KR20050020547A - Node b scheduling method in mobile communication system - Google Patents

Abstract

PURPOSE: A base station scheduling method in a mobile communication system is provided to be applied to an uplink base station scheduling function of terminals which are soft handed over with plural base stations, thereby preventing performance deterioration while more effectively controlling an uplink noise rise in each base station. CONSTITUTION: A BSC determines proper weights of each terminal which is soft handed over, based on uplink related information(S10), and periodically informs a scheduling base station of the determined weights(S11). The scheduling base station analyzes a self noise rise to calculate a 'current tolerable noise rise', and determines transmit powers of the terminals, then applies the weights when determining a final transmit power(S12). The base station performs a scheduling process by directly informing each terminal of the determined final transmit power or by increasing/decreasing a current transmit power(S13).

Description

Base station scheduling method in mobile communication system {NODE B SCHEDULING METHOD IN MOBILE COMMUNICATION SYSTEM}

The present invention relates to a wireless mobile communication system, and more particularly, to a base station scheduling method applicable to an uplink channel.

Currently, in the 3GPP wireless mobile communication system, various discussions on the application of the Enhanced Uplink Dedicated Channel (E-DCH) have been actively conducted according to the demand for uplink speed. Among them, the base station (Node B) -based uplink scheduling scheme is an important issue of the E-DCH.

Conventional uplink scheduling and rate control is performed by a scheduler existing in a radio network controller (RNC). However, the RNC scheduler does not quickly cope with uplink load change. In contrast, the Node B scheduler (hereinafter referred to as a base station) can quickly control the uplink load by adjusting the transmission power and transmission rate of each user equipment (UE, hereinafter referred to as a terminal) in response to the uplink load change. As a result, the base station scheduler can cope with the change in the uplink load quickly to reduce the noise rise variance so that the noise rise margin of the uplink can be relatively small. This translates into increased cell throughput and cell coverage expansion.

However, since the transmission signal of the terminal in the soft handover situation has a large influence on the uplink load of a plurality of base stations at the same time, it is difficult to effectively schedule the base station.

The base station scheduling technique is to perform the role of the scheduler existing in the existing base station controller (RNC) in place of the base station. One of the major problems that arise at the time of scheduling at the base station is that it is not possible to know the fluctuations in noise rise due to mutual information exchange between the base stations. In particular, in a handover situation, since each base station participating in the scheduling sends a scheduling command to the terminal based on its noise rise variation, the terminal often cannot meet the requirements of all the base stations participating in the scheduling.

In such a situation, there may be a method according to a scheduling request of a specific base station and a method of properly combining a scheduling request from several base stations to determine a next operation by the terminal. However, no satisfactory scheduling technique has been proposed yet.

Accordingly, an object of the present invention is to provide a base station scheduling method capable of controlling uplink load in a soft handover situation.

A wireless system for scheduling a terminal in which the base station is in a soft handover state in order to achieve the above object, the base station scheduling method according to the present invention comprises the steps of the base station controller to select a base station to perform uplink scheduling; Delivering weights for scheduling to the selected base station; Performing scheduling for each terminal in soft handover using the transferred weight.

The base station scheduling method further includes determining, at the base station, a weight to be used for scheduling of each terminal.

Preferably, the weight is determined in consideration of a geopolitical relationship or a path loss between the terminal and the base stations in soft handover.

Preferably, as the transmission power of the terminal in the soft handover has a greater effect on uplink noise rise of other base stations in soft handover but does not schedule the terminal, a weight to be applied to each terminal is determined as a small value. Smaller is characterized by determining a larger value.

Preferably, the base station performs transmission power and rate scheduling based on its noise rise and the transferred weight.

Preferably, the weight is determined by the following formula, Denotes a path loss between the base station N and the terminal X, and the base station A is a scheduling base station.

Preferably, the weighting step includes selecting one base station in soft handover and calculating two-way handover weights of the selected base station and the scheduling base station; When all the weights are obtained by the calculation, it is determined that one of them is determined as the weight of the corresponding terminal.

Preferably, the base station controller is characterized by determining the maximum value of the weights obtained by the calculation as the weight of the terminal.

Preferably, the base station controller is characterized by determining the minimum value among the weights obtained by the calculation as the weight of the terminal.

In order to achieve the above object, in a wireless system for scheduling a terminal in which the base station is in a soft handover state, the base station scheduling method according to the present invention comprises the steps of selecting a base station for the base station controller to perform uplink scheduling; ; Delivering a scheduling limit value for scheduling to the selected base station; Performing scheduling for each terminal in soft handover so as not to exceed the delivered scheduling limit.

The base station scheduling method further includes the step of determining, by the base station controller, a scheduling limit value to be used for scheduling of each terminal.

Preferably, the scheduling limit value is a limit value of a transmission power or a transmission rate.

Preferably, the scheduling limit value is determined in consideration of the geopolitical relationship or the path loss between the terminal and the base station in soft handover.

Preferably, as the transmission power of the terminal in soft handover does not schedule the terminal but has a greater effect on the uplink noise rise of other base stations in soft handover, the scheduling limit value to be applied to each terminal is determined to be a small value. , The smaller the value is, the larger the value is determined.

In order to achieve the above object, in a wireless system for scheduling a terminal in which a plurality of base stations are in a soft handover state, the base station scheduling method according to the present invention selects a plurality of base stations to perform uplink scheduling in the base station controller. Steps; Transmitting a selection probability of each selected base station to the terminal; Selecting one of the scheduling commands transmitted from the plurality of base stations by the terminal using the selection probability of each base station transmitted.

Advantageously, the base station scheduling method further comprises determining, at a base station controller, a selection probability of each base station to be used by each terminal.

Preferably, the selection probability is determined in consideration of the geopolitical relationship or the path loss between the terminal and the base stations in soft handover.

Preferably, the selection probability is obtained by the following formula, Denotes a path loss between the base station N and the terminal X, Is characterized in that it means that the selection probability of the base station (N) to be used for the terminal (X).

Preferably, the selection probability determining step includes selecting one of a plurality of scheduling base stations and calculating related selection probabilities of the selected base station and another scheduling base station; When all the selection probabilities are obtained by the calculation, the selection probabilities are all determined as the selection probabilities of the selected base station.

Preferably, when the determined selection probabilities are transmitted to the terminal, the terminal determines a maximum value among the transmitted selection probabilities as the selection probability of the corresponding base station.

Preferably, when the determined selection probabilities are transmitted to the terminal, the terminal may determine a minimum value among the transmitted selection probabilities as the selection probability of the corresponding base station.

Preferably, the base station scheduling method further includes the step of transmitting a scheduling command by determining the transmission power of the terminal to be scheduled in accordance with the noise rise at the base stations.

Hereinafter will be described a preferred embodiment of the present invention.

The present invention is implemented in a W-CDMA mobile communication system. However, the present invention can also be applied to communication systems operating according to other standards. Hereinafter, preferred embodiments of the present invention will be described in detail.

The present invention proposes a new algorithm capable of efficiently performing Node B scheduling for an enhanced uplink dedicated channel (E-DCH) in a 3GPP wireless mobile communication system.

1. First embodiment of the present invention

A first embodiment of the present invention is a method according to a scheduling request of a specific base station. That is, the first embodiment of the present invention is a method applicable to the case where the UE is in soft handover with a plurality of base stations Node B, but receives a scheduling command from only one base station. In this case, which base station is scheduled for each terminal in soft handover may be appropriately determined by using a radio network controller (RNC, hereinafter referred to as a base station controller) using information on each base station and terminals.

The base station controller determines the weight to be applied to the scheduling of each terminal and informs the base station scheduling each terminal. At this time, the base station controller determines that the weight to be applied to each terminal is smaller as the transmission power of the terminal does not schedule the terminal but has a greater effect on the uplink noise rise of neighboring base stations in soft handover with the terminal. The smaller the value, the larger the value.

The base station determines a final transmission power or transmission rate to be scheduled to the terminal by applying a weight received from the base station controller to the transmission power or transmission rate allocated to the terminal in the soft handover state.

This makes it possible to more efficiently control the uplink noise rise of all base stations by equalizing the influence on the noise rise of neighboring base stations by the scheduling of each base station.

As an example of determining a weight of a plurality of base stations and a terminal in soft handover, the base station controller determines a path loss between the terminal and a path loss for the scheduling base station of the terminal and other base stations in soft handover. The ratio can be used to determine the weight. In addition, the present invention is not limited thereto, and the weight may be determined in consideration of geopolitical relationships between base stations in soft handover.

end. 2-way handover

FIG. 1A illustrates an example of determining weights for two base stations and terminals in soft handover. For convenience of description, it is assumed that both the terminal 1 and the terminal 2 are in soft handover state with the base stations 10 and 12 but are receiving a scheduling command only by the base station 10.

As shown in FIG. 1A, path-losses for the base stations 10 and 12 of the terminal 1 are LA, 1, LB, and 1 for the base stations 10 and 12 of the terminal 2, respectively. If the path loss is LA, 2, LB, 2, respectively, the weights W1 and W2 for UE 1 and UE 2 may be determined as follows.

--------------- [Equation 1]

(A, B: identification number of base station (node B), 1,2: identification number of terminal)

According to the above equations, the terminal 1 having a relatively small path loss LB 2 with respect to the base station 12 is assigned a smaller weight than the terminal 2 having a large path loss with respect to the base station 12. Therefore, on average, terminal 1 is scheduled to have a lower transmission power or a lower transmission rate than terminal 2. As a result, the influence of the terminals scheduled by the base station 10 on the base station 12 is reduced and leveled, thereby preventing the noise rise of the base station 12 from being unstable by the terminal 1 and the terminal 2.

I. 3-way handover

FIG. 1B is a diagram illustrating an example of determining weights for three base stations and a terminal in soft handover. For simplicity, only terminal 1 is shown in the drawings, and for convenience of description, terminal 1 and terminal 2 are in soft handover state with the base stations 10, 12, and 14, but are scheduled only by the base station 10. Assume that you are receiving.

As shown in FIG. 1B, path-losses for the base stations 10, 12, and 14 of the terminal 1 are LA, 1, LB, 1, LC, 1, respectively, and the base station 10 of the terminal 2 , 12, 14, the path loss is LA, 2, LB, 2, LC, 2, respectively, the weight (W1, W2) for the terminal 1 and terminal 2 can be determined as follows.

------------ [Equation 2]

All. n-way handover

By further expanding the above [Equation 1] and [Equation 2], it is expressed as a weight expression for the terminal 1 and terminal 2 in soft handover with n base stations as follows.

                                        --------------- [Equation 3]

Hereinafter, the base station scheduling method according to the first embodiment of the present invention will be described in detail with reference to the flowchart of FIG. 2. FIG. 2 illustrates a case in which only one base station of soft handover performs scheduling for a terminal when an arbitrary terminal is in soft handover state with a plurality of base stations.

First, the base station controller determines an appropriate weight of each terminal in soft handover based on uplink related information of the scheduling base station and other base stations in handover (S10), and then periodically (or changes in weights) the scheduling base station. Every time it is requested) (S11).

The scheduling base station analyzes its noise rise, calculates its own " current allowable noise rise amount ", and then determines transmission power (or transmission rate) of terminals to which it should be scheduled based on the calculated value. At this time, the scheduling base station applies the weight to the final transmission power (or transmission rate) determination for the terminal in soft handover (S12).

Finally, the base station may perform scheduling by directly informing each terminal of the determined final transmission power (or transmission rate) through a scheduling command, or increasing or decreasing the current transmission power (or transmission rate) of the terminal based on this. There is (S13).

2. Second embodiment of the present invention

Similar to the first embodiment, the second embodiment of the present invention is applicable to a case where the terminal is in soft handover with a plurality of base stations but receives a scheduling command only by a single base station.

The weight (W) calculation according to the second embodiment is to calculate the weight of the 2-way handover when obtaining the weight in the 3-way handover (2-way handover) and more handover situation It differs from the first embodiment in that the method is applied.

The method of claim 2, wherein the determining of the weight

That is, the base station controller selects one base station that is in soft handover and calculates two-way handover weights of the selected base station and the scheduling base station. When all the weights are obtained by the calculation, one of them is determined as the weight of the corresponding terminal.

For example, assuming that the scheduling base station is referred to as base station A, and adjacent base stations in handover with the base stations B and C, the base station controller obtains a weight between the base station A and the base station B, and calculates the weight between the base station A and the base station C. Obtain

In a 3-way or more handover situation, the weight for each terminal is n-1 (n is the number of all base stations being handed over with the terminal). Once all the weights are found, the base station controller forwards these weights to the scheduling base station, which schedules one of the weights.

The scheduling base station applies the selected weight to the transmission power (or transmission rate) allocated to the terminal in the soft handover state.

According to the second embodiment, the weight may be expressed by the following equation. (For convenience of description, only the equation for the terminal 1 will be shown.)

end. 2-way handover

--------------- [Equation 4]

I. 3-way handover

------------------- [Equation 5]

= {MIN ( ) or MAX ( )} --------- [Equation 6]

Equation 5 is a weight calculation formula of 3-way handover. [Equation 6] shows a weight selection method of the scheduling base station. The scheduling base station selects the maximum value or the minimum value among the weight values of [Equation 5].

All. n-way handover

[Equation 7]

(Eq. 8)

= {MIN ( ) or MAX ( )}

Equation 7 is a weight calculation formula of n-way handover. [Equation 8] shows a weight selection method of the scheduling base station. The scheduling base station selects the maximum value or the minimum value among the weight values of [Equation 7].

3. Third embodiment of the present invention

Similar to the first and second embodiments, the third embodiment of the present invention is applicable to a case where the terminal is in soft handover with a plurality of base stations but receives a scheduling command only by a single base station.

In the third embodiment of the present invention, as shown in FIG. 3, the base station controller determines a limit value of the transmission power (or transmission rate) to be applied to the scheduling of each terminal for terminals that are in soft handover with a plurality of base stations ( S20), and informs the base stations scheduling each terminal (S21).

Accordingly, the base station performs scheduling for the terminal so that the transmission power (or transmission rate) allocated to each terminal in the soft handover state is always kept below the limit value (S22), (S23).

As in the first embodiment, in the second embodiment, in the second embodiment, the base station controller has a higher transmission power of a terminal that is in soft handover, but does not schedule the terminal, but has a greater effect on the uplink noise rise of neighboring base stations in soft handover. The smaller the limit value to be applied to, the smaller the value is. In addition, the limit value may be determined in consideration of the geopolitical relationship between the terminal and the base stations in soft handover.

This minimizes the effect of scheduling of each base station on the noise rise of neighboring base stations, thereby more efficiently controlling the uplink noise rise of all base stations.

4. Fourth embodiment of the present invention

A fourth embodiment of the present invention is a method of properly combining scheduling requests from various base stations to determine a next operation by the terminal. That is, unlike the first, second, and third embodiments, the fourth embodiment of the present invention is applicable to a case where the terminal receives a scheduling command from all base stations in soft handover. At this time, both the terminal and the base stations in soft handover transmit a scheduling command to the terminal, and the terminal determines the final transmission power and transmission rate.

To this end, the base station controller determines a selection probability for each base station of the terminal that is in soft handover with the base station and informs the terminal. The base station controller determines the selection probability as a smaller value as the influence of the transmission power of the terminal in soft handover on the uplink noise rise of the other base stations in soft handover is greater, and as the value is smaller as a larger value.

Each base station in soft handover with the terminal transmits a scheduling command to the terminal according to its uplink noise rise. The terminal receives the scheduling commands from the base stations in soft handover, and randomly selects one scheduling command by applying a selection probability for each base station from the base station controller.

This makes it possible to equalize the effect of the scheduling of each base station on the noise rise of neighboring base stations, resulting in more efficient control of the uplink noise rise of all base stations.

As described above, the base station controller determines a selection probability for each base station of a plurality of base stations and a terminal in soft handover by using a ratio between path losses of base stations in soft handover.

end. 2-way handover

4A illustrates an example in which two base stations and a terminal in soft handover determine a selection probability for each base station. For convenience of description, it is assumed that both the terminal 1 and the terminal 2 are in a soft handover state with the base stations 20 and 22 and both are receiving a scheduling command from the base stations 20 and 22. In addition, path losses for the base stations 20 and 22 of the terminal 1 are LA, 1, and LB, 1, and path losses for the base stations 20 and 22 of the terminal 2 are LA, 2, LB, and 2, respectively. In this case, the selection probabilities PA, 1, PB, 1 for the base stations 20 and 22 of the terminal 1 and the selection probabilities PA, 2, PB, 2 for the base stations 20 and 22 of the terminal 2 are referred to. Each can be defined in the following way.

[Equation 9]

** Selection probability for base stations 20 and 22 that are in handover with terminal 1 **

** Selection probability for base stations 20 and 22 handing over with terminal 2 **

By doing so, the terminal 1 having a relatively low path loss for the base station 22 has a higher probability of following the scheduling command of the base station 22, and the terminal 2 having a small path loss for the base station 20 has a scheduling command of the base station 20. You are more likely to follow. As a result, the influence of the scheduling of other base stations on each base station is reduced and leveled, thereby preventing the noise rise of each base station from changing unstable.

I. 3-way handover

4B illustrates an example in which three base stations and a terminal in soft handover determine a selection probability for each base station. For the sake of brevity, only terminal 1 is shown in the drawings, and for convenience of description, both terminal 1 and terminal 2 are in soft handover state with base stations 20, 22, and 24, and base stations 20, 22, and 24 are shown. Assume that we are receiving scheduling commands from all of them.

As shown in Figure 4b, the path loss for the base station (20, 22, 24) of the terminal 1 is LA, 1, LB, 1, LC, 1, respectively, the base station (20, 22, 24) of the terminal 2 If the path loss for each field is LA, 2, LB, 2, LC2, respectively, the selection probability (PA, 1, PB, 1, PC1) of the base station 20, 22, 24 of the terminal 1 and the terminal 2 The selection probabilities PA, 2, PB, 2, and PC2 for the base stations 20, 22, and 24 may be defined as follows, respectively.

[Equation 10]

** Selection probability for base stations 20, 22, and 24 in handover with terminal 1 **

** Selection probability for base stations 20, 22, and 24 in handover with terminal 2 **

All. n-way handover

The equations (9) and (10) can be further extended and expressed as weight expressions for the n base stations and the terminal in soft handover.

Selection probabilities for n base stations in soft handover with terminals 1,2; , PN2) is expressed as follows.

[Equation 11]

** Selection probability for base stations in handover with terminal 1 **

** Selection probability for base stations in handover with terminal 2 **

Hereinafter, the base station scheduling method according to the fourth embodiment of the present invention will be described in detail with reference to the flowchart of FIG. 5. FIG. 5 illustrates a case in which all of the base stations in soft handover perform scheduling for the terminal when a certain terminal is in soft handover state with a plurality of base stations.

First, the base station controller determines an appropriate selection probability for each base station based on uplink-related information of base stations that are in soft handover with that terminal (S30) and then periodically (or changes in the selection probability) to the terminal. Whenever is required) (S31).

A base station in soft handover with an arbitrary terminal analyzes its noise rise, calculates the amount of noise rise that is currently acceptable, and determines the transmission power (or transmission rate) of the terminals that it should schedule based on this value. The scheduling is performed by (S32), (S33). That is, the base stations in soft handover with the terminal include the determined transmission power (or transmission rate) in the scheduling command and transmit them to the terminal.

The terminal receives the scheduling commands from the base stations in soft handover. The terminal applies a selection probability for each base station previously provided from the base station controller, randomly selects one scheduling command among the plurality of scheduling commands received, and follows the scheduling command (S34).

5. Fifth Embodiment of the Present Invention

Like the fourth embodiment, the fifth embodiment of the present invention is applicable to a case where the terminal receives a scheduling command from all base stations in soft handover.

According to the fifth embodiment of the present invention, the base station controller determines an appropriate selection probability for each base station based on the uplink-related information of the base stations in soft handover with the terminal, and then periodically (or changes in the selection probability) It is similar to the fourth embodiment in that it informs each time ".

However, when the base station controller informs the terminal of the selection probability for one base station (e.g., base station A), the base station controller also delivers the related selection probability with other base stations adjacent to base station A. N-1 probability of selection is delivered.)

For example, assuming that there are four base stations in handover with the terminal (eg, base station A, base station B, base station C, and base station D), the selection probability for base station A, which the terminal receives from the base station controller, Selection probability, selection probability for base station AC, and selection probability for base station AD.

When the selection probabilities for the base station A are transmitted from the base station controller, the terminal selects a maximum value or a minimum value among the selection probabilities. And in the same manner, selectivity of the remaining base stations (base station B, base station C, base station D) is also selected.

Then, when a scheduling command is received from each base station (base station A, base station B, base station C, base station D) being handed over, the terminal applies a selection probability (minimum value or maximum value) for each of the base stations given from the base station controller. . And randomly select and follow one scheduling command.

According to the fifth embodiment, the weight may be expressed by the following formula. (For convenience of description, only the formula for the terminal 1 will be shown.)

end. 2-way handover

[Equation 12]

Selection probability = {MIN ( ) or MAX ( )}

I. 3-way handover

[Equation 13]

Selection probability = {MIN ( ) or MAX ( )}

All. n-way handover

[Equation 14]

Selection probability = {MIN ( ) or MAX ( )}

As described above, the present invention is applied to uplink base station scheduling of a plurality of base stations and terminals in a soft handover state, thereby preventing performance degradation of uplink scheduling due to inconsistency in scheduling between the plurality of base stations and uplink at each base station. You can control the link noise rise more efficiently.

In addition, the present invention has been described with reference to the embodiments shown in the drawings, which are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. . Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1A illustrates an example of determining weights for two base stations and terminals in soft handover according to the present invention.

1B illustrates an example of determining weights for three base stations and a terminal in soft handover.

2 is a diagram illustrating a base station scheduling method according to a first embodiment of the present invention.

3 is a diagram illustrating a base station scheduling method according to a third embodiment of the present invention.

4A is a diagram illustrating an example in which two base stations and a terminal in soft handover determine a selection probability for each base station according to the fourth embodiment of the present invention.

4B illustrates an example in which three base stations and a terminal in soft handover determine a selection probability for each base station.

5 is a diagram illustrating a base station scheduling method according to a fourth embodiment of the present invention.

******* Description of the symbols for the main parts of the drawing ********

10, 12, 14, 20, 22, 24: base station (Node B)

Claims (23)

A wireless system for scheduling a terminal in which the base station is in soft handover state, Selecting, by the base station controller, a base station to be scheduled; Delivering weights for scheduling to the selected base station; And performing scheduling for each terminal in soft handover using the transferred weight. 2. The method of claim 1, further comprising determining, at the base station controller, a weight to be used for scheduling of each terminal. The method of claim 2, wherein the weight is The base station scheduling method is determined in consideration of the geopolitical relationship or the path loss between the terminal and the base station in soft handover. 4. The weighting factor of claim 3, wherein the greater the influence of the transmit power of the terminal in soft handover on the uplink noise rise of other base stations that are not scheduled for the terminal, the smaller the weight is to be applied to each terminal. And the smaller the larger the value is. The method of claim 3, wherein the base station A base station scheduling method characterized in that the transmission power and rate scheduling is performed based on its noise rise and the transmitted weight. The method of claim 2, wherein the weight is Determined by the following formula, Denotes a path loss between the base station (N) and the terminal (X), and the base station (A) is a scheduling base station. The method of claim 2, wherein the determining of the weight Selecting one base station in soft handover and calculating two-way handover weights of the selected base station and the scheduling base station; When all the weights are obtained by the calculation, the base station scheduling method comprising the step of determining one of them as the weight of the corresponding terminal. 8. The base station of claim 7, wherein the base station controller And among the weights obtained by the calculation, determine a maximum value as a weight of a corresponding terminal. 8. The base station of claim 7, wherein the base station controller The base station scheduling method of claim 1, wherein the minimum value of the weights obtained by the calculation is determined as the weight of the terminal. 8. The method of claim 7, wherein each two-way handover weight is Obtained by the following formula, Denotes a path loss between the base station (N) and the corresponding terminal (X) during the fast handover, and the base station (A) is a scheduling base station. A wireless system for scheduling a terminal in which the base station is in soft handover state, Selecting, by the base station controller, a base station to be scheduled; Delivering a scheduling limit value for scheduling to the selected base station; And performing scheduling for each terminal that is in soft handover so as not to exceed the delivered scheduling limit value. 12. The method of claim 11, further comprising the step of determining, by the base station controller, a scheduling limit value to be used for scheduling of each terminal. 13. The method of claim 12, wherein the scheduling limit is A base station scheduling method characterized in that the limit of the transmission power or transmission rate. 13. The method of claim 12, wherein the scheduling limit is The base station scheduling method is determined in consideration of the geopolitical relationship or the path loss between the terminal and the base station in soft handover. 15. The method of claim 14, wherein the greater the effect of the transmit power of the terminal in soft handover on the uplink noise rise of other base stations that are not scheduled for the terminal, the smaller the scheduling limit value to be applied to each terminal. The base station scheduling method characterized in that the smaller the larger value. A wireless system for scheduling a terminal in which the base stations are in soft handover state, Selecting, by the base station controller, a plurality of base stations for scheduling; Transmitting a selection probability of each selected base station to the terminal; And selecting one of the scheduling commands transmitted from the plurality of base stations by the terminal using the selected probability of each base station transmitted. 17. The method of claim 16, further comprising the step of determining a selection probability of each base station to be used by each terminal in the base station controller. 18. The method of claim 17, wherein the probability of selection is The base station scheduling method is determined in consideration of the geopolitical relationship or the path loss between the terminal and the base station in soft handover. 18. The method of claim 17, wherein the probability of selection is Obtained by the following formula, Denotes a path loss between the base station N and the terminal X, The base station scheduling method, characterized in that it means that the selection probability of the base station (N) to be used for the terminal (X). 18. The method of claim 17, wherein determining the selection probability Selecting one of the plurality of scheduling base stations, and calculating related selection probabilities of the selected base station and another scheduling base station; And if all selection probabilities are obtained by the calculation, determining all of the selection probabilities as the selection probabilities of the selected base station. 21. The method of claim 20, wherein when the determined selection probabilities are transmitted to the terminal, the terminal determines a maximum value of the transmitted selection probabilities as the selection probability of the corresponding base station. 21. The method of claim 20, wherein when the determined selection probabilities are transmitted to the terminal, the terminal determines a minimum value among the transmitted selection probabilities as the selection probability of the corresponding base station. 17. The method of claim 16, further comprising the step of transmitting a scheduling command by determining transmission power of a terminal to be scheduled according to noise rise in the base stations.