted To provide a method.

Another object of the present invention is to solve the problems as described above, and to execute a soft handover during the execution of a soft handover without significantly increasing the transmission amount of control signals between the base station and the control station. In each base station, even if an error occurs in the reception of the downlink control command from the mobile station for downlink transmission power control, each base station should be able to transmit at approximately the same power, and An object of the present invention is to provide a transmission power control method for a cellular system that can obtain high capacity in the downlink.

[0021]

According to the present invention, the number of mobile stations is one.
While setting up a line with one or more base stations,
Each time the base station receives a control command from the mobile station, the base station increases or decreases transmission power according to the control command, and the transmission power of the base station after the increase or decrease approaches a predetermined reference power. The transmission power control operation for updating the transmission power is repeated.

Therefore, while the mobile station sets up a line with one or more base stations, the base station follows the control command each time it receives a control command from the mobile station. The difference (Pa−C) between the transmission power P of the base station after increasing or decreasing the transmission power P and the increase or decrease of the transmission power P and the predetermined reference power C is the transmission power Pb before the update and the predetermined reference power C. The transmission power P is updated by {Pa = r (Pb−C) + C} such that the difference (Pb−C) from r is r times (0 ≦ r <).

The value of r is transmitted when the product of (1-r) and the difference between the maximum value and the minimum value of the control range of the transmission power P increases or decreases the transmission power according to the control command. It is set to be smaller than the change in power.

Specifically, it is provided with a plurality of cells, a plurality of base stations respectively installed in the plurality of cells, and a mobile station moving in each cell, and the mobile station is one or a plurality of base stations. In a transmission power control method of a cellular system for performing communication by setting a line between a mobile station and a base station while setting a line with one or a plurality of base stations, Repeating a first transmission power control operation of transmitting a control command of transmission power of the base station to the base station, receiving the control command by the base station, and changing the transmission power according to the received control command. Together with the second transmission power control operation of updating the transmission power by the base station so that the absolute value of the difference between the decibel value of the predetermined reference power and the decibel value of the transmission power becomes small at a predetermined ratio. Characterized by repeating .

The transmission power control method for a cellular system according to the present invention is characterized in that the reference power is the maximum transmission power of the transmission powers.

Further, according to the present invention, while the mobile station sets up a line with a plurality of base stations, the base station follows a control command every time it receives a control command from the mobile station. Increase or decrease the transmission power, reduce the difference between the transmission powers of the base stations after the increase or decrease, and the transmission power so that the transmission power approaches the reference power commonly set among the base stations. The transmission power control operation for updating is repeated.

To this end, each of the plurality of base stations, while the mobile station is establishing a line with the plurality of base stations,
Each time a control command is received from the mobile station, the transmission power P is increased or decreased according to the control command, and the transmission power Pa of the base station after the increase or decrease and the transmission power P are commonly set among a plurality of base stations. The difference (Pa-C) from the reference power C is r of the difference (Pb-C) between the transmission power Pb before update and the reference power C.
{Pa = r (Pb-C) + so that it becomes double (0≤r <1)
C}, and the transmission power P is updated.

Further, in the transmission power control method of the cellular system according to the present invention, the product of the difference between the maximum value and the minimum value of the control range of the transmission power P and (1-r) is the transmission power according to the control command. It is characterized in that r is set so as to be smaller than the change in the transmission power when increasing or decreasing.

[0029] Specifically, it is provided with a plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, and the mobile station is one or a plurality of base stations. In a transmission power control method for a cellular system that establishes a line with a base station and communicates with the mobile station, while the mobile station sets up a line with a plurality of base stations, the mobile station uses the plurality of base stations. A first transmission power for transmitting a control command of transmission power of a base station to each of the plurality of base stations, and changing the transmission power according to the control command received by each of the plurality of base stations. While repeating the control operation, the absolute value of the difference between the decibel value of the reference power and the decibel value of the transmission power commonly set among the plurality of base stations is small at a rate common to the plurality of base stations. So that each of the plurality of base stations There and repeating the second transmission power control operation for updating the transmission power.

Further, the transmission power control method of the cellular system according to the present invention is characterized in that the reference power is the maximum transmission power of the transmission power.

Further, the transmission power control method of the cellular system according to the present invention is characterized in that the reference power is an intermediate power between the decibel value of the maximum transmission power of the transmission power and the decibel value of the minimum transmission power.

The transmission power control method for a cellular system according to the present invention is characterized in that the reference power is the minimum transmission power of the transmission power.

Further, in the transmission power control method for a cellular system according to the present invention, each of the plurality of base stations calculates a statistical value of transmission power and notifies the control station of the plurality of base stations. Using the statistic value of, calculate a reference value representing the reference power and notify the plurality of base stations, the plurality of base stations, the reference power represented by the notified reference value It is characterized by using.

The transmission power control method for a cellular system according to the present invention is characterized in that the maximum statistical value of the statistical values is used as the reference value.

Further, the transmission power control method for a cellular system according to the present invention is characterized in that the control station determines the common ratio according to a mutual difference of the statistical values of the plurality of base stations. .

Further, in the transmission power control method of the cellular system according to the present invention, the control station updates the transmission power by the common ratio according to the mutual difference of the statistical values of the plurality of base stations. It is characterized by determining.

Further, in the transmission power control method of the cellular system according to the present invention, the mobile station has information on the cumulative control value of the transmission power in the base station, and the cumulative control value is instructed to control the transmission power of the base station. Each time it is transmitted, it is transmitted to the plurality of base stations at a time interval longer than the repetition time interval of the update operation of the transmission power, and the plurality of base stations use the received cumulative control value. The reference power is determined and used.

Further, the transmission power control method of the cellular system according to the present invention is characterized in that the transmission power is updated by the plurality of base stations at the same time.

The base station device of the cellular system of the present invention is
While the mobile station is establishing a line with one or more base stations, each time it receives a control command from the mobile station,
It is characterized by comprising means for increasing or decreasing the transmission power according to the control command, and means for updating the transmission power so that the transmission power of the base station after the increase or decrease approaches a predetermined reference power.

To this end, while the mobile station sets up a line with one or more base stations, the base station follows the control command each time it receives a control command from the mobile station. The difference (Pa−C) between the transmission power Pa of the base station after increasing or decreasing the transmission power P and the increase or decrease of the transmission power P and the predetermined reference power C is the transmission power Pb before the update and the predetermined reference power. R times the difference from C (Pb−C) (0 ≦ r <
The transmission power P is updated by {Pa = r (Pb-C) + C} so that 1).

The value of r is transmitted when the product of (1-r) and the difference between the maximum value and the minimum value of the control range of the transmission power P increases or decreases the transmission power according to the control command. It is set to be smaller than the change in power.

Specifically, it is provided with a plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, and the mobile station is one or a plurality of base stations. In a base station device of a cellular system that performs communication by setting a line between the mobile station and the base station while the line is being set between the mobile station and one or more base stations. A first transmission for transmitting a control command of transmission power of the base station to the base station, the base station receiving the control command, and changing the transmission power according to the received control command to repeat a first transmission power control operation. Power control means, a second transmission power by which the base station updates the transmission power so that the absolute value of the difference between the decibel value of the predetermined reference power and the decibel value of the transmission power becomes small at a predetermined ratio. Second transmission power that repeats control operation Characterized by a control unit.

Further, the base station device of the cellular system of the present invention is characterized in that the reference power is the maximum transmission power of the transmission power.

[0044]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The transmission power control method for the cellular system according to the first embodiment is implemented in the cellular system having the configuration shown in FIG. In the cellular system of FIG. 1, the service area is divided into first and second cells 11 and 12, and first and second cells include first and second base stations 21 and 22, respectively. Being placed, the first
And there are second mobile stations 61, 62. The first and second base stations 21 and 22 are each connected to a control station 71, and the control station 71 is further connected to a communication network (not shown) including other control stations. Although not shown, this cellular system further includes a large number of base stations, and a large number of mobile stations are present in each cell.

The first and second base stations 21 and 22 transmit the first and second pilot signals 31 and 32 with constant transmission power, respectively. As will be described later, each mobile station 61, 62 is equipped with a measuring device for measuring the power of the pilot signal, and the first and second pilot signals 3
The received powers of 1 and 32 are measured, respectively. The mobile station switches the pilot signal measuring device in units of short time slots as shown in FIG. 2, and measures each pilot signal of a plurality of base stations once for each frame. In the example of FIG. 2, since there are 6 slots in one frame, pilot signals from up to 6 base stations can be measured.

When the mobile station moves, the instantaneous value of the received power fluctuates with a short period as time passes, as shown in FIG. Therefore, in order to obtain the median value, the mobile station measures the received power for a number of frames corresponding to a time sufficiently long with respect to the cycle of the instantaneous value fluctuation of the received power when the mobile station moves, Find the median of the measured values in the slots.

At the time of communication, a line is set up with the base station with the maximum median received power of pilot signals to start communication. During communication, the received power of the pilot signal may fluctuate as the mobile station moves.However, if the base station with the maximum median received power of the pilot signals changes, the base that sets the line Update the station.

In the first mobile station 61, assuming that the received power of the first pilot signal 31 is the maximum, the first mobile station 61
Mobile station 61 establishes a line with the first base station 21. The first downlink signal 41 is a signal to be transmitted from the first base station 21 to the first mobile station 61, and the first uplink signal 51 is from the first mobile station 61 to the first mobile station 61. It is a signal transmitted to the base station 21. On the other hand, in the second mobile station 62, the reception power of the first pilot signal 31 becomes maximum, and a line is set up with the first base station 21. At this time, the second mobile station 62 communicates with the first base station 21 by the second downlink signal 42 and the second uplink signal 52.

First and second downlink signals 41, 4
2, the first and second uplink signals 51 and 52 are both composed of repetition of a frame of a fixed length, and each frame is composed of a plurality of slots of shorter time. Has been done. The downlink signal slot contains a command for controlling the transmission power of the uplink signal, and the slot for the signal of the uplink contains a command for controlling the transmission power of the downlink signal. It is included.

FIG. 4 shows the first and second base stations 21 and 22.
2 shows the configuration of the base station device of FIG. The base station device is the antenna 2
01, transmission / reception duplexer 202, reception circuit 203, SIR measurement unit 204, transmission power control unit 205, transmission circuit 206,
Receiver circuit output terminal 207 and transmitter circuit input terminal 208
It consists of

The SIR measuring section 204 is a measuring device for measuring the ratio (SIR) of the desired wave power to the interference wave power of the uplink, and by this means, each time the mobile station receives a slot transmitted by the mobile station, the uplink Measure SIR.

FIG. 5 shows the first and second mobile stations 62, 62.
The structure of the mobile station apparatus of FIG. The mobile station device has an antenna 6
01, transmission / reception duplexer 602, reception circuit 603, SIR measurement 604, transmission power control unit 605, transmission circuit 606, reception circuit output terminal 607, transmission circuit input terminal 608, pilot signal power measuring instrument 612, and pilot signal terminal 613 It is configured.

The SIR measurement 604 is a measuring device for measuring the SIR of the downlink, and the SIR measurement 604 measures the downlink SIR each time the slot transmitted by the base station is received.

First, downlink transmission power control will be described.

In the mobile station, the downlink signal transmitted from the base station is received by the receiving circuit 603 via the antenna 601 and the transmission / reception duplexer 602. Each time the receiving circuit 603 receives a downlink signal slot,
The SIR measuring section 604 measures the downlink SIR of the downlink signal and obtains a measured downlink SIR value representing the downlink SIR. S
The IR measurement unit 604 determines the measured downlink SIR value and the target downlink SI.
Compare with R value. The measured downlink SIR value is the target downlink SIR
When it is smaller than the value, the SIR measurement section 604 outputs a downlink control command instructing an increase in downlink transmission power. When the measured downlink SIR value is larger than the target downlink SIR value, SIR measurement section 604 outputs a downlink control command instructing reduction of downlink transmission power. The downlink control command is supplied to the transmission circuit 606. The transmission circuit 606 transmits a downlink signal including a downlink control command for each slot to the base station via the transmission / reception duplexer 602 and the antenna 601.

In the base station, the uplink signal transmitted from the mobile station is received by the receiving circuit 203 via the antenna 201 and the transmission / reception duplexer 202. Every time the receiving circuit 203 receives a slot of an uplink signal,
The reception circuit 203 sends the downlink control command included in the slot to the transmission power control unit 205. Transmission power control unit 205
Calculates the downlink transmission power for the downlink signal for each slot using the downlink control command sent from the reception circuit 203, and sends the downlink transmission power control signal indicating the downlink transmission power to the transmission circuit 206. . In response to the downlink transmission power control signal, the transmission circuit 206 sets the downlink transmission power for the downlink signal to the value indicated by the downlink transmission power control signal. Then, the base station transmits the downlink signal generated by the transmission circuit 206 to one or more mobile stations via the duplexer 202 and the antenna 201.

Next, uplink transmission power control will be described.

In the base station, the uplink signal transmitted from the mobile station is received by the receiving circuit 203 via the antenna 201 and the transmission / reception duplexer 202. Every time the receiving circuit 203 receives a slot of an uplink signal,
The SIR measurement unit 24 measures the uplink SIR of the signal on the uplink and obtains a measured uplink SIR value representing the uplink SIR. SI
The R measurement unit 204 measures the measured upstream SIR value and the target upstream SIR.
Compare with the value. When the measured uplink SIR value is smaller than the target uplink SIR value, the SIR measurement section 204 outputs an uplink control command instructing an increase in uplink transmission power. Measurement up S
When the IR value is larger than the target upstream SIR value, the SIR measuring section 204 outputs an upstream control command instructing to reduce the upstream transmission power. The uplink control command is supplied to the transmission circuit 206. The transmission circuit 206 is connected to one or more mobile stations via the transmission / reception duplexer 202 and the antenna 201.
An uplink signal including an uplink control command is transmitted for each slot.

In the mobile station, the downlink signal transmitted from the base station is received by the receiving circuit 603 via the antenna 601 and the transmission / reception duplexer 602. Each time the receiving circuit 603 receives a downlink signal slot,
The receiving circuit 603 sends the uplink power control command included in the slot to the transmission power control unit 605. Transmission power control unit 605
Calculates the uplink transmission power for the uplink signal for each slot using the uplink control command sent from the reception circuit 603, and sends the uplink transmission power control signal indicating the uplink transmission power to the transmission circuit 606. . In response to the uplink transmission power control signal, the transmission circuit 606 sets the uplink transmission power for the uplink signal to the value indicated by the uplink transmission power control signal. Then, the mobile station transmits the uplink signal generated by the transmission circuit 606 to the base station via the transmission / reception duplexer 602 and the antenna 601.

Referring to FIG. 6 in addition to FIGS. 1 and 4, transmission power control for downlink signals by transmission power control section 205 of the base station will be described. Here, it is assumed that the downlink transmission power P is represented by a decibel value.

When the base station starts communication, it sets the downlink transmission power P for downlink signals to the initial value P0 (step S101). The initial value P0 is an arbitrary value within the control range of the transmission power. In step S102, the transmission power control unit 205 determines that the reception of the slot is successful every time the uplink signal transmitted from the mobile station receives the slot and the uplink SIR value of the slot is equal to or larger than a predetermined value. If the upstream SIR value of the slot is less than the predetermined value, it is determined that the slot reception has failed. In step S102, when the transmission power control unit 205 succeeds in receiving the slot, if the downlink control command in the slot has instructed to increase the power (step S10).
If YES in step 3, the downlink transmission power is increased by a predetermined value ΔP (S104), and if the power reduction is instructed (NO in step S103), the downlink transmission power is increased by a predetermined value ΔP. Decrease (S105). On the other hand, in step S102, if the slot reception has failed, the process proceeds to step S106.

Next, in step S106, the transmission power control unit 205 multiplies the difference r between the transmission power Pb before update and the predetermined reference power C (Pb-C) by the coefficient r.
The transmission power Pa is updated to r (Pb-C) + C so that (Pb-C) becomes equal to the difference (Pa-C) between the updated transmission power Pa and the predetermined reference power C. If the transmission power P is larger than the maximum power Pmax (step S
107), the transmission power P is set to the maximum power Pmax (S108), and when the transmission power P is smaller than the minimum power Pmin (YES in step S109), the transmission power P
Is the minimum power Pmin (S110). Then, the process is repeated again from step S102.

The predetermined reference power C is set so that most mobile stations in the cell can receive the downlink signal when the base station makes the downlink transmission power P of the downlink signal equal to the reference power C. , Set to a relatively high value within the control range of the transmission power P. In this embodiment, the downlink transmission power P is the maximum transmission power Pmax. The coefficient r is set in the range of 0 or more and less than 1, but the downlink transmission power P can be increased or decreased by the downlink control command from the mobile station, so that the downlink transmission power P is increased in step S106. The minute is set to be smaller than the increase / decrease amount ΔP of the transmission power in steps S104 and S105. Therefore, {r (P−C) + C} −P, which is the increment of the downlink transmission power P in step S106, that is,
(1-r) (C-P) is obtained in steps S104 and S105.
The value of the coefficient r is set so as to be smaller than the increase / decrease amount ΔP of the downlink transmission power P in. Further, the setting range of the coefficient r is 1−ΔP / (Pmax−P) <r <1. Here, for example, the difference between Pmax and Pmin is 10 dB, and ΔP is 1 d.
If B, then 0.9 <r <1. However, if the coefficient r is set to a value very close to 1, then step S1
Since the effect obtained by 06 becomes small, it is considered that the coefficient r should be set to about 0.95.

According to this method, when the propagation loss from the mobile station to the base station rapidly increases with the movement of the location of the mobile station, the state in which the communication between the base station and the mobile station is interrupted Communication can be continued without continuing. Considering the state in which the propagation loss from the mobile station to the base station rapidly increases, the base station fails to receive the uplink signal and cannot receive the control command included in the slot. When the reception of the slot of the signal of the line fails, the downlink transmission power P is brought close to the predetermined reference power C, so that if the reception of the slot fails continuously, the value becomes close to the reference power C. Since the reference power C is set to a value of relatively high transmission power within the control range of the downlink transmission power P, when the downlink transmission power P approaches the reference power C, the base station transmits in the mobile station. The downlink signal can be received. When the base station fails to receive the uplink signal, the base station SI
Since R is small, the mobile station is notified of an uplink control command for increasing the transmission power of the mobile station. However, when the mobile station can receive the downlink signal transmitted by the base station, the mobile station receives the uplink signal. Since the transmission power of the uplink signal is increased according to the control command, the base station can receive the uplink signal. In this way, bidirectional communication can be performed again between the base station and the mobile station, and the communication between the base station and the mobile station can be continued without being interrupted. it can.

In step S106, since the downlink transmission power Pa is updated to r (Pb-C) + C, (P-C) becomes r times for each time unit of the slot, so the downlink transmission power at a certain moment If P1 is set, after the update of step S106 is repeated n times while the downlink transmission power P is not changed in steps S104 and S105, (P-
C) is a value obtained by multiplying (P1−C) by the nth power of r. Since the coefficient r is less than 1, the nth power of the coefficient r gradually approaches 0. Therefore, the downlink transmission power P approaches the reference power C in step S106.

The base station cannot continuously control the downlink transmission power of the downlink signal due to the determination error of the downlink control command continuously, and the mobile station cannot receive the downlink signal accurately. Consider the case. In such a situation, the error in determining the downlink control command is random,
Generally, the probabilities of the downlink control command for instructing the increase of the downlink transmission power and the downlink control command for instructing the decrease thereof are almost the same. Therefore, in steps S104 and S105, the downlink transmission power P does not increase or decrease on average. However, according to this method, even in such a situation, the downlink transmission power P is brought close to the reference power C, and the mobile station can receive the downlink signal transmitted by the base station. As a result, in the same way as when the propagation loss from the mobile station to the base station suddenly increased, the two-way communication between the base station and the mobile station becomes possible again, and between the base station and the mobile station. The communication can be continued without the communication being interrupted.

In this embodiment, the mobile station sets up a line only with one base station, but the mobile station carries out a soft handover to set up a line with two or more base stations. Even in this case, each of the base stations controls the downlink transmission power in exactly the same manner as this embodiment, so that even if the propagation loss from the mobile station to the base station suddenly increases, the communication can be continued in the same manner. .

Next, another embodiment of the present invention will be described with reference to the drawings.

The transmission power control method for the cellular system according to the second embodiment is carried out in the cellular system having the configuration shown in FIG. In the cellular system of FIG. 7, the service area is divided into first and second cells 11 and 12, and first and second cells include first and second base stations 21A and 22A, respectively. Being placed,
There are first and second mobile stations 61A, 62A. The first and second base stations 21A and 22A are each connected to a control station 71A, and the control station 71A is further connected to a communication network (not shown) including other control stations. Although not shown, this cellular system further includes a large number of base stations, and a large number of mobile stations are present in each cell.

First and second base stations 21A and 22A
Respectively transmit the first and second pilot signals 31 and 32 with constant transmission power. Each mobile station 61A, 62
As will be described later, A has a measuring device for measuring the power of the pilot signal, and measures the received power of the first and second pilot signals 31, 32, respectively. The mobile station switches the pilot signal measuring device in units of short time slots as shown in FIG. 2, and measures each pilot signal of a plurality of base stations once for each frame. In the example of FIG. 2, there are 6 slots in one frame, so
It is possible to measure pilot signals from up to 6 base stations.

When the mobile station moves, the instantaneous value of the received power fluctuates in a short cycle with the passage of time as shown in FIG. Therefore, in order to obtain the median value, the mobile station measures the received power for a number of frames corresponding to a time sufficiently long with respect to the cycle of the instantaneous value fluctuation of the received power when the mobile station moves, Find the median of the measured values in the slots.

At the time of communication, a line is set up with a base station (hereinafter referred to as "main base station") having the maximum median received power of pilot signals to start communication. If there is a base station whose median value of pilot signal reception power is higher than the median value of pilot signal reception power of the main base station by a predetermined handover threshold value, then that base station (Hereinafter, referred to as “auxiliary base station”), a line is simultaneously set up for communication. During communication, the received power of the pilot signal may vary with the movement of the mobile station, but if the base station with the largest median received power of the pilot signal changes,
The main base station and the auxiliary base station are updated when the auxiliary base station no longer satisfies the condition and when another base station comes to satisfy the condition of the auxiliary base station.

Here, in the first mobile station 61A, for example, the reception power of the first pilot signal 31 is maximum, and the difference between the reception powers of the second pilot signal 32 and the first pilot signal 31 is handed over. It is assumed to be within a threshold value. In such a case, the first base station 21A becomes the main base station and the second base station 22A becomes the auxiliary base station. First
The primary downlink signal 41a and the first auxiliary downlink signal 41b are signals to be transmitted from the first base station 21A and the second base station 22A to the first mobile station 61A, respectively. The uplink signal 51 is a signal transmitted from the first mobile station 61A to the first and second base stations 21A and 22A.

On the other hand, in the second mobile station 62A, the reception power of the first pilot signal 31 becomes maximum, and the first base station 21 becomes the main base station. First pilot signal 31
The difference between the reception powers of the second pilot signal 32 and the second pilot signal 32 is larger than the handover threshold, and there is no auxiliary base station. At this time, the second mobile station 62A uses the second downlink signal 42 and the second uplink signal 52 to make the first
Communication with the base station 21A.

FIG. 8 shows the first and second base stations 21A and 2A.
The structure of the base station apparatus of 2A is shown. The base station device includes an antenna 201, a transmission / reception duplexer 202, a reception circuit 203, and an SI.
R measurement unit 204, transmission power control unit 205, transmission circuit 20
6, receiving circuit output terminal 207, and transmitting circuit input terminal 2
In addition to 08, a timer 210 and a timer terminal 211 are provided. The timer 210 measures the passage of time.

FIG. 9 shows the first and second mobile stations 62A, 6A.
The structure of the mobile station apparatus of 2A is shown. The mobile station device includes an antenna 601, a transmission / reception duplexer 602, a reception circuit 603, and an SI.
R measurement 604, transmission power control unit 605, transmission circuit 60
6, receiving circuit output terminal 607, transmitting circuit input terminal 60
8, a pilot signal power measuring device 612, and a pilot signal terminal 613, a timer 610, a timer terminal 611, and a cumulative control value updating unit 614. The timer 610 measures the passage of time. The cumulative control value updating unit 614 updates the cumulative control value as described later.

Referring to FIG. 10, the receiving circuit 603 has a receiving signal input terminal 603a and a receiving signal output terminal 603.
b, and the first to third base station signal receiving circuits 603-
1, 603-2, 603-3 and receiving base station control unit 603
-4 and a synthesizing unit 603-5. With such a configuration, the receiving circuit 603 can combine and receive the same signal transmitted from a plurality of base stations.

Referring to FIG. 11, the control station 71A has first and second base station connection input terminals 701, 70 connected to the first and second base stations 21A, 22A, respectively.
2 and the first and second base stations 21A and 22A, respectively.
First and second base station connection output terminals 70 connected to
With 3,704. The control station 71A has a notification receiving unit 70.
5, a reference value calculation unit 706, and a notification transmission unit 707.

Returning to FIG. 7, the operation of the cellular system shown in FIG. 7 will be described. As mentioned above, the first
The second base stations 21A and 22A operate as a main base station and an auxiliary base station, respectively, with respect to the first mobile station 61A that is performing the soft handover. The first base station 21A and the second base station 22A are
To the mobile station 61A, the signal 41 of the first main downlink signal, which is the same information except the uplink control command for the uplink transmission power.
a and the signal 41b of the first auxiliary downlink are transmitted respectively. The first mobile station 61A causes the receiving circuit 603 to
Of the main downlink signal 41a and the signal 41b of the first auxiliary downlink line are combined and received, and the SIR measuring unit 6
The down SIR is measured at 04. Then, the SIR measurement unit 604 compares the downlink measurement SIR value with the downlink target SIR value, and if the downlink measurement SIR value is smaller than the downlink target SIR value, the downlink control command is set to increase the power and the downlink measurement SIR value is increased. If the value is greater than the downlink target SIR value,
The downlink control command is power reduction. First mobile station 61A
Sends the downlink control command to the first and second base stations 21
Notify A and 22A. Similarly, the second mobile station 6
1A notifies the first base station 21A of the downlink control command. Then, the first and second base stations 21A and 22A
Performs downlink transmission power control by following the downlink control command.

The base station during the soft handover controls the downlink transmission power by using the reference power C commonly set among the base stations. The reference power C can be determined by a common method such as the maximum value, the minimum value, or an intermediate value between the maximum value and the minimum value of the downlink transmission power per line of the base station. Therefore, when the maximum value and the minimum value of the downlink transmission power set for each base station are different, the reference power C may have different values accordingly. However, in this embodiment, it is assumed that the control ranges of the downlink transmission power per line of all base stations are equal to each other and the reference powers C are also equal to each other.

On the other hand, in order to control the transmission power of the uplink, the first and second base stations 21A and 22A measure the uplink SIR for each slot, and when the uplink measured SIR value is smaller than the uplink target SIR value, If the uplink control command is power increase, and the uplink measured SIR value is larger than the uplink target SIR value, the uplink control command is power reduction and the mobile station is notified of the uplink control command. The second mobile station 62A controls the uplink transmission power according to the uplink control command transmitted by the first base station 21A that has set the line. On the other hand, the first mobile station 61A simultaneously sets up channels with the first and second base stations 21A and 22A, and therefore receives the uplink control commands transmitted by the two base stations, respectively. At this time,
When the contents of the two uplink control commands are different, the first mobile station 61A controls the uplink transmission power according to the uplink control command that further reduces the uplink transmission power.

Transmission power control for the downlink in the cellular system shown in FIG. 7 will be described with reference to FIG. 12 in addition to FIGS. 7 and 8. FIG. 12 is a flow chart in which the base station receives the downlink control command from the mobile station and determines the downlink transmission power of the downlink during execution of the soft handover. Here, the downlink transmission power P is represented by a decibel value.

When the base station starts the soft handover with the mobile station, if the base station is the main base station that has been transmitting to the mobile station before (step S2).
(NO of 01), the downlink transmission power P is the value immediately before the transmission power for the mobile station, and the base station is an auxiliary base station that has newly started transmission to the mobile station (step S201). YES), the downlink transmission power P is set to the initial value P0 (step S202). Further, the measurement time Tb of the timer 210 is initialized to 0 (step S
203). Here, the main base station and the auxiliary base station are notified of the frame number via the soft handover from the control station 71A, and the measurement time Tb is initialized when the frame is transmitted, so that the main base station and the auxiliary base station simultaneously. The timer 210 can be initialized. The initial value P0 is an arbitrary value within the control range of the downlink transmission power. The downlink control command is notified from the mobile station at regular intervals, and step S20
4, there is a newly notified downlink control command,
If the downlink control command indicates an increase in power,
The transmission power control unit 205 increases the downlink transmission power P by a predetermined value ΔP (steps S205 and S206),
When the downlink control command instructs power reduction, the transmission power control unit 205 sets the downlink transmission power P to a predetermined value Δ.
It is decreased by P (steps S205, S207).

Next, in step S208, when the measured time Tb of the timer 210 exceeds the time Tint, the transmission power control unit 205 determines that the downlink transmission power P before updating is P.
A value r (Pb-C) obtained by multiplying a difference r between b and a predetermined reference power C by a coefficient r is a difference (Pa) between the updated downlink transmission power Pa and the predetermined reference power C. The downlink transmission power P is updated to r (Pb−C) + C so that it becomes equal to −C) (step S209). In this embodiment, the time Tin
The t and the coefficient r are predetermined constant values, and the coefficient r is a value of 0 or more and less than 1. Well, the reference power C is an intermediate power (Pma) between the maximum power Pmax and the minimum power Pmin of the downlink transmission power P.
x + Pmin) / 2.

If the updated transmission power P is the maximum power Pma
When it is larger than x, the downlink transmission power P is set to the maximum power Pm.
If the updated transmission power P is smaller than the minimum power Pmin, the downlink transmission power P is set to the minimum power Pmin (step S212). And
The process is repeated from step S203 again.

In this embodiment, one mobile station performs soft handover with two base stations, but when one mobile station performs soft handover with three or more base stations, one mobile station On the other hand, each time the number of base stations performing soft handover increases, the measurement time Tb of the timer 210 is made uniform among the base stations by repeating the processing from step S201.

According to this method, since the initial values of the downlink transmission powers of the main base station and the auxiliary base station are different at the time of starting the soft handover, the downlink transmission power P1 of the main base station and the downlink transmission power of the auxiliary base station are different. Difference between power P2 | P1
-P2 | If one or more base stations fail to receive the downlink control command, these downlink transmission powers P
The difference | P1-P2 | between 1 and P2 may increase. However, control of steps S204 to S207, that is,
In the part of increasing or decreasing the downlink transmission power by the downlink control command from the mobile station, each base station receives the notification of the same downlink control command, so each base station fails to receive the downlink control command. Otherwise, the downlink transmission powers P1 and P2 are increased or decreased in the same manner, so that the difference | P1-P2 | between the downlink transmission powers P1 and P2 does not change.

On the other hand, every time the measurement time Tb of the timer 210 which is initialized at the same time elapses by the time Tint, the main base station and the auxiliary base station respectively set the downlink transmission powers P1 and P2 to r.
Since (P1-C) + C and r (P2-C) + C are updated at the same time, the difference between these downlink transmission powers P1 and P2 | P1-P2 |
Is r | P1-P2 |. In this way, the downlink transmission power difference | P1-P2 | becomes r times at each time Tint. Since the coefficient r is smaller than 1, unless the difference | P1−P2 | in the downlink transmission power increases due to the reception error of the new downlink control command, the difference in the control amount decreases in geometric progression to 0. Converge. Even if the downlink transmission power difference | P1-P2 | increases due to the occurrence of a new downlink control command reception error, the difference | P1-P2 | can be reduced.
Therefore, even if reception of the downlink control command fails, the transmission power Pi (i = 1, 2) of the downlink is transmitted between the base stations without exchanging information regarding the downlink transmission power between the base stations. It is possible to adjust the values to be almost equal to each other.

That is, after the downlink transmission power is increased or decreased by the control in the steps S204 to S207, the difference in the downlink transmission power of the plurality of base stations is reduced by the control in the steps S208 to S213. , The downlink transmission power is updated so as to approach the reference power C commonly set among a plurality of base stations.

As described above, while the mobile station is executing the soft handover, each base station transmits an uplink control command for uplink transmission power control to the mobile station with substantially equal power between the base stations. Therefore, when the propagation loss from each base station to the mobile station is almost the same, and there is a possibility that the propagation loss of the uplink is minimized in any base station, the mobile station can receive all the uplink control commands. . Therefore, the mobile station can control the uplink transmission power so that the desired wave power does not become excessive for any base station.

Further, the downlink transmission power of the base station is equal to the time Tin
Since it is controlled independently of the downlink control command for each t, at this time, even if the downlink control command increases the downlink transmission power, the downlink transmission power is decreased or, conversely, the downlink control command is downloaded. Even if it reduces the transmission power,
It may increase downlink transmission power. Downlink transmission power P
i (i = 1, 2) is updated to r (Pi-C) + C, and the change in downlink transmission power is | (1-r)
(C-Pi) |, and its maximum value is | (1-r)
(C-Pmin) | or | (1-r) (C-Pmax) |. In this embodiment, the reference power C is set to the central power (Pmax) between the maximum power Pmax and the minimum power Pmin of the downlink transmission power.
Since + Pmin) / 2, the maximum value of change can be reduced. Therefore, it is possible to reduce the influence of the downlink transmission power being insufficient due to the control for each time Tint and the reception quality being deteriorated, and the influence of increasing the downlink transmission power by increasing the downlink transmission power.

Next, another embodiment of the present invention will be described.

The transmission power control method of the cellular system according to the third embodiment is different from the method of determining the reference power C except that
This is the same as the second embodiment described above. In the third embodiment, the reference power C is the maximum power Pmax of the downlink transmission power.

Also in this embodiment, similarly to the second embodiment, even if the reception of the downlink control command fails, the information about the downlink transmission power is not exchanged between the base stations and the downlink transmission power is not exchanged. It is possible to adjust the transmission powers P i of the base stations to values approximately equal to each other between the base stations. In this embodiment, the downlink transmission power Pi (i = 1, 1) is set every time Tint.
By updating 2) with r (Pi-C) + C, the downlink transmission power is increased by (1-r) (Pmax-Pi). Therefore, in this method, the downlink transmission power does not become insufficient and the reception quality does not deteriorate.

The transmission power control method of the cellular system according to the fourth embodiment is different from the method of determining the reference power C except that
This is the same as the second embodiment described above. In the third embodiment, the reference power C is the minimum power Pmin of the downlink transmission power.

Also in this embodiment, similarly to the second embodiment, even if the reception of the downlink control command fails, the information regarding the downlink transmission power is not exchanged between the base stations and the downlink transmission power is not exchanged. It is possible to adjust the transmission powers P i of the base stations to values approximately equal to each other between the base stations. In this embodiment, the downlink transmission power Pi (i = 1, 1) is set every time Tint.
By updating 2) with r (Pi-C) + C, the downlink transmission power is reduced by (1-r) (Pi-Pmin). Therefore, in this method, the downlink transmission power does not become excessive and the downlink interference wave power does not increase.

Next, still another embodiment of the present invention will be described.

The transmission power control method for the cellular system of the fifth embodiment is the same as that of the second embodiment except for the method of determining the reference power C.

In the fifth embodiment, the main base station 21A for the mobile station 61A executing the soft handover is executed.
And the auxiliary base station 22A each simultaneously calculate the median value of the transmission power for the mobile station 61A in the same time period, and use the median value as the statistical value of the transmission power in the control station 71A.
To notify. The control station 71A includes the respective base stations 21
Reference power C based on the statistical value notified from A, 22A
Of the base stations 21A, 22
Notify A. Then, each base station 21
In A and 22A, when updating the transmission power for the mobile station 61A, the reference power C represented by the notified reference value is used.

According to this method, similarly to the second embodiment, even if the reception of the downlink control command fails, the downlink transmission power Pi can be adjusted to be substantially equal between the base stations. it can. Further, by setting the reference power C, which is a value in the range in which the downlink transmission power is fluctuating in practice, for each mobile station, the difference between the transmission power in practice and the reference power C becomes smaller. The variation of the downlink transmission power due to each update of the downlink transmission power becomes small, and the influence of the downlink transmission power becoming insufficient or excessive can be suppressed to a small level. Further, in the control station 71A, the control value (statistical value) notified from the main base station 21A is used as a reference value. However, since the main base station 21A has the smallest average value of the propagation loss up to the mobile station 61A, the control value Most reliable. Therefore, the variation of the downlink transmission power due to the update of the downlink transmission power for each time Tint can be further reduced.

Between the base stations 21A, 22A and the control station 71A, the statistical value of the downlink transmission power and the reference value representing the reference power C are exchanged, but these exchanges are compared with the control cycle of the transmission power control. Therefore, the amount of control information transmitted between the base stations 21A and 22A and the control station 71A is not a problem. Further, even if a delay time occurs, if the delay times are the same between the base stations 21A and 22A, the downlink transmission powers can be made equal to each other between the base stations 231A and 22A without any trouble. Therefore, the transmission amount of the control signal between the base stations 21A and 22A and the control station 71A does not increase so much, and the downlink transmission power fluctuates greatly, and the downlink transmission power becomes insufficient or excessive. The downlink transmission power is set to the base station 21 while suppressing the influence.
A and 22A can be equal to each other.

The transmission power control method of the cellular system of the sixth embodiment is the same as that of the fifth embodiment except the method of determining the reference power C in the control station 71A.

In the sixth embodiment, the control station 71A determines the maximum statistical value among the statistical values of the downlink transmission power notified from the respective base stations 21A and 22A as the standard value representing the standard power C. And notifies each of the base stations 21A and 22A.

In this embodiment, there is a difference in downlink transmission power between the base stations 21A and 22A due to a reception error of the downlink control signal, and the downlink transmission power notified from the respective base stations 21A and 22A to the control station 71A. When the statistic values of are different from each other, the reference value representing the reference power C is determined by using the statistic value of the base station whose downlink transmission power is increased. It is not decided to be small with respect to the value of the range in which the power is actually changing. Therefore, it is possible to reduce the possibility that the downlink transmission power will be insufficient at the time of updating the downlink transmission power for each time Tint, and to reduce the deterioration probability of the reception quality.

The transmission power control method for a cellular system according to the seventh embodiment is different from the base station in that the base station uses a constant coefficient r, but the coefficient is set individually by the mobile station. It is the same as the form.

In the seventh embodiment, the first coefficient r1 and the second coefficient r2 are provided as candidates for the coefficient r. However, the first
The coefficient r1 and the second coefficient r2 are both 0 or more and less than 1, but the second coefficient r2 is smaller than the first coefficient r1. The control station 71A includes the respective base stations 21
When the difference between the maximum value and the minimum value of the downlink transmission power statistics notified from A and 22A is smaller than a certain reference value, the first coefficient r1 is set as the coefficient r, and this is set to each base station. Notify the stations 21A and 22A. On the other hand, when the difference between the maximum value and the minimum value of the downlink transmission power statistical values notified from the respective base stations 21A and 22A is larger than a certain reference value, the second coefficient r2 is set as the coefficient r. , And notifies the base stations 21A and 22A of this. Then, the notified coefficient r is used in each of the base stations 21A and 22A.

According to this method, although the difference in downlink transmission power becomes r times every time Tint, the probability of reception error of the downlink control command notified from the mobile station to the base station is high, and the downlink transmission of the base station is high. When the difference between the electric powers is large, the coefficient r is set to a small value, so that the difference between the downlink transmission powers can be reduced in a short time. On the other hand, when the reception error probability of the downlink control command is low and the difference between the downlink transmission powers of the base stations is small, the coefficient r is set to a large value. It is possible to reduce the fluctuation amount and reduce the degree to which the downlink transmission power becomes insufficient or excessive.

The transmission power control method of the cellular system of the eighth embodiment is different in that the base station sets the time Tint individually by the mobile station instead of using the constant time Tint, and otherwise the fifth embodiment. This is the same as the embodiment.

In the eighth embodiment, the first time Tint1 and the second time Tint2 are provided as candidates for the time Tint. Here, the second time Tint2 is a value smaller than the first time Tint1. The control station 71A includes the respective base stations 21
When the difference between the maximum value and the minimum value of the downlink transmission power statistics notified from A and 22A is smaller than a certain reference value, the first time Tint1 is set as the time Tint and this is set to the respective bases. Notify the stations 21A and 22A. On the other hand, when the difference between the maximum value and the minimum value of the statistical values of the downlink transmission power notified from the respective base stations 21A and 22A is larger than a certain reference value, the control station 71A sets the second value as the time Tint.
Of time Tint2 of each base station 21
Notify A and 22A. Then, each base station 21
In A and 22A, the notified time Tint is used.

According to this method, although the downlink transmission power difference becomes r times at each time Tint, the probability of reception error of the downlink control command notified from the mobile station to the base station is high, and the downlink transmission of the base station is high. When the difference between the electric powers is large, the time Tint is set to a small value, so that the difference between the downlink transmission powers can be reduced quickly. On the other hand, when the probability of reception error of the downlink control command is low and the difference between the downlink transmission powers of the base stations is small, the time Tint is set to a large value. The frequency of update becomes small, and the frequency of the downlink transmission power becoming insufficient or excessive due to the variation due to the update can be made small.

The transmission power control method for the cellular system of the ninth embodiment is carried out in the cellular system having the configuration shown in FIG. 7, as in the second embodiment. Procedure in which each mobile station 61A, 62A measures the received power of the first and second pilot signals 31, 32 and sets a line between the main base station and the auxiliary base station when performing communication. Is also the same as the second embodiment. Each time the base stations 21A and 22A receive the slot transmitted by the mobile station, the SIR is measured and the mobile station 6
The method of measuring the SIR of each of the 1A and 62A each time it receives the slot transmitted by the base station is the same as in the second embodiment. Furthermore, the first base station 2 that is the main base station of the first mobile station 61A that is performing the soft handover.
1A and the second base station 22A, which is an auxiliary base station, are the same information as the first mobile station 61A except the downlink control command for downlink transmission power, which is the signal 41 of the first main downlink.
The point that a and the signal 41b of the first auxiliary downlink are respectively transmitted is also the same as in the second embodiment. First mobile station 6
1A combines and receives the downlink signals 41a and 41b, measures the downlink SIR, compares the measured downlink SIR value with the target downlink SIR value, and measures the measured downlink SI.
When the R value is smaller than the target downlink SIR value, the downlink control command is increased in power, and when the measured downlink SIR value is larger than the target downlink SIR value, the downlink control command is decreased in power, and the first mobile station 61A The downlink control command is notified to the first and second base stations 21A and 22A, and the second mobile station 6 is notified.
2A is also the same as the second embodiment in that the downlink control command is similarly notified to the first base station 21A. Also, the method of controlling the transmission power of the uplink is the same as that of the second embodiment.

The first mobile station 61A uses the timer 610.
(FIG. 9) is provided, and elapsed time can be measured.

The following flow chart will be used for explanation. In the flow chart and its explanation, electric power is treated as a decibel value.

FIG. 13 is a flow chart in which the mobile station 61A calculates the cumulative control value A and notifies it to the base station during execution of the soft handover. When the soft handover is started, the mobile station 61A also initializes the cumulative control value A to 0 (step S301), and measures the time Tm of the timer 610.
Is initialized to 0 (step S303). Then, every time a downlink control command is transmitted to the base station (Y in step S303).
If the downlink control command indicates an increase in power (ES) (YES in step S304), the cumulative control value A
Is increased by a predetermined value ΔA (step S305), and if the downlink control command indicates a power phenomenon (NO in step S304), the cumulative control value A is decreased by a predetermined value ΔA (step S306). . Next, the timer 61
When the measured time Tm of 0 has passed the time Tint (YES in step S307), the cumulative control value A is notified to each base station (step S308), and step S30 is performed.
Repeat from 2.

FIG. 14 is a flow chart in which the base station receives the downlink control command from the mobile station and determines the downlink transmission power of the downlink during execution of the soft handover. When the base station starts the soft handover with the mobile station, if the base station is the main base station that has already transmitted to the mobile station (NO in step S401), the downlink transmission power P is When the base station is the auxiliary base station that has newly started transmission to the mobile station while keeping the value immediately before the transmission power for the mobile station (YES in step S401), the downlink transmission power P is set to the initial value. It is set to P0 (step S402). As the initial value P0, an arbitrary value within the control range of the downlink transmission power can be selected, but here it is set to the maximum power Pmax of the downlink transmission power. The downlink control command is notified from the mobile station at regular intervals. In step S403, if there is a newly notified downlink control command and the downlink control command instructs power increase (YES in step S404), the transmission power control unit 205 determines the transmission power P of the downlink. Is increased by a predetermined value ΔP (step S405), and when the downlink control command instructs power reduction (NO in step S404), the transmission power control unit 2
05 reduces the downlink transmission power P by a predetermined value ΔP (step S406). Here, the predetermined value ΔP used in the base station is set equal to the predetermined value ΔA used in the mobile station.

Next, in step S407, when the cumulative control value A is received from the mobile station, the sum of the initial value P0 and the cumulative control value A is used as the reference power C (step S40).
8). Then, the transmission power control unit 205 determines that the value r (Pb-C) obtained by multiplying the difference (Pb-C) between the pre-update downlink transmission power Pb and the reference power C by the coefficient r is the post-update downlink transmission power Pa. The downlink transmission power P is updated to r (Pb-C) + C so that it becomes equal to the difference (Pa−C) between the reference power C and the reference power C (step S409). In this embodiment, the coefficient r is a predetermined constant value, and the coefficient r is a value of 0 or more and less than 1.

If the updated transmission power P is the maximum power Pma
If it is larger than x (YE in step S410)
S), the downlink transmission power P is set to the maximum power Pmax (step S411), and when the updated transmission power P is smaller than the minimum power Pmin (YES in step S412), the downlink transmission power P is set to the minimum power Pmin (step S412). Step S41
2). Then, the process is repeated again from step S403.

According to this method, when the soft handover is started, the difference | P1-P2 | between the downlink transmission power P1 of the main base station and the downlink transmission power P2 of the auxiliary base station.
However, if there is no reception error of the downlink control command, these downlink transmission powers P1 and P2 are transmitted each time the cumulative control value A is notified.
The difference | P1-P2 | Therefore, the transmission powers of the base stations can be made equal to each other.

Further, in this method, the update of bringing the downlink transmission power P closer to the reference power C is repeated, but the reference power C calculated by the sum of the initial value P0 and the cumulative control value A is the downlink transmission power in slot units. P increases or decreases in the same manner, so at the moment when the cumulative control value A is notified, the reference power C
And the downlink transmission power P substantially match. Therefore,
In a line in which no reception error occurs, the downlink transmission power P hardly changes due to the update of the downlink transmission power P, and the line in which the downlink transmission power P in which the reception error of the downlink control command has occurred has a value different from the reference power C Only in this case, the downlink transmission power P can be brought close to the reference power C. Therefore, when the downlink transmission power of the auxiliary base station whose channel quality is relatively poor differs from that of the main base station, it has almost no effect on the transmission power control of the major base station whose channel quality is often relatively good. , Only the downlink transmission power of the auxiliary base station will be corrected. In this way, when the downlink transmission powers are made equal to each other between the base stations, the influence of the downlink transmission power shortage or excess is reduced.

The flow charts of FIGS. 13 and 14 are as follows.
The same operation can be performed when the mobile station sets up a line with only one base station without executing soft handover. When the mobile station performs the control of FIG. 13 even when the mobile station sets up a line with only one base station, when a soft handover is started or when a new auxiliary base station is added. Even if the control is continued in exactly the same manner as in the flowchart of FIG. 13 without initializing the cumulative control value A, it can be implemented without any trouble.

The transmission power control method of the cellular system of the tenth embodiment is implemented in the cellular system having the configuration shown in FIG. 7, as in the second embodiment. Procedure in which each mobile station 61A, 62A measures the received power of the first and second pilot signals 31, 32 and sets a line between the main base station and the auxiliary base station when performing communication. Is also the same as the second embodiment. Each time the base stations 21A and 22A receive the slot transmitted by the mobile station, the SIR is measured and the mobile station 6
The method of measuring the SIR of each of the 1A and 62A each time it receives the slot transmitted by the base station is the same as in the second embodiment. Furthermore, the first base station 2 that is the main base station of the first mobile station 61A that is performing the soft handover.
1A and the second base station 22A, which is an auxiliary base station, are the same information as the first mobile station 61A except the downlink control command for downlink transmission power, which is the signal 41 of the first main downlink.
The point that a and the signal 41b of the first auxiliary downlink are respectively transmitted is also the same as in the second embodiment. First mobile station 6
1A combines and receives the downlink signals 41a and 41b, measures the downlink SIR, compares the measured downlink SIR value with the target downlink SIR value, and measures the measured downlink SI.
When the R value is smaller than the target downlink SIR value, the downlink control command is increased in power, and when the measured downlink SIR value is larger than the target downlink SIR value, the downlink control command is decreased in power, and the first mobile station 61A The downlink control command is notified to the first and second base stations 21A and 22A, and the second mobile station 6 is notified.
2A is also the same as the second embodiment in that the downlink control command is similarly notified to the first base station 21A. Also, the method of controlling the transmission power of the uplink is the same as that of the second embodiment.

The following flow chart will be used for explanation. In the flow chart and its explanation, electric power is treated as a decibel value.

FIG. 15 is a flow chart in which the base station receives the downlink control command from the mobile station and determines the downlink transmission power of the downlink during the execution of the soft handover. When the base station starts a soft handover with the mobile station, if the base station is the main base station that has been transmitting to the mobile station from the previous (NO in step S501), the downlink transmission power P is If the base station is the auxiliary base station that has newly started transmission to the mobile station (YES at step S501), the downlink transmission power P is set to the initial value. It is set to P0 (step S502). The initial value P0 is an arbitrary value within the control range of the downlink transmission power. A downlink control command is included in the slot transmitted by the mobile station to the base station. When the base station receives the slot from the mobile station (step S50)
3), if the downlink control command in the slot has instructed to increase the power (YE in step S504).
S), the transmission power control unit 205 increases the transmission power P of the downlink by a predetermined value ΔP (step S505), and when the downlink control command instructs the power reduction (NO in step S504), the transmission is performed. The power control unit 205 reduces the downlink transmission power P by a predetermined value ΔP (step S
506).

Next, the transmission power control section 205 multiplies the difference r (Pb-C) between the pre-update downlink transmission power Pb and the reference power C by the coefficient r to obtain the updated value r (Pb-C). The downlink transmission power P is updated to r (Pb-C) + C so that it becomes equal to the difference (Pa-C) between the downlink transmission power Pa and the reference power C (step S507). If the updated transmission power P is larger than the maximum power Pmax (step S508)
YES), the downlink transmission power P is set to the maximum power Pmax (step S509), and the updated transmission power P is set to the minimum power Pmi.
If it is smaller than n (YE in step S510)
S), and the downlink transmission power P is set to the minimum power Pmin (step S511). Then, the process is repeated from step S503.

In this embodiment, the reference power C is the maximum power Pmax of the downlink transmission power. The coefficient r is set to a value of 0 or more and less than 1, but the amount of increase in the downlink transmission power P in step S507 is set so that the downlink transmission power P can be increased or decreased by the downlink control command from the mobile station. Is set to be smaller than the increase / decrease amount ΔP of the transmission power in steps S505 and S506.
Therefore, {r (P−C) + C} −P, which is the increment of the downlink transmission power P in step S507, that is, (1-
The value of the coefficient r is set so that r) (CP) becomes smaller than the increase / decrease amount ΔP of the downlink transmission power P in steps S505 and S506. Further, the setting range of the coefficient r is 1−ΔP / (C−P) <r <1. In this embodiment, since the reference power C is the maximum power Pmax of the downlink transmission power, the setting range of the coefficient r is 1−ΔP / (Pmax−P) <r
<1. Here, for example, the difference between Pmax and Pmin is 10
If dB and ΔP are 1 dB, 0.9 <r <1. However, if the coefficient r is set to a value very close to 1, the effect obtained in step S507 becomes small, so it is considered preferable to set the coefficient r to about 0.95.

According to this method, as in the second embodiment, the initial values of the downlink transmission powers of the main base station and the auxiliary base station are different when the soft handover is started,
There is a difference | P1-P2 | between the downlink transmission power P1 of the main base station and the downlink transmission power P2 of the auxiliary base station. If one or a plurality of base stations fail to receive the downlink control command, the difference | P1-P2 | between the downlink transmission powers P1 and P2 may increase. However, steps S504 to S50
In the control of part 6, that is, in the part in which the downlink transmission power is increased or decreased by the downlink control command from the mobile station, each base station receives the notification of the same downlink control command. If the reception of the downlink control command does not fail, the downlink transmission powers P1 and P2 are similarly increased or decreased, so that the difference | P1-P2 | between the downlink transmission powers P1 and P2 does not change.

On the other hand, in the step S507, the main base station and the auxiliary base station update the downlink transmission powers P1 and P2 to r (P1-C) + C and r (P2-C) + C, respectively. Difference between downlink transmission powers P1 and P2 | P1-P2 |
Is r | P1-P2 |. In this way, the downlink transmission power difference | P1-P2 | becomes r times each time a slot is received. Since the coefficient r is smaller than 1, unless the difference | P1−P2 | between the downlink transmission powers P1 and P2 increases due to the reception error of the new downlink control command, the difference in the control amount decreases in geometric progression. Converge to 0. Further, even if a new downlink control command reception error occurs, the downlink transmission powers P1 and P2
Even if the difference | P1-P2 | of the difference increases, the difference | P1-P2 | can be decreased. Therefore, even if the reception of the downlink control command fails, the transmission power P of the downlink is transmitted between the base stations without exchanging information regarding the downlink transmission power with each other.
It is possible to set 1, P2 to be approximately equal to each other between base stations. In this way, the same effect as the second embodiment can be obtained.

It is needless to say that the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in all the embodiments described above, in order to control the transmission power of the uplink, instead of measuring the SIR at the base station, the desired wave power is measured and the uplink control of the uplink transmission power that cures the mobile station is performed. A method of determining the command so that the desired wave power is constant may be adopted.

[0130] Further, the downlink control command for the downlink transmission power control, which the mobile station notifies the base station, is information about a relative value change of increasing the downlink transmission power or decreasing the downlink transmission power. Although an example of a certain case is shown, the downlink control command may be an absolute amount instead of a relative change amount of the control amount of downlink transmission power.

In the above embodiments, an example of soft handover in which one mobile station sets up a line between two base stations has been described, but in the case of performing soft handover with three or more base stations. The present invention can be implemented in exactly the same manner.

Further, in the above embodiments, when the mobile station sets up a channel with a plurality of base stations, all the base stations have downlink transmission power according to the downlink control command from the mobile station. Although it is controlled to be equal to each other, the transmission power controlled to be equal to each other between the base stations in this way is set to the internal transmission power value, and the power actually transmitted at some base stations is A method of temporarily increasing or decreasing the internal reference power value as a reference is also conceivable.

For example, during execution of soft handover,
When a plurality of base stations transmit to one mobile station, a base station with a relatively large propagation loss from the mobile station performs downlink transmission even if it simultaneously transmits with the same transmission power as other base stations. While it does not contribute much to the improvement of reception quality in the mobile station, the effect of increasing the interference wave power with respect to other mobile stations is the same as that of other base stations. Therefore, in order to suppress the interference wave power, the base station in which the propagation loss from the mobile station has temporarily increased, temporarily sets the transmission power to a value smaller than the internal transmission power value, and the situation disappears. In that case, a method of returning the transmission power to be equal to the internal transmission power value can be considered.

As another example, in a system in which a base station transmits to a mobile station an uplink control command to increase or decrease the uplink transmission power of the mobile station, the base station controls the uplink transmission power of the mobile station to decrease. When sending a command, if the reception quality of the signal from the mobile station at the base station is excessive, set the downlink transmission power of the base station temporarily higher than the internal transmission power value. Then, in the case of other states, a method of returning the downlink transmission power to be equal to the internal transmission power value is also conceivable.

Even when the internal transmission power values that increase and decrease according to the downlink control command from the mobile station are made equal to each other among the base stations as in these methods, the present invention is carried out in exactly the same manner. be able to. Therefore, in the present invention, the transmission power control is not limited to the control of the power itself radiated from the antenna of the base station, but includes the control of the value of the transmission power internally handled by the base station.

Depending on the system, one slot transmitted by the base station contains a plurality of types of information such as a control command portion and a data portion, and the base station transmits with different power depending on the type. It is also possible to do.
In the present invention, it can be used to control the transmission power of a part of such a slot, or can be used to control the transmission power when the same transmission power is set for the entire slot.

In the second to tenth embodiments described above, the maximum transmission powers of the base stations are equal to each other, and therefore, the sizes of all cells are equal to each other. Even if the powers are different from each other and the cell sizes are different, the coefficient determined for each base station according to the maximum transmission power, the value obtained by multiplying the transmission power determined by the above embodiment with the power transmitted from the antenna, By doing so, the present invention can be implemented in exactly the same manner. When the coefficients determined for each base station are different from each other, according to the present invention, the transmission powers before being multiplied by the coefficients become close to each other, and the powers radiated from the antennas of the base stations have different values. However, using the value obtained by multiplying the coefficient determined by the base station as the transmission power is the same as when the amplifier or the attenuator is attached to the antenna or the fluctuation of the propagation loss, and accordingly, the cell boundary is also changed. Because of the variation, the diversity effect of the present invention and the like obtained at the cell boundary are all obtained in the same manner.

[0138]

As described in the above embodiments, according to the present invention, when the propagation loss between the base station and the mobile station suddenly increases, or when the downlink transmission power from the mobile station is increased in the base station. Even if the determination of the downlink control command is continuously erroneous, continuous communication can be performed without continuing the state in which the communication between the base station and the mobile station is interrupted.

Further, as described in the above embodiments, according to the present invention, during soft handover,
Even if the base station cannot correctly receive all downlink control commands for transmission power control transmitted from the mobile station,
The transmission powers of a plurality of base stations transmitting to one mobile station can be made equal to each other.

Therefore, there is a high probability that the mobile station can accurately receive the uplink control command for controlling the transmission power of the uplink from all the base stations that may minimize the propagation loss to the mobile station. Therefore, it is possible to control the transmission power of the uplink and increase the line capacity of the uplink. In addition, even if the base station with the minimum propagation loss is replaced at high speed, multiple base stations are transmitting at the same downlink transmission power, so the downlink diversity effect that the downlink reception quality is less likely to deteriorate Can be obtained.
Further, by preventing the transmission power of the downlink from becoming excessive, it is possible to suppress the increase of the interference wave, so that it is possible to increase the line capacity of the downlink. Further, in this control, the transmission amount with the control station does not become very large, and there is no problem even if there is a delay time in the exchange of the control signal with the control station. You don't even need a fast line between.

[Brief description of drawings]

FIG. 1 is a block diagram showing a cellular system to which a transmission power control method according to an embodiment of the present invention is applied.

FIG. 2 is a diagram showing a frame structure.

FIG. 3 is a diagram showing variations in received power due to fading.

FIG. 4 is a block diagram showing a configuration of a base station used in the cellular system shown in FIG.

5 is a block diagram showing a configuration of a mobile station used in the cellular system shown in FIG.

FIG. 6 is a flowchart showing transmission power control of the first embodiment.

FIG. 7 is a block diagram showing a cellular system to which a transmission power control method according to another embodiment of the present invention is applied.

8 is a block diagram showing a configuration of a base station used in the cellular system shown in FIG. 7.

9 is a block diagram showing a configuration of a mobile station used in the cellular system shown in FIG. 7.

10 is a block diagram showing a configuration of a receiving circuit used in the mobile station device shown in FIG.

11 is a block diagram showing a configuration of a control station used in the cellular system shown in FIG. 7.

FIG. 12 is a flowchart of a base station in the second to eighth embodiments.

FIG. 13 is a flowchart of a mobile station in the ninth embodiment.

FIG. 14 is a flowchart of the base station in the ninth embodiment.

FIG. 15 is a flowchart of a base station in the tenth embodiment.

[Explanation of symbols]

11,12 cells 21,22,21A, 22A base station 31, 32 Pilot signal 41, 41a, 41b, 42 Downlink signals 51,52 Uplink signal 61, 62, 61A, 62A mobile station 71,71A Control station 201 antenna 202 duplexer 203 receiver circuit 204 SIR measurement unit 205 transmission power control unit 206 Transmission circuit 207 Receiver circuit output terminal 208 Transmitter circuit input terminal 210 timer 211 timer terminal 601 antenna 602 transmitter / receiver 603 Receiver circuit 604 SIR measurement unit 605 Transmission power control unit 606 Transmission circuit 607 Receiver circuit output terminal 608 Transmit circuit input terminal 610 timer 611 timer terminal 612 Pilot signal power meter 613 Pilot signal terminal 614 Cumulative control value update unit 705 Notification receiver 706 Reference value calculation unit 707 Notification sending unit

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04B ^7/ 24-7/26 102 H04Q ^7/ 00-7/38

Claims (41)

(57) [Claims] 1. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a transmission power control method of a cellular system for performing communication by setting a line between the plurality of base stations, while the mobile station sets a line with one or more base stations, each of the plurality of base stations Each time a control command from the mobile station is received, the step of increasing or decreasing the transmission power according to the control command; and the transmission so that the transmission power of the base station after the increase or decrease approaches a predetermined reference power. Updating the power of the cellular system. 2. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a transmission power control method of a cellular system for performing communication by setting a line between the plurality of base stations, while the mobile station sets a line with one or more base stations, each of the plurality of base stations Each time a control command is received from the mobile station, the step of increasing or decreasing the transmission power P according to the control command, and the difference between the transmission power Pa of the base station after the increase or the decrease and a predetermined reference power C (Pa-C) is the transmission power Pb before update
And a difference (Pb-C) between the predetermined reference power C and r (0
{Pa = r (Pb−C) + C} such that ≦ r <1),
Updating the transmission power P. A method of controlling transmission power of a cellular system, comprising: 3. The amount of change in the transmission power when the product of the difference between the maximum value and the minimum value of the control range of the transmission power P and (1-r) increases or decreases the transmission power according to the control command. 3. The transmission power control method for a cellular system according to claim 2, wherein the r is set to be smaller than 4. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a transmission power control method of a cellular system for establishing communication between channels by setting a line between the mobile station and the base station while the mobile station sets up a line with one or more base stations. To the base station by transmitting a control command of the transmission power of the base station, the base station receives the control command and repeats the first transmission power control operation of changing the transmission power according to the received control command; A transmission power control method for a cellular system, characterized by repeating a second transmission power control operation for updating the transmission power so that the transmission power of the station approaches a predetermined reference power. 5. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a transmission power control method of a cellular system for establishing communication between channels by setting a line between the mobile station and the base station while the mobile station sets up a line with one or more base stations. To the base station by transmitting a control command of the transmission power of the base station, and the base station receives the control command and repeats the first transmission power control operation of changing the transmission power according to the received control command; The base station repeats a second transmission power control operation for updating the transmission power so that the absolute value of the difference between the decibel value of the reference power and the decibel value of the transmission power becomes small at a predetermined rate. Cellular system Transmission power control method. 6. The transmission power control method for a cellular system according to claim 1, wherein the reference power is the maximum transmission power. 7. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a transmission power control method for a cellular system in which a line is set between two base stations for communication, each of the plurality of base stations is configured to move while the mobile station sets a line with a plurality of base stations. Each time a control command is received from a station, the transmission power is increased or decreased according to the control command, and the difference between the transmission powers of the plurality of base stations after the increase or decrease is reduced and And updating the transmission power so that the transmission power approaches a reference power commonly set among the base stations. 8. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a transmission power control method for a cellular system in which a line is set between two base stations for communication, each of the plurality of base stations is configured to move while the mobile station sets a line with a plurality of base stations. Each time a control command is received from the station, the transmission power P is set according to the control command.
Increasing or decreasing the difference between the transmission power Pa of the base station after the increase or the decrease and a reference power C common between the plurality of base stations (Pa−
C) becomes r times (0 ≦ r <1) of the difference (Pb−C) between the transmission power Pb before update and the reference power C (Pa =
r (Pb−C) + C}, and the step of updating the transmission power P. A transmission power control method for a cellular system, comprising: 9. The change amount of the transmission power when the product of the difference between the maximum value and the minimum value of the control range of the transmission power P and (1-r) increases or decreases the transmission power according to the control command. 9. The transmission power control method for a cellular system according to claim 8, wherein the r is set so as to be smaller than the above. 10. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a transmission power control method of a cellular system for performing communication by setting a line between the mobile stations, while the mobile station is setting a line between a plurality of base stations, the mobile station of the plurality of base stations A first transmission power control for transmitting a transmission power control command of a base station to each of them, and changing the transmission power according to the control command received by each of the plurality of base stations. While repeating the operation, while reducing the difference in the transmission power of the plurality of base stations, updating the transmission power so that the transmission power approaches the reference power commonly set among the plurality of base stations Repeat transmission power control operation Transmission power control method of a cellular system characterized by and. 11. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a transmission power control method of a cellular system for performing communication by setting a line between the mobile stations, while the mobile station is setting a line between a plurality of base stations, the mobile station of the plurality of base stations A first transmission power control for transmitting a transmission power control command of a base station to each of them, and changing the transmission power according to the control command received by each of the plurality of base stations. While repeating the operation, the absolute value of the difference between the decibel value of the reference power and the decibel value of the transmission power commonly set among the plurality of base stations becomes small at a common ratio among the plurality of base stations. So that each of the plurality of base stations Transmission power control method of a cellular system characterized by repeating the second transmission power control operation for updating the serial transmission power. 12. The reference power is set to the maximum power of transmission power.
A method of controlling transmission power of a cellular system according to claim 1. 13. The cellular system according to claim 7, wherein the reference power is an intermediate power between a maximum power decibel value of the transmission power and a minimum power decibel value of the transmission power. Transmission power control method. 14. The reference power is the minimum power of the transmission power, and the reference power is 7, 8, 10 or 11.
A method of controlling transmission power of a cellular system according to claim 1. 15. Each of the plurality of base stations calculates a statistical value of transmission power and notifies the control station, and the control station uses the statistical value of the plurality of base stations to calculate the reference power. 9. The reference value representing the above is calculated and notified to the plurality of base stations, and the plurality of base stations use the reference power represented by the notified reference value. Alternatively, the transmission power control method of the cellular system according to Item 10. 16. The transmission power control method for a cellular system according to claim 15, wherein the maximum statistical value of the statistical values is used as the reference value. 17. Each of the plurality of base stations calculates a statistical value of transmission power and notifies the control station, and the control station uses the statistical value of the plurality of base stations to calculate the reference power. 12. The reference value representing is calculated and notified to the plurality of base stations, and the plurality of base stations use the reference power represented by the notified reference value. Power control method for cellular system of the above. 18. The transmission power control method for a cellular system according to claim 17, wherein the maximum statistical value of the statistical values is used as the reference value. 19. The transmission power of a cellular system according to claim 17, wherein the control station determines the common ratio according to a mutual difference of the statistical values of the plurality of base stations. Control method. 20. The control station determines a frequency of updating the transmission power by the common ratio according to a difference between the statistical values of the plurality of base stations. A method of controlling transmission power of a cellular system according to claim 1. 21. The mobile station has information on a cumulative control value of transmission power of a base station, updates the cumulative control value each time a control command of the transmission power of the base station is transmitted, and determines the transmission power. Transmitting to the plurality of base stations at a time interval longer than the repeating time interval of the updating operation, and using the received cumulative control value, the plurality of base stations determine and use the reference power. The transmission power control method for a cellular system according to claim 7, 8, 10, or 11. 22. The transmission power control method for a cellular system according to claim 7, 10 or 11, wherein the plurality of base stations update the transmission power at the same time. 23. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a base station device of a cellular system that establishes a line between two base stations and performs communication, while the mobile station sets a line with one or more base stations, receives a control command from the mobile station. Each time, the transmission power is increased or decreased according to the control command, and the transmission power of the base station after the increase or decrease is updated so that the transmission power approaches a predetermined reference power. A base station device of a characteristic cellular system. 24. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a base station device of a cellular system that establishes a line between two base stations and performs communication, while the mobile station sets a line with one or more base stations, receives a control command from the mobile station. Each time, the means for increasing or decreasing the transmission power P according to the control command, and the difference (Pa-C) between the transmission power Pa of the base station after the increase or the decrease and the predetermined reference power C is Transmission power Pb
And a difference (Pb-C) between the predetermined reference power C and r (0
{Pa = r (Pb−C) + C} such that ≦ r <1),
And a means for updating the transmission power P. 25. A change in the transmission power when the product of the difference between the maximum value and the minimum value of the control range of the transmission power P and (1-r) increases or decreases the transmission power according to the control command. The base station apparatus of the cellular system according to claim 24, wherein the r is set to be smaller than the minutes. 26. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a base station device of a cellular system that performs communication by setting a line between the mobile station and the mobile station while setting a line with one or more base stations, Transmitting the control command of the transmission power of the base station, the base station receives the control command, and changes the transmission power according to the received control command A cellular unit comprising: a control unit; and a second transmission power control unit that repeats a second transmission power control operation for updating the transmission power so that the transmission power of the base station approaches a predetermined reference power. System base station equipment. 27. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a base station device of a cellular system that performs communication by setting a line between the mobile station and the mobile station while setting a line with one or more base stations, Transmitting the control command of the transmission power of the base station, the base station receives the control command, and changes the transmission power according to the received control command Control means and a second transmission power control for updating the transmission power by the base station so that the absolute value of the difference between the decibel value of the predetermined reference power and the decibel value of the transmission power becomes small at a predetermined ratio. Second transmission power control that repeats operation The base station apparatus of a cellular system characterized by a means. 28. The base station device of a cellular system according to claim 23, 24, 26 or 27, wherein the reference power is the maximum power of transmission power. 29. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a base station device of a cellular system that performs communication by setting a line between the mobile stations, while the mobile station is setting a line between a plurality of base stations, each time a control command is received from the mobile station. , A means for increasing or decreasing the transmission power according to the control command, and reducing the difference in the transmission power of the plurality of base stations after the increase or the decrease, and the transmission power is commonly set between the plurality of base stations. Means for updating the transmission power so that the transmission power approaches the reference power. 30. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a base station device of a cellular system that performs communication by setting a line between the mobile stations, while the mobile station is setting a line between a plurality of base stations, each time a control command is received from the mobile station. Means for increasing or decreasing the transmission power P according to the control command, and a difference (Pa-
C) is r times (0 ≦ r <1) of the difference (Pb−C) between the transmission power Pb before update and the reference power C, {Pa =
r (Pb-C) + C}, and means for updating the transmission power P, a base station apparatus of a cellular system. 31. A difference between the maximum value and the minimum value of the control range of the transmission power P and a product of (1-r) and a change amount of the transmission power when the transmission power is increased or decreased according to the control command. The base station apparatus of the cellular system according to claim 30, wherein the r is set to be smaller than 32. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a base station device of a cellular system that performs communication by setting a line between the mobile stations, while the mobile station is setting a line between a plurality of base stations, the mobile station each of the plurality of base stations A first transmission power control operation of transmitting a transmission power control command of a base station to the base station, and changing the transmission power according to the control command received by each of the plurality of base stations. And a first transmission power control unit that repeats, reducing the difference in transmission power of the plurality of base stations, and the transmission power so that the transmission power approaches a reference power commonly set among the plurality of base stations. Second transmission power control motion to update The base station apparatus of a cellular system and having a second transmission power control means to repeat. 33. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station comprises one or a plurality of base stations. In a base station device of a cellular system that performs communication by setting a line between the mobile stations, while the mobile station is setting a line between a plurality of base stations, the mobile station each of the plurality of base stations A first transmission power control operation of transmitting a transmission power control command of a base station to the base station, and changing the transmission power according to the control command received by each of the plurality of base stations. First transmission power control means to repeat, the absolute value of the difference between the decibel value of the reference power and the decibel value of the transmission power commonly determined between the plurality of base stations between the plurality of base stations The plurality of groups so that they are reduced in a common proportion. The base station apparatus of a cellular system in which each station is characterized by having a second transmission power control means for repeating the second transmission power control operation for updating the transmission power. 34. The base station device of a cellular system according to claim 29, 30, 32 or 33, wherein the reference power is the maximum power of transmission power. 35. The reference power is set to an intermediate power between a maximum power decibel value and a minimum power decibel value of the transmission power.
The base station device of the cellular system according to. 36. The base station apparatus of the cellular system according to claim 29, 30, 32 or 33, wherein the reference power is a minimum power of transmission power. 37. A plurality of cells, a plurality of base stations respectively arranged in the plurality of cells, and a mobile station moving in each cell, wherein the mobile station is one or a plurality of base stations. A control station used in a cellular system for setting communication between the base stations, the control station being connected to the plurality of base stations, the control station transmitting power from the plurality of base stations. Receiving means for receiving the statistic value of, the calculation means for calculating the reference value representing the reference power using the received statistic value, and a transmitting means for transmitting the calculated reference value to the plurality of base stations, A control station for a cellular system, comprising: 38. The control station of the cellular system according to claim 37, wherein the maximum statistical value of the statistical values is used as the reference value. 39. The calculating means determines the common ratio used by the plurality of base stations according to a mutual difference of the statistical values of the plurality of base stations. The control station of the cellular system according to. 40. The calculation means determines the frequency of updating the transmission power of the plurality of base stations by a common ratio according to the mutual difference of the statistical values of the plurality of base stations. The control station of the cellular system according to claim 37. 41. A mobile station used in a cellular system comprising a plurality of cells and a plurality of base stations respectively arranged in the plurality of cells, wherein the mobile station moves in each cell. And establish communication with one or a plurality of base stations, the mobile station has information on a cumulative control value of transmission power at the base station, and the mobile station has the cumulative control. A means for updating the value every time a control command of the transmission power of the base station is transmitted, and an updated cumulative control value, which is stored in the plurality of base stations at a time interval longer than the repeating time interval of the update operation of the transmission power. A mobile station of a cellular system having means for transmitting.