Abstract:
A controller in a wireless communication system for a mobile station simultaneously communicating with a plurality of base stations comprises a receiver receiving a plurality of signals, relating to a fist communication type, from a plurality of base stations, and receiving a signal, relating to a second communication type different from the first communication type, from a specific base station; and a transmitter, coupled to the receiver, transmitting a control signal generated on the basis of the signal relating to the second communication type received by the receiver from the specific base station, to the plurality of base stations and the specific base station.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a mobile communications system and a controller, and to a control method used therein.  
           [0002]    In a cellular mobile communications system, a mobile station for performing a communication including voice communication performs handover when moving between wireless zones (cells) corresponding to wireless base stations. During the handover procedure, the mobile station transmits radio signals to the plurality of wireless base stations involved in the handover. The wireless base stations involved in the handover transmit a user signal included in the radio signal received from the mobile station to a wireless base station controller, and the wireless base station controller combines the received user signal and transmits it to a core network via a mobile communication switching center.  
           [0003]    The wireless base station controller receives the signal from the core network via the mobile communication switching center, and transmits the received signal to the plurality of wireless base stations involved in the handover. The wireless base stations involved in the handover transmit the signal received from the wireless base station controller to the mobile station, which combines the signal received from the wireless base stations involved in the handover.  
           [0004]    Meanwhile, in cellular mobile communication systems, the adoption of a high-speed data communication methods specializing in data communication has been under research and development. For example, HSDPA (High Speed Downlink Packet Access) technologies on the W-CDMA (Wide band Code Division Multiple Access) mobile communication system, and EV-DO (Evolved High-speed Data Only) technologies on the CDMA 2000 system etc. correspond to the above high-speed data communication method. For example, 3Gpp TS 25.308 V5.3.0 etc. specifies HSDPA, and 3GPP2S.R0023 version 2.0 etc. specifies EV-DO.  
           [0005]    In Published Unexamined Japanese Patent Application No. 2001-217770, an outer loop transmit power control method for mobile stations during handover in a mobile communication system is disclosed. In this method, where the mobile station is communicating with the only one wireless base station, the wireless base station controls the transmit power of the mobile station based on the quality of the signal received from the mobile station. When the mobile station performs a handover, the control station combines the reception quality in the plurality of wireless base stations involved in the handover. The wireless base station controller controls the transmit power of the mobile station based on the combined reception quality.  
           [0006]    Even where the communication including voice communication and the high-speed data communication are performed at the same time, a quality of the cellular mobile communication is improved by performing outer loop control. However, until now, favorable results have not been achieved.  
         SUMMARY OF THE INVENTION  
         [0007]    It is therefore an object of the present invention to provide an improvement of wireless communication system. According to a first aspect of the present invention, a wireless communication system comprises a plurality of base stations simultaneously communicating with a mobile station by receiving a radio signal relating to a first communication type transmitted by the mobile station; a specific base station communicating with the mobile station by receiving a radio signal relating to a second communication type different from the first communication type; a controller receiving signals, based on the radio signal relating the first communication type, from the plurality of base stations, and receiving a signal based on the radio signal relating to the second communication type, from the specific base station, wherein said controller transmits a first control signal to the plurality of base stations and the specific base station, on the basis of the signal based on the radio signal relating to the second communication type received from the specific base station.  
           [0008]    According to a second aspect of the present invention; a controller in a wireless communication system for a mobile station simultaneously communicating with a plurality of base stations comprises a receiver receiving a plurality of signals, relating to a fist communication type, from a plurality of base stations, and receiving a signal, relating to a second communication type different from the first communication type, from a specific base station; and a transmitter, coupled to the receiver, transmitting a control signal generated on the basis of the signal relating to the second communication type received by the receiver from the specific base station, to the plurality of base stations and the specific base station. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, appended claims and accompanying drawings, wherein:  
         [0010]    [0010]FIG. 1 shows the structure of a mobile communication system;  
         [0011]    [0011]FIG. 2 shows the structure of a processor within a wireless base station controller;  
         [0012]    [0012]FIG. 3 shows the structure of an outer loop processor;  
         [0013]    [0013]FIG. 4 shows the operation of a mobile communication system;  
         [0014]    [0014]FIG. 5 shows the operation of the wireless base station controller;  
         [0015]    [0015]FIG. 6 shows the operation of a mobile communication system;  
         [0016]    [0016]FIG. 7 shows the operation of the wireless base station controller;  
         [0017]    [0017]FIG. 8 shows a signal format between a wireless base station and a wireless base station controller. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0018]    An embodiment of the present invention will be described-below with reference to the drawings. However, the present invention is not limited by the following description. Also, although specific details necessary for understanding the present invention are explained in the following description and drawings. In order not to obscure the explanation of the present invention, details unnecessary for understanding the present invention have been omitted.  
         [0019]    [0019]FIG. 1 shows the structure of the mobile communication system according to the embodiment of the present invention. The mobile communication system according to the embodiment of the present invention may be a CDMA (Code Division Multiple Access) mobile communication system, for example. The mobile communication system of the embodiment of the present invention comprises a mobile station  21 , wireless base stations  22 - 1  to  22 - n , a wireless base station controller  23 , a mobile communication switching device  24 , and a communication network  200 .  
         [0020]    The mobile communication system according to the embodiment of the present invention may perform a high-speed data communication specialized to data communication and a communication including voice communication at once. In the high-speed data communication specialized to data communication, several functions, e.g. soft handover, are not supported. Therefore, a mobile station performing high-speed data communication communicates with only one wireless base station at the same time. The communication including voice communication, in which a mobile station communicates with a plurality of base station at once during the handover procedure, is called a normal communication, in the following discussion, to be differentiated from the high-speed data communication.  
         [0021]    The mobile station  21  communicates with the communication network  200  via the wireless base stations  22 - 1  to  22 - n , wireless base station controller  23  and mobile communication switching center  24 . The mobile station  21  can perform the high-speed data communication and the normal communication at the same time. The high-speed data communication may be, for example, W-CDMA HSDPA or CDMA 2000 EV-DO. The mobile station  21  transmits and receives the radio signals comprising the user signal relating to the normal communication to and from the plurality of wireless base stations  22 - 1  to  22 - n  during the handover procedure. The mobile station  21 , however, transmits and receives the radio signal comprises the user signal relating to the high-speed data communication, to and from only one wireless base station among the wireless base stations  22 - 1  to  22 - n . Also, the mobile station  21  according to the embodiment of the present invention, controls the transmit power of radio signals to the wireless base stations  22 - 1  to  22 - n  based on a transmit power control signal included in the radio signal received from the wireless base stations  22 - 1  to  22 - n . The procedure to control the transmit power described in 3GPP TS 25.214 v5.3.0 may be applied to the embodiment of the present invention.  
         [0022]    The wireless base stations  22 - 1  to  22 - n  receive the user signal from the mobile station  21  as a radio signal, demodulate the radio signal received from the mobile station  21 , and derive quality information from the radio signal. The quality information according to the embodiment of the present invention is error information. The error information may show the error rate, CRC (cyclic redundancy code), etc. The error information here may be derived from a Viterbi decoder or Turbo decoder. The wireless base stations  22 - 1  to  22 - n  transmit the derived error information to the wireless base station controller  23  together with the user signal.  
         [0023]    Also, the wireless base stations  22 - 1  to  22 - n  receive, from the wireless base station controller  23 , the user signal and signal to interference ratio (SIR) target for the radio signal received by the wireless base stations  22 - 1  to  22 - n  from the mobile station  21 . SIR target is generated as a quality target by the wireless base station controller on the basis of the error information as explained in detail later. The wireless base stations  22 - 1  to  22 - n  generate a transmit power control signal-for controlling the transmit power of the radio signal transmitted by the mobile station  21 , on the basis of SIR target and calculated SIR of the radio signal received from the mobile station  21 . The procedure to generate the transmit power control signal described in 3GPP TS 25.214 v5.3.0 may be applied to the embodiment of the present invention.  
         [0024]    The transmit power control signal according to the embodiment of the present invention directs to increase or decrease the transmit power of the mobile station  21 . The transmit power control, however, may direct to control the transmit power to a certain value.  
         [0025]    The wireless base stations  22 - 1  to  22 - n  transmit the user signal and the transmit power control signal to the mobile station  21  as a radio signal.  
         [0026]    The wireless base station controller  23  receives the user signal and quality information thereof from the wireless base stations  22 - 1  to  22 - n , and transmits the received user signal to the communication network  200  via the mobile communication switching center  24 . The quality information according to the embodiment of the present invention is the error information as explained above.  
         [0027]    Also, during the handover procedure, the wireless base station controller  23  receives, via the wireless base stations involved in the handover among the wireless base stations  22 - 1  to  22 - n , the user signal transmitted from the mobile station  21 . In this case, the wireless base station controller  23  selectively combines the user signals received from the plurality of wireless base stations and transmits them to communication network  200  via the mobile communication switching center  24 .  
         [0028]    The wireless base station controller  23  receives the user signal from the communication network  200  via the mobile communication switching center, and transmits the received user signal to the base station among the wireless base stations  22 - 1  to  22 - n  communicating with the mobile station  21 . Also, during the handover procedure, the wireless base station controller  23  transmits the received-user signal to a plurality of wireless base stations among the wireless base stations  22 - 1  to  22 - n  involved in the handover procedure.  
         [0029]    The structure of the wireless base station controller will now be explained in detail. FIG. 2 is a block drawing showing the structure of a processor  1  included in the wireless base station controller  23 . The processor  1  is comprised of-circuit processors  11 - 1  to  11 - n , a combining processor  12 , a distributing processor  13 , an outer loop processor  14 , and a central processor  15 .  
         [0030]    The circuit processors  11 - 1  to  11 - n  respectively receive signals from the wireless base stations  22 - 1  to  22 - n  via a circuit  101 , and provide the signals received from each of the wireless base stations  22 - 1  to  22 - n  for the combining processor  12 .  
         [0031]    The signals communicated between the wireless base stations  22 - 1  to  22 - n  and the wireless base station controller  23 , as shown in FIG. 8, comprise a user signal Al and a control signal A 2 . The control signal A 2  is a control signal used between the wireless base stations  22 - 1  to  22 - n  and the wireless base station controller  23 . The control signal A 2  comprises the error information as quality information of the user signal Al received and demodulated by the wireless base station  22 - 1  to  22 - n.    
         [0032]    The circuit processors  11 - 1  to  11 - n  process the control signal A 2  included in each of the signals received from the wireless base stations  22 - 1  to  22 - n , and provide the processed control signals A 2  for the outer loop processor  14  as signals  111  to  11   n . Also, the circuit processors  11 - 1  to  11 - n  receive, from the distributing processor  13 , the user signals bound for the mobile station  21  and SIR target for the radio signal received by the wireless base stations  22 - 1  to  22 - n . The circuit processors  11 - 1  to  11 - n  transmit, to each of the wireless base stations  22 - 1  to  22 - n , the user signals bound for the mobile station  21  and the SIR targets as control signals.  
         [0033]    The combining processor  12  transmits the user signals received from the circuit processors  11 - 1  to  11 - n  to the mobile communication switching center  24  via the circuit  102 . During the handover procedure, the combining processor  12  selects and combines user signals that satisfy the quality requirement on the basis of the error information included in the control signals A 2  of the signals received from the circuit processors  11 - 1  to  11 - n . Satisfying the quality requirement may indicate that the error rate is less than a specific value, there is no error in terms of CRC, etc. The combining processor  12 , for example, selects one user signal, which satisfy the quality requirement based on the error information, for each frame from among the user signals received from the plurality of wireless base stations, and transmits the selected user signal to the communication network  200  via the mobile communication switching center  24 .  
         [0034]    In this case, the combining processor  12  transmits the combined user signal to the mobile communication switching center  24  via the circuit  102 , and, where the error information relating to all of the user signals received from the circuit processors  11 - 1  to  11 - n  does not satisfy the quality requirement, transmits the combined error information to the outer loop processor  14  as a signal  120 .  
         [0035]    The central processor  15  generally controls the mobile communication system. The central processor  15  controls whether the high-speed data communication is performed or not, and through which base station the high-speed data communication is performed. Also, the central processor provide a setting signal  130  to the outer loop controller  14  as explained in more detail later.  
         [0036]    [0036]FIG. 3 is a block diagram showing the structure of an outer loop processor  14 . The outer loop processor  14  is comprised of a selector  141  and a control signal generator  142 . In the outer loop processor  14 , the signals  111  to  11   n  from the circuit processors  11 - 1  to  11 - n  and the control signal  120  from the combining processor  12  are input to the selector  141 .  
         [0037]    The selector  141  selects one from among the signals  111  to  11   n  and the signal  120  based on a setting signal  130  from a central processor  15 , and provides the selected one for the control signal generator  142 . The setting signal  130  from the central processor  15  will be explained in more detail later.  
         [0038]    The control signal generator  142  generates SIR target as the quality target for the radio signal received by the wireless base stations  22 - 1  to  22 - n  on the basis of the control  111  to  11   n  and the signal  120  input from the selector  141 , and then outputs the generated SIR target to the distributing processor  13 .  
         [0039]    Referring to FIG. 2 again, the distributing processor  13  receives, from the mobile communication switching center  24  via the circuit  102 , the user signal bound for the mobile station  21 , and distributes the received user signal to the circuit processors  11 - 1  to  11 - n . Also, the distributing processor  13  distributes SIR target received from the outer loop processor  14  to the circuit processors  11 - 1  to  11 - n.    
         [0040]    [0040]FIG. 4 shows the operation procedure of the mobile communication system according to the embodiment of the present invention. Referring to FIGS.  1  to  5  and  8 , the operation of a CDMA mobile communication system according to the embodiment of the present invention will be explained. The mobile station  21  communicates with the network  200  via the wireless base stations  22 - 1  to  22 - n , wireless base station controller  23 , and the mobile communication switching center  24 . Also, the mobile station  21  performs a handover via the wireless base stations  22 - 1 ,  22 - 2  and  22 - 3 .  
         [0041]    The mobile station  21  transmits a radio signal to the wireless base station  22 - 1  to  22 - 3  (S 11 ). The wireless base stations  22 - 1  to  22 - 3  each receive a user signal from the mobile station  21  as a radio signal (S 12 ), and demodulate the radio signals received from the mobile station  21  to derive the user signal and the error information of the user signals from the radio signal received (S 13 ). Also, the wireless base stations  22 - 1  to  22 - 3  calculate SIR of the radio signal received from the mobile station  21  in order to generate a transmit power control signal for an uplink transmit power control(S 14 ). The wireless base stations  22 - 1  to  22 - 3  then transmit the received user signals A 1  and a control signals A 2  including the error information to the wireless base station controller  23  (S 15 ).  
         [0042]    [0042]FIG. 5 shows the operation of the wireless base station controller (S 16 ) in detail. The circuit processors  11 - 1  to  11 - 3  in the wireless base station controller  23  receive the signals from each of the wireless base stations  22 - 1  to  22 - 3  (S 161 ). Also, the circuit processor  11 - 1  to  11 - 3  provide, the received signals for the combining processor  12 , and provide the control signals A 2  included in the received signals as signals  111  to  113  for the outer loop processor  14  (S 162 ).  
         [0043]    The combining processor  12  selects and combines the user signals that satisfy the quality requirement based on the error information included in the control signal A 2  of the signal received from the circuit processors  11 - 1  to  11 - 3  (S 163 ). In this case, the combining processor  12  transmits the combined user signals to the mobile communication switching center  24  via the circuit  102  (S 164 ). Also, the combining processor  12 , where all of the error information received from the circuit processors  11 - 1  to  11 - 3  does not satisfy the quality requirement, combines the error information and provides the combined error information as the signal  120  for the outer loop processor  14  (S 165 ).  
         [0044]    The selector  141  of the outer loop processor  14  receives the signals  111  to  113  from the circuit processors  11 - 1  to  11 - 3 , and also receives the signal  120  from the combining processor  12 . The selector  141  selects one from among the control signals  111  to  113  and the control signal  120  based on a setting signal  130  from the central processor  15  within the wireless base station controller  23 , and provides it for the control signal generator  142 .  
         [0045]    Where the mobile station  21  does not perform the high-speed data communication, the central processor  15  provides, for the selector  141  in the outer loop processor  14 , the setting signal  130  indicating that the selector  141  selects the control signal  120  and provides it for the control signal generator  142  (S 166 ). This control will hereafter be referred to as control procedure  1 . In this case, the control signal generator  142 , when the control signal  120  has been provided from the selector  141 , generates SIR target, and provide the generated SIR target for the distributing processor  13  (S 168 ). The distributing processor  13  distributes SIR target received from the control signal generator  142 , together with the user signal received from the mobile communication switching center  24  via the circuit  102 , to the circuit processors  11 - 1  to  11 - 3  (S 1610 ). The circuit processors  11 - 1  to  11 - 3  respectively transmit the received user signal and SIR target to the wireless base stations  22 - 1  to  22 - 3  (S 1611 ).  
         [0046]    Referring to FIG. 4 again, the wireless base stations  22 - 1  to  22 - 3  receives the user signal and SIR target from the wireless base station controller  23 , then SIR targets of the wireless base stations  22 - 1  to  22 - 3  are updated (S 17 ). The wireless base stations  22 - 1  to  22 - 3  generate the transmit power control signal for controlling the transmit power of the radio signal transmitted by the mobile station  21  based on the updated SIR target and the calculated SIR in the step S 14  (S 18 ). Also, the wireless base stations  22 - 1  to  22 - 3  transmit the user signal and the transmit power control signals generated to the mobile station  21  (S 19 ).  
         [0047]    The mobile station  21  receives the user signals and the transmit power control signals from the wireless base stations  22 - 1  to  22 - 3  (S 20 ). Also, the mobile station  21  controls the transmit power of the radio signal to the wireless base stations  22 - 1  to  22 - 3  on the basis of the transmit power control signals received (S 21 ).  
         [0048]    In this way, where the mobile station  21  does not perform the high-speed data communication, SIR targets are updated only when the error rate information relating to all of the user signals received by the wireless base stations  22 - 1  to  22 - 3  does not satisfy the quality requirement. However, as described below, where the mobile station  21  performs the normal communication and the high-speed data communication at the same time, the SIR targets must be updated by a different procedure.  
         [0049]    As described above, the mobile station  21  transmits and receives radio signals relating to the high-speed data communication to and from only one wireless base station among the wireless base stations  22 - 1  to  22 - n . Here, the mobile station  21  performs transmission and reception of signals relating to the high-speed data communication with the wireless base station  22 - 2 , i.e. it transmits and receives user signals relating to the high-speed data communication only with respect to the wireless base station  22 - 2 . Consequently, if the control procedure  1  is executed, while the high-speed data communication is performed together with the normal communication, the quality information of a user signal relating to the high-speed data communication received by the wireless base station  22 - 2  would continuously be unsatisfied with the quality requirement, and then the high-speed data communication would be degraded. For example, in a case where the error information on the user signal relating to the normal communication received by the wireless base station  22 - 1  satisfies the quality requirement, the SIR targets in the wireless base stations  22 - 1  to  22 - 3  are not updated even though the error information on the signal relating to the high-speed data communication received by the wireless base station  22 - 2  does not satisfy the quality requirement. Consequently, the error information of a user signal relating to the high-speed data communication received by the wireless base station  22 - 2  would continuously be unsatisfied with the quality requirement, and then the high-speed data communication would be degraded.  
         [0050]    Thus, where the mobile station  21  is performing the high-speed data communication, control procedure  2  described bellow is executed. In the control procedure  2 , the steps from S 11  to S 165  are the same as those in the control procedure  1 . Referring to FIG. 5 again, during the control procedure  2 , the central processor  15  detects the high-speed data communication being performed with the base station  22 - 2 . The central processor provides, for the selector  141 , the setting signal  130  directing to select a signal  112 , which is relevant to the user signal relating to the high-speed communication, from among the signals  111  to  113 (S 167 ). Here, because the central processor  15  controls whether the high-speed data communication is performed between the mobile station  21  and any one of the wireless base stations, the central processor  15  can detect which one among the signal  111  to  113  is relevant to the user signal relating to the high-speed data communication. The selector  114  provides the signal  112  for the control signal generator  142  on the basis of the setting signal  130  from the central processor. The control signal generator  142  generates, based on the input signal  112 , a SIR target for the radio signal, transmitted by the mobile station  21 , received by the wireless base station  22 - 1  to  22 - 3 . Then, the control signal generator  142  provides the generated SIR target for the distributing processor  13  (S 169 ). The distributing processor  13  distributes SIR target received from the control signal generator  142 , together with the user signal received from the mobile communication switching center  24  via the circuit  102 , to the circuit processors  11 - 1  to  11 - 3  (S 1610 ). The circuit processors  11 - 1  to  11 - 3  respectively transmit the received user signal and SIR target to the wireless base stations  22 - 1  to  22 - 3  (S 1611 ).  
         [0051]    Referring to FIG. 4 again, the wireless base stations  22 - 1  to  22 - 3  receives the user signal and SIR target from the wireless base station controller  23 , then SIR targets of the wireless base stations  22 - 1  to  22 - 3  are updated (S 17 ). The wireless base stations  22 - 1  to  22 - 3  generate the transmit power control signal for controlling the transmit power of the radio signal transmitted by the mobile station  21  based on the updated SIR target and the calculated SIR in S 14  (S 18 ). Also, the wireless base stations  22 - 1  to  22 - 3  transmit the user signal and the transmit power control signals generated to the mobile station  21  (Sl 9 ).  
         [0052]    The mobile station  21  receives the user signals and the transmit power control signals from the wireless base stations  22 - 1  to  22 - 3  (S 20 ). Also, the mobile station  21  controls the transmit power of the radio signal to the wireless base stations  22 - 1  to  22 - 3  on the basis of the transmit power control signals received (S 21 ).  
         [0053]    By executing the above control procedure  2 , in cases where the mobile station  21  performs the high-speed data communication, the error information of a user signal relating to the high-speed data communication is no longer continuously unsatisfied with the quality requirement. Then, the quality of the high-speed data communication is improved. As described above, a case where the mobile station  21  performs transmission and reception of signals relating to the high-speed data communication with the wireless base station  22 - 2  is considered. In this case, even when, for example, the error information relevant to a user signal relating to the normal communication received by the wireless base station  22 - 1  satisfies the quality requirement, if the error rate information relevant to a signal relating to the high-speed data communication received by the wireless base station  22 - 2  does not satisfy the quality requirement, the SIR targets in the wireless base stations  22 - 1  to  22 - 3  are updated. Based on the updated SIR targets, the wireless base stations  22 - 1  to  22 - 3  control the transmit power of the mobile station  21 . Consequently, there is no continuation of the state where the error information of the user signals relating to the high-speed data communication received by the wireless base station  22 - 2  does not satisfy the quality requirement.  
         [0054]    The procedure to control the transmit power of the radio signal transmitted by the mobile station  21  is explained in detail bellow. The wireless base stations  22 - 1  to  22 - 3 , where SIR calculated based on a signal received from the mobile station  21  falls below SIR target, transmit a signal requesting an increase in transmit power or a signal indicating a specific transmit power to the mobile station  21 . Also, the wireless base stations  22 - 1  to  22 - 3 , where the SRI calculated based on a signal received from the mobile station  21  rises above SIR target, transmit a signal requesting a decrease in transmit power or a signal indicating a specific transmit power to the mobile station  21 .  
         [0055]    The mobile station  21  controls transmit power based on the transmit power control signals received from the wireless base stations  22 - 1  to  22 - 3 . At this time, the mobile station  21 , according to-a specific rule, controls the transmit power based on the plurality of transmit power control signals received from the wireless base stations  22 - 1  to  22 - 3 . The specific rule may be, for example, the following. Where all of the received transmit power control signals indicate an increase in transmit power, the mobile station  21  increases the transmit power by a specific percentage. Where any one of the received transmit power control signals indicates a decrease in transmit power, the mobile station  21  decreases the transmit power by a specific percentage. Also, the mobile station  21  may regard a plurality of transmit power control signals received during a handover procedure as the same. In that case, the mobile station  21  combines the received plurality of transmit power control signals into one. The mobile station  21 , when the combined transmit power control signal indicates an increase in transmit power, increases the transmit power by a specific percentage, and when the combined transmit power control signal indicates a decrease in transmit power, decreases the transmit power by a specific percentage. Also, the mobile station  21  may give the transmit power control signal from the wireless base station performing the high-speed data communication a priority. In this case, for example, the mobile station  21  controls the transmit power on the basis of the transmit power control signal from the wireless base station performing the high-speed data communication.  
         [0056]    The procedure to control the transmit power described in 3GPP TS 25.214 v5.3.0 may also be applied to the embodiment of the present invention.  
         [0057]    In this embodiment, when the high-speed data communication is performed, the SIR target is generated based on the only one signal among the signals  111  to  1   n  from the circuit processors  11 - 1  to  11 - n  since only one wireless base station performs the high-speed data communication. The number of the signals among the  111  to  11   n , based on which the SIR target is generated, is not limited to the only one. When a plurality of wireless base stations, the number of which is less than the number of the wireless base stations involved in the handover on the normal communication, perform the high-speed data communication, the SIR target may be generated based on the plurality of signals among  111  to  11   n  relating to the high-speed data communication.  
         [0058]    Referring to FIGS. 6 and 7, other embodiments of the present invention will be explained. The same operations as those in the previous embodiment are referred to as the same number.  
         [0059]    In the mobile communication system according to the previous embodiment of the present invention, the outer loop processor  14  in the wireless base station controller  23  generates and provides for the distributing processor  13 , SIR target for the radio signal received by the wireless base stations  22 - 1  to  22 - 3  in order to control the transmit power of the mobile station  21 . Referring to FIG. 7, in this embodiment, the outer loop processor  14  in the wireless base station controller  23 , however, may generate and provides, for the distributing processor  13 , other control signal  40  than the SIR target (S 301 , S 302 ). The control signal  40  may be other quality target (e.g. error rate target, Eb/N 0  target ( where Eb is the energy, or power density, per user bit and N 0  is the interference and noise power density), etc.), directing to change modulation type (e.g. BPSK, QPSK, 16QAM, etc.), transmit power, communication type (e.g. the high-speed data communication to the normal communication), and bit rate (spreading factor) of the radio signal or the user signal transmitted by the mobile station 21 , etc.  
         [0060]    The distributing processor  13  distributes, to the circuit processors  11 - 1  to  11 - 3 , the control signal  40  received from the outer loop processor  14 , together with the user signal received from the mobile communication switching center  24  via the circuit  102  (S 303 ). The circuit processors  11 - 1  to  11 - 3  respectively transmit the received user signal and the control signal  40  to the wireless base stations  22 - 1  to  22 - 3  (S 304 ).  
         [0061]    Referring to FIG. 6, the wireless base stations  22 - 1  to  22 - 3  receive the user signal and the control signal  40  from the wireless base station controller  23  (S 31 ). In the mobile communication system according to the previous embodiment of the present invention, the wireless base stations  22 - 1  to  22 - 3  generate the transmit power control signal for controlling the transmit power of the radio signal transmitted by the mobile station  21 . In this embodiment, the wireless base station  22 - 1  to  22 - 3 , however, may generate other control signal  50  than the transmit power control signal based on the control signal  40  received from the wireless base station controller  23  (S 32 ). The control signal  50  may be directing to change modulation type (e.g. BPSK, QPSK, 16QAM, etc.), transmit power, bit rate (spreading factor), and communication type (e.g. the high speed data communication to the normal communication), of the radio signal or the user signal transmitted by the mobile station  21 , etc. Also, the wireless base stations  22 - 1  to  22 - 3  transmit the user signal and the control signals  50  generated to the mobile station  21  (S 33 ).  
         [0062]    The mobile station  21  receives the user signals and the control signals  50  from the wireless base stations  22 - 1  to  22 - 3  (S 34 ). In the mobile communication system according to the previous embodiment of the present invention, the mobile station  21  controls the transmit power of the radio signal to the wireless base stations  22 - 1  to  22 - 3  on the basis of the transmit power control signals received. In this embodiment, the mobile station  21 , however, may control the radio signal in other ways than controlling the transmit power of the radio signal (S 35 ). The mobile station  21  may change modulation type (e.g. BPSK, QPSK, 16QAM, etc.), transmit power, bit rate (spreading factor), and communication type (e.g. the high speed data communication to the normal communication), of the radio signal or the user signal transmitted, etc.  
         [0063]    In this embodiment, when the high-speed data communication is performed, the control signal  40  is generated based on the only one signal among the signals  111  to  11   n  from the circuit processors  11 - 1  to  11 - n  since only one wireless base station performs the high-speed data communication. The number of the signals among the  111  to  11   n , based on which the control signal  40  is generated, is not limited to the only one. When a plurality of wireless base stations, the number of which is less than the number of the wireless base stations involved in the handover on the normal communication, perform the high-speed data communication, the control signal  40  may be generated based on the plurality of signals among  111  to  11   n  relating to the high-speed data communication.  
         [0064]    In the embodiments of the present invention described above, the setting signal  130  is input from a central processor  15  inside the wireless base station controller  23  to the outer loop processor  14 . The setting signal  130 , however, may also be input from outside the wireless base station controller  23 .  
         [0065]    In the embodiments described above, the user signal relating to the normal communication may be Dedicated physical control channel (DPCCH) in the WCDMA. Also, the uplink user signal relating to the high-speed data communication may be High-speed dedicated physical control channel (HS-DPCCH), and the downlink user signal may be DPCCH and High-speed shared control channel (HS-SCCH) in the WCDMA.  
         [0066]    A characteristic aspect of the present invention is that, when the mobile station transmits radio signals to a plurality of base stations, those base stations are controlled based on the radio signal received by a specific base station of them, regardless of whether the high-speed data communication is performed or not. According to one embodiment of the present invention, a control signal for controlling the base stations is determined based on quality information on the radio signal received by a specific base station.  
         [0067]    Also a characteristic aspect of the present invention is that, when the mobile station transmits radio signals to a plurality of base stations, those base stations are controlled in different way depending on whether high-speed communication is performed or not. According to one embodiment of the present invention, the base stations are controlled based on the radio signal related to the high-speed data communication.  
         [0068]    According to the present invention, cellular mobile communication system can be improved. Also, maintenance of the enough power required for signals relating to the high-speed data communication transmitted by a mobile station is possible and the transfer efficiency of the high-speed data communication can be improved. Further, setting the power relating to the high-speed data communication transmitted by a mobile station higher than that for the normal communication is unnecessary. Consequently, the amount of signal interference can be suppressed, and communication capacity can be improved.  
         [0069]    It will be obvious to those having skill in the art that many changes may be made in the above-described details of the preferred embodiments of the present invention. The scope of the present invention should be determined by the following claims.