JP2007300681A - Mobile communication system, radio station suitable for use therein, mobile station, and downlink transmission power control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile communication system capable of reducing control information transmitted from a mobile station to a radio station, reducing uplink radio resource traffic, and suppressing the amount of interference to the entire mobile communication system, and suitable for this use A radio station, a mobile station, and a downlink transmission power control method are provided. In a mobile communication system in which the same information is transmitted from a base station 30a to a plurality of mobile stations (40a to 40c) with a predetermined downlink transmission power. The station 30a includes transmission power control means for controlling predetermined downlink transmission power based on control information transmitted by a part of a plurality of mobile stations (40a to 40c) located under the base station 30a.
[Selection] Figure 1

Description

  The present invention relates to a mobile communication system in which the same information is transmitted from a radio station to a plurality of mobile stations, a radio station suitable for use in this, a mobile station, and a downlink transmission power control method.

  Conventionally, techniques for simultaneously transmitting the same information from a radio station such as a base station or a radio control apparatus to a plurality of mobile stations include techniques such as broadcast and multicast.

  As shown in FIG. 8, broadcast is a technology in which one or a plurality of base stations (11 to 17) transmit the same information to all mobile stations (101 to 112) located in the area at the same time. (For example, Non-Patent Document 1) Multicast refers to a specific group of mobile stations (101, 103, 105) in which one or a plurality of base stations (11 to 17) are located in the area, as shown in FIG. , 106, 108, 109, 110), which transmits the same information all at once (for example, Non-Patent Document 2).

Further, in the conventional mobile communication system, when the same information is transmitted from a radio station to a plurality of mobile stations with a predetermined downlink transmission power, as a technique for the radio station to control the predetermined downlink transmission power, a mobile station Based on the received quality (received power, ratio of received power and interference power (SIR) of the same information, error bit rate of the same information, etc.) (For example, Patent Document 1)
Japanese Patent Laid-Open No. 2001-292096 3rd Generation Partnership Project Technical Specification Group Terminals, 23.041 Technical realization of Cell Broadcast Service (CBS), October 2000 3rd Generation Partnership Project Technical Specification Group Radio Access Network, 25.324 Broadcast / Multicast Control BMC, December 2000

  However, in a conventional mobile communication system, when a radio station such as a base station or a radio network controller controls a predetermined downlink transmission power, the radio station positions transmission of control information (reception quality, etc.) under control. To all mobile stations. Accordingly, since the mobile station is located near the radio station, the mobile station transmits control information to the radio station even when there is no need to control predetermined downlink transmission power. For this reason, there is a problem that control information that does not contribute to control of predetermined downlink transmission power increases, and traffic of uplink radio resources increases.

  Accordingly, the present invention has been made in view of the above points, and can reduce control information transmitted from a mobile station to a radio station, reduce traffic of uplink radio resources, and an amount of interference with the entire mobile communication system. It is an object of the present invention to provide a mobile communication system that can suppress the transmission, a radio station suitable for use in the communication system, a mobile station, and a downlink transmission power control method.

  A first feature of the present invention is that, in a mobile communication system in which the same information is transmitted from a radio station to a plurality of mobile stations with a predetermined downlink transmission power, the radio station is a mobile station located under the radio station. The gist of the present invention is to provide transmission power control means for controlling predetermined downlink transmission power based on the control information transmitted by the unit.

  According to such a feature, since the wireless station controls a predetermined downlink transmission power based on control information transmitted by a part of a plurality of mobile stations located under the wireless station, the wireless station is located under the wireless station. Compared to the case where control information is transmitted by all mobile stations, the control information transmitted from the mobile station to the radio station can be reduced, the traffic of uplink radio resources can be reduced, and the amount of interference to the entire mobile communication system can be reduced. be able to.

  According to a second aspect of the present invention, in a mobile communication system in which the same information is transmitted from a wireless station to a plurality of mobile stations with a predetermined downlink transmission power, the wireless station is configured to perform predetermined processing based on control information transmitted by the mobile station. Transmission power control means for controlling the downlink transmission power of the mobile station, the mobile station transmitted by the wireless station based on the determination means for determining whether or not to transmit control information to the wireless station, and the determination result by the determination means The gist of the present invention is that it comprises transmission means for transmitting control information generated by the reception quality of the same information to a radio station.

  According to such a feature, since the control information is transmitted to the radio station only when the mobile station determines to transmit the control information to the radio station, the control information transmitted from the mobile station to the radio station can be reduced. Uplink resource traffic can be reduced, and the amount of interference with the entire mobile communication system can be suppressed.

  According to a third aspect of the present invention, in a mobile communication system in which the same information is transmitted from a radio station to a plurality of mobile stations with a predetermined downlink transmission power, a threshold at which the radio station sets a threshold for reception quality Based on the setting information, the transmission means for transmitting the same information as the threshold of the reception quality set by the threshold setting means to the mobile station, and the predetermined downlink transmission power based on the control information transmitted by the mobile station Transmission power control means for controlling, the mobile station calculates reception quality calculation means for calculating the reception quality of the same information transmitted by the radio station, and the reception quality calculated by the reception quality calculation means and transmitted by the radio station A determination means for comparing whether or not to transmit control information to the radio station, and a transmission means for transmitting control information to the radio station based on a determination result by the determination means To have The gist.

  According to this feature, when the reception quality of the same information calculated by the mobile station exceeds the reception quality threshold, control information is not transmitted to the radio station, which contributes to control of predetermined downlink transmission power. Control information not to be transmitted can be reduced, traffic of radio uplink resources can be reduced, and the amount of interference with the entire mobile communication system can be suppressed.

  According to a fourth aspect of the present invention, in a mobile communication system in which the same information is transmitted from a wireless station to a plurality of mobile stations with a predetermined downlink transmission power, the wireless station transmits a control information transmission request to which mobile station. Based on the control information transmitted by the mobile station selected by the mobile station selection means, the transmission request transmission means for transmitting a transmission request to the mobile station selected by the mobile station selection means, and the mobile station selected by the mobile station selection means, A transmission power control means for controlling a predetermined downlink transmission power, and a mobile station comprising a transmission means for transmitting control information to the wireless station based on a transmission request transmitted by the wireless station. To do.

  According to this feature, since predetermined downlink transmission power is controlled based only on control information transmitted by the mobile station selected by the radio station, control information transmitted from the mobile station to the radio station can be reduced. Thus, traffic of radio uplink resources can be reduced, and the amount of interference with the entire mobile communication system can be suppressed.

  According to a fifth feature of the present invention, in the first to fourth features of the present invention, the transmission power control means selects control information selected from a plurality of control information transmitted by the mobile station on a predetermined basis. Based on the above, the gist is to control predetermined downlink transmission power.

  A sixth feature of the present invention is the control according to any one of the first to fourth features of the present invention, wherein the transmission power control means instructs all control information transmitted by the mobile station to lower a predetermined downlink transmission power. In the case of information, the gist is to reduce a predetermined downlink transmission power.

  A seventh feature of the present invention is that, in the first to fourth features of the present invention, the transmission power control means increases a predetermined downlink transmission power among a plurality of control information transmitted by the mobile station. The gist is to increase the predetermined downlink transmission power when one or more control information to be instructed is included.

  An eighth feature of the present invention is that, in the first to fourth features of the present invention, the transmission power control means increases a predetermined downlink transmission power among a plurality of control information transmitted from the mobile station. The gist is to count how many control information to instruct or control information to instruct to lower the predetermined downlink transmission power, and control the predetermined downlink transmission power based on the count result.

  A ninth feature of the present invention is that a downlink transmission power control method for controlling a predetermined downlink transmission power when the same information is transmitted from a radio station to a plurality of mobile stations with a predetermined downlink transmission power Step A in which the mobile station determines whether or not to transmit information to the radio station, and the mobile station transmits control information generated based on the reception quality of the same information transmitted by the radio station based on the determination result in Step A. And a step C in which the radio station controls a predetermined downlink transmission power based on the control information transmitted by the mobile station.

  A tenth feature of the present invention is that a downlink transmission power control method for controlling a predetermined downlink transmission power when the same information is transmitted from a radio station to a plurality of mobile stations with a predetermined downlink transmission power Step D in which the wireless station sets the quality threshold value, Step E in which the wireless station transmits the same information as the reception quality threshold value set in Step D to the mobile station, and the wireless station Step F in which the mobile station calculates the reception quality of the same information, and the mobile station compares the reception quality calculated in step F with the threshold value of the reception quality transmitted by the radio station, Step G for determining whether to transmit to the mobile station, Step H for transmitting the control information to the radio station based on the determination result in Step G, and predetermined downlink transmission based on the control information transmitted by the mobile station Electric And summarized in that the steps I of the radio station controls a is provided.

  An eleventh feature of the present invention is that a downlink transmission power control method for controlling a predetermined downlink transmission power when the same information is transmitted from a radio station to a plurality of mobile stations with a predetermined downlink transmission power. Step J for selecting whether the radio station transmits a control information transmission request to the mobile station, Step K for the radio station to transmit a transmission request to the mobile station selected in Step J, and a transmission request transmitted by the radio station And a step L in which the mobile station transmits control information to the radio station, and a step M in which the radio station controls a predetermined downlink transmission power based on the control information transmitted by the mobile station. And

  A twelfth feature of the present invention is that whether a mobile station that receives the same information transmitted from a radio station with a predetermined downlink transmission power transmits control information for controlling the predetermined downlink transmission power to the radio station. Based on the determination result of the determination means, reception quality calculation means for calculating the reception quality of the same information transmitted by the wireless station, and control generated based on the reception quality calculated by the reception quality calculation means The gist of the present invention is that it comprises a transmission means for transmitting information to a radio station.

  A thirteenth feature of the present invention is that a mobile station that receives the same information transmitted from a radio station with a predetermined downlink transmission power calculates reception quality calculation means for calculating the reception quality of the same information transmitted by the radio station; A determination means for comparing the reception quality calculated by the reception quality calculation means with a threshold value of the reception quality transmitted by the radio station to determine whether or not to transmit control information to the radio station, and a determination result by the determination means And transmitting means for transmitting the control information to the radio station.

  A fourteenth feature of the present invention is a mobile station selection means for selecting to which mobile station a radio station that transmits the same information to a plurality of mobile stations with a predetermined downlink transmission power transmits a control information transmission request; The gist of the invention is that it comprises transmission power control means for controlling predetermined downlink transmission power based on control information transmitted by the mobile station selected by the mobile station selection means.

  According to the mobile communication system, the radio station suitable for this, the mobile station, and the downlink transmission power control method according to the present invention, the radio station is controlled from a part of a plurality of mobile stations located under the radio station. Since the information is received, control information transmitted from the mobile station to the radio station can be reduced, traffic of uplink radio resources can be reduced, and the amount of interference with the entire mobile communication system can be suppressed.

(Configuration of mobile communication system in the present embodiment)
Hereinafter, the configuration of the mobile communication system in the present embodiment will be described with reference to the drawings. FIG. 1 is a diagram showing an overall configuration of a mobile communication system in the present embodiment. As shown in FIG. 1, the mobile communication system in the present embodiment includes a radio network controller 20, a plurality of base stations (30a to 30d), and a plurality of mobile stations (40a to 40j).

  The radio network controller 20 transmits the same information to a plurality of mobile stations (40a to 40j) via a plurality of base stations (30a to 30d) (for example, multicast communication and broadband communication). In the present embodiment, the radio network controller 20 and the base stations (30a to 30d) are specific examples of radio stations.

  In addition, since the functions of the base stations (30a to 30d) are the same and the functions of the mobile stations (40a to 40j) are also the same, in the following description, the base station 30a and the mobile station 40a will be described as an example. . Note that the radio network controller 20 may have the function of the base station 30a.

  FIG. 2 is a block diagram showing configurations of the base station 30a and the mobile station 40a suitable for use in the mobile communication system according to the present embodiment. As shown in FIG. 2, the base station 30 a includes a transmission / reception unit 31 and a transmission power control unit 32.

  The transmission / reception unit 31 transmits the same information to the mobile station 40a with a predetermined downlink transmission power, and receives the control information transmitted by the mobile station 40a. The transmission power control unit 32 is transmission power control means for controlling predetermined downlink transmission power based on the control information transmitted by the mobile station 40a.

  Specifically, the transmission power control unit 32 controls predetermined downlink transmission power based on control information selected based on a predetermined reference from a plurality of control information transmitted by a plurality of mobile stations. Here, the control information selected on the basis of the predetermined criterion is, for example, control information instructing to control the predetermined downlink transmission power to the largest downlink transmission power, or the predetermined downlink transmission power second. This is control information for instructing control to a large downlink transmission power.

  For example, the control information transmitted by a plurality of mobile stations instructs to increase the predetermined downlink transmission power by “control information a” for instructing to increase by 10 dBm, “control information b” for instructing to increase by 5 dBm, and to increase by 3 dBm. In the case of “control information c”, the transmission power control unit 32 controls the predetermined downlink transmission power based on the control information instructing to control the predetermined downlink transmission power to the largest downlink transmission power. The transmission power control unit 32 controls a predetermined downlink transmission power based on the first largest “control information a”. When the transmission power control unit 32 controls the predetermined downlink transmission power based on the control information instructing to control the predetermined downlink transmission power to the second largest downlink transmission power, the transmission power control unit 32 controls a predetermined downlink transmission power based on the second largest “control information b”.

  Further, the transmission power control unit 32 reduces the predetermined downlink transmission power when all the control information transmitted by the plurality of mobile stations is control information instructing to decrease the predetermined downlink transmission power. You may control to.

  For example, control information transmitted by a plurality of mobile stations instructs “control information d” for instructing to lower the predetermined downlink transmission power by 10 dBm, “control information e” for instructing to lower by 5 dBm, and “to reduce by 3 dBm” In the case of “control information f”, the transmission power control unit 32 reduces the downlink transmission power by a predetermined power (1 dBm, 3 dBm, etc.).

  Further, the transmission power control unit 32, when the plurality of control information transmitted by the plurality of mobile stations includes one or more control information instructing to increase the predetermined downlink transmission power, You may control to raise downlink transmission power.

  For example, a plurality of pieces of control information transmitted by a plurality of mobile stations increase “control information g” instructing to decrease a predetermined downlink transmission power by 10 dBm, “control information h” instructing to decrease by 5 dBm, and increase by 3 dBm. In the case of “control information i” to instruct, the transmission power control unit 32 increases the downlink transmission power by a predetermined power (1 dBm, 3 dBm, etc.).

  In addition, the transmission power control unit 32 decreases the control information instructing to increase the predetermined downlink transmission power among the plurality of control information transmitted by the plurality of mobile stations, or the predetermined downlink transmission power. It may be counted how many pieces of control information instructing are included, and a predetermined downlink transmission power may be controlled based on the count result.

  For example, when three or more pieces of control information instructing to increase a predetermined downlink transmission power are included in control information transmitted by a plurality of mobile stations, the transmission power control unit 32 sets the downlink transmission power. When two or more pieces of control information instructing to increase the predetermined power (1 dBm, 3 dBm, etc.) and decrease the predetermined downlink transmission power are included, the downlink transmission power is decreased by the predetermined power (1 dBm, 3 dBm, etc.) .

  The mobile station 40 a includes a transmission / reception unit 41, a determination unit 42, a reception quality calculation unit 43, and a control information generation unit 44.

  The transmission / reception unit 41 receives the same information transmitted by the mobile station 40a, and transmits control information to the base station 30a.

  The determination unit 42 is a determination unit that determines whether or not to transmit control information to the base station 30a. Specifically, the determination unit 42 transmits the control information to the base station 30a at a predetermined frequency (once every two times, once every three times, etc.) for a plurality of identical information received by the transmission / reception unit 41. to decide. Further, the determination unit 42 may randomly determine whether or not to transmit the control information to the base station 30a.

  The reception quality calculation unit 43 is a reception quality calculation unit that calculates the reception quality of the same information received by the transmission / reception unit 41 based on the determination result by the determination unit 42. Note that the reception quality calculation unit 43 may always calculate the reception quality of the same information received by the transmission / reception unit 41. Here, the reception quality includes reception power, a ratio (SIR) between reception power and interference power of the same information, an error bit rate of the same information, and the like.

  The control information generation unit 44 generates control information based on the reception quality calculated by the reception quality calculation unit 43. Specifically, the control information is information such as increasing the downlink transmission power by 10 dBm, decreasing the downlink transmission power by 5 dBm, or the difference between the reception quality calculated by the reception quality calculation unit 43 and the desired reception quality. If the base station 30a can control the downlink transmission power based on the reception quality calculated by the reception quality calculation unit 43, the control information may be the reception quality itself.

  In the present embodiment, the transmission / reception unit 41 and the control information generation unit 44 constitute transmission means.

(Operation of Mobile Communication System in this Embodiment)
Hereinafter, operations of a base station and a mobile station suitable for use in the mobile communication system according to the present embodiment will be described with reference to the drawings. FIG. 3 is a diagram showing the operation of the mobile communication system in the present embodiment.

  As shown in FIG. 3, in step 11a, the base station 30a transmits the same information to the mobile station 40a, and in step 11b, the mobile station 40a receives the same information from the base station 30a.

  In step 12, the mobile station 40a determines whether or not to transmit control information to the base station 30a. Specifically, when the mobile station 40a transmits control information to the base station 30a at a predetermined frequency (such as once every two times and once every three times) for a plurality of pieces of the same information received by the base station 30a. to decide. Further, the mobile station 40a may randomly determine whether or not to transmit control information to the base station 30a.

  If the mobile station 40a determines that the control information is to be transmitted to the base station 30a, the process proceeds to step 13, and if the mobile station 40a determines that the control information is not to be transmitted to the base station 30a, the reception of the same information transmitted by the mobile station 40a is received. It will be in a state to wait.

  In step 13, the mobile station 40a calculates the reception quality of the same information received in step 11b based on the determination result in step 12.

  In step 14, the mobile station 40 a generates control information based on the reception quality calculated in step 13.

  In step 15a, the mobile station 40a transmits the control information generated in step 14 to the base station 30a. In step 15b, the base station 30a receives the control information from the mobile station 40a.

  In Step 16, the base station 30a controls the downlink transmission power based on the control information received in Step 15b.

(Effect of mobile communication system in this embodiment)
According to the mobile communication system in the present embodiment, since the mobile station 40a transmits control information to the base station 30a only at a predetermined frequency, the mobile station 40a to the base station 30a are compared with the case where the control information is transmitted each time. Control information transmitted to the mobile communication system can be reduced, traffic of uplink radio resources can be reduced, and the amount of interference with the entire mobile communication system can be suppressed.

(First change example)
First, configurations of a base station and a mobile station suitable for use in the mobile communication system according to the first modification will be described with reference to the drawings. In the following, only differences from the above-described embodiment will be described.

  FIG. 4 is a block diagram illustrating configurations of a base station and a mobile station in the first modification. As shown in FIG. 4, the base station 30a includes a transmission / reception unit 31, a transmission power control unit 32, and a threshold setting unit 33. The mobile station 40a includes a transmission / reception unit 41, a determination unit 42, A reception quality calculation unit 43 and a control information generation unit 44 are provided.

  The threshold value setting unit 33 provided in the base station 30a is a threshold value setting means for setting a threshold value for reception quality.

  The transmission / reception unit 31 included in the base station 30a is a transmission unit that transmits the same information as the reception quality threshold set by the threshold setting unit 33 to the mobile station 40a.

  The determination unit 42 provided in the mobile station compares the reception quality calculated by the reception quality calculation unit 43 with the threshold value of the reception quality transmitted by the base station 30a, and transmits control information to the base station 30a. It is a judgment means which judges whether to do.

  Specifically, a case will be described in which the reception quality in the present embodiment is reception power and the reception power threshold is set to 10 dBm or less. When the reception power of the same information calculated by the reception quality calculation unit 43 is 5 dBm (10 dBm or less), the determination unit 42 determines that the control information is transmitted to the base station 30a, and the reception quality calculation unit 43 calculates If the received power of the same information is 15 dBm (greater than 10 dBm), it is determined that the control information is not transmitted to the base station 30a.

  Next, operations of the base station and the mobile station suitable for use in the mobile communication system in the first modification will be described with reference to the drawings. FIG. 5 is a diagram illustrating the operation of the mobile communication system in the first modification.

  As shown in FIG. 5, in step 21, the base station 30a sets a threshold value for reception quality.

  In step 22a, the base station 30a transmits the same information as the reception quality threshold set in step 21 to the mobile station 40a, and the mobile station 40a transmits the same information as the reception quality threshold to the base station 30a. Receive from station 30a.

  In step 23, the mobile station 40a calculates the reception quality of the same information received in step 22b.

  In step 24, the mobile station 40a compares the reception quality threshold received in step 22b with the reception quality of the same information calculated in step 23, and determines whether or not to transmit control information to the base station 30a. to decide.

  Specifically, a case will be described in which the reception quality in the present embodiment is reception power and the reception power threshold is set to 10 dBm or less. When the received power of the same information calculated in step 23 is 5 dBm (10 dBm or less), the mobile station 40a determines to transmit control information to the base station 30a, and receives the same information calculated in step 23. When the power is 15 dBm (greater than 10 dBm), it is determined that the control information is not transmitted to the base station 30a.

  If the mobile station 40a determines that the control information is to be transmitted to the base station 30a, the process proceeds to step 25. If the mobile station 40a determines that the control information is not to be transmitted to the base station 30a, the same information and reception received by the mobile station 40a. A state of waiting for reception of the quality threshold value is entered.

  In step 25, the mobile station 40a generates control information based on the reception quality of the same information calculated in step 23.

  In step 26a, the mobile station 40a transmits the control information generated in step 25 to the base station 30a. In step 26b, the base station 30a receives the control information from the mobile station 40a.

  In step 27, the base station 30a controls the downlink transmission power based on the control information received in step 26b.

  According to the mobile communication system in the first modified example, when the reception quality of the same information calculated by the mobile station 40a exceeds the reception quality threshold, control information is not transmitted to the base station 30a. Control information transmitted from the station 40a to the base station 30a can be reduced, traffic of uplink radio resources can be reduced, and the amount of interference with the entire mobile communication system can be suppressed.

(Second modification)
First, configurations of a base station and a mobile station that are suitable for use in the mobile communication system according to the second modification will be described with reference to the drawings. FIG. 6 is a block diagram illustrating configurations of a base station and a mobile station in the second modification. In the following, only differences from the present embodiment and the first modification will be described.

  As shown in FIG. 6, the base station 30a includes a transmission / reception unit 31, a transmission power control unit 32, and a mobile station selection unit 34. The mobile station 40a includes a transmission / reception unit 41, a reception quality calculation unit 43, And a control information generating unit 44.

  The mobile station selection unit 34 is a selection unit that selects which mobile station to transmit the control information transmission request from among the mobile stations (40a to 40c) located under the base station 30a. Here, the mobile station selection unit 34 selects a specific mobile station or a mobile station at random.

  In the following, it is assumed that the mobile station selection unit 34 has selected the mobile station 40a.

  The transmission / reception unit 31 is a transmission request transmission unit that transmits a transmission request for control information to the mobile station 40 a selected by the mobile station selection unit 34.

  Next, operations of a base station and a mobile station suitable for use in the mobile communication system in the second modification will be described with reference to FIG. FIG. 7 is a diagram illustrating the operation of the mobile communication system in the present embodiment.

  As shown in FIG. 7, in step 31, the base station 30a determines to which mobile station the control information transmission request is transmitted.

  In step 32a, the base station 30a transmits a control information transmission request to the mobile station 40a. In step 32b, the mobile station 40a receives the control information transmission request from the base station 30a.

  In step 33, the mobile station 40a calculates the reception quality of the transmission request for the control information received in step 32b.

  In step 34, the mobile station 40a generates control information based on the reception quality calculated in step 33.

  In step 35a, the mobile station 40a transmits the control information generated in step 34 to the base station 30a. In step 35b, the base station 30a receives the control information from the mobile station 40a.

  In step 36, the base station 30a controls the downlink transmission power based on the control information received in step 35b.

  According to the mobile communication system in the second modified example, only the specific mobile station selected by the base station 30a or the mobile station randomly selected by the base station 30a transmits control information to the base station 30a. Control information transmitted from the mobile station to the base station 30a can be reduced, traffic of uplink radio resources can be reduced, and the amount of interference with the entire mobile communication system can be suppressed.

It is a figure which shows the whole structure of the mobile communication system which concerns on embodiment of this invention. It is a block diagram which shows the structure of a suitable base station and mobile station used for the mobile communication system which concerns on embodiment of this invention. It is a figure which shows operation | movement of a suitable base station and a mobile station used for the mobile communication system which concerns on embodiment of this invention. It is a block diagram which shows the structure of a suitable base station and a mobile station used for the mobile communication system which concerns on the 1st modification of this invention. FIG. 6 is a diagram illustrating operations of a base station and a mobile station that are suitable for use in the mobile communication system according to the first modification of the present invention. It is a block diagram which shows the structure of a suitable base station and a mobile station used for the mobile communication system which concerns on the 2nd modification of this invention. It is a figure which shows operation | movement of a suitable base station and a mobile station used for the mobile communication system which concerns on the 2nd modification of this invention. It is a figure for demonstrating the broadcast communication which concerns on a prior art. It is a figure for demonstrating the multicast communication which concerns on a prior art.

Explanation of symbols

  101-112 mobile station, 11-17 base station, 20 radio control device, 30a-30d base station, 31 transmission / reception unit, 32 transmission power control unit 33 ... Threshold setting unit 34 ... Mobile station selection unit 40a-40j ... Mobile station 41 ... Transmitting / receiving unit 42 ... Judgment unit 43 ... Receiving quality calculation 44, control information generation unit

Claims (14)

A mobile communication system in which the same information is transmitted from a radio station to a plurality of mobile stations with a predetermined downlink transmission power,
The radio station includes a transmission power control means for controlling the predetermined downlink transmission power based on control information transmitted by a part of the mobile station located under the radio station. Communications system. A mobile communication system in which the same information is transmitted from a radio station to a plurality of mobile stations with a predetermined downlink transmission power,
The radio station is
Based on control information transmitted by the mobile station, comprising transmission power control means for controlling the predetermined downlink transmission power,
The mobile station
Determining means for determining whether to transmit the control information to the wireless station;
A mobile communication system comprising: a transmission unit configured to transmit to the radio station the control information generated based on a reception quality of the same information transmitted by the radio station based on a determination result by the determination unit. . A mobile communication system in which the same information is transmitted from a radio station to a plurality of mobile stations with a predetermined downlink transmission power,
The radio station is
Threshold setting means for setting a threshold for reception quality;
Transmitting means for transmitting to the mobile station the threshold value of the reception quality set by the threshold value setting means and the same information;
Transmission power control means for controlling the predetermined downlink transmission power based on the control information transmitted by the mobile station,
The mobile station
Reception quality calculating means for calculating the reception quality of the same information transmitted by the radio station;
A determination unit that compares the reception quality calculated by the reception quality calculation unit with a threshold value of the reception quality transmitted by the radio station and determines whether to transmit the control information to the radio station; ,
A mobile communication system comprising: a transmission unit configured to transmit the control information to the radio station based on a determination result by the determination unit. A mobile communication system in which the same information is transmitted from a radio station to a plurality of mobile stations with a predetermined downlink transmission power,
The radio station is
Mobile station selection means for selecting to which mobile station the control information transmission request is transmitted;
Transmission request transmission means for transmitting the transmission request to the mobile station selected by the mobile station selection means;
Transmission power control means for controlling the predetermined downlink transmission power based on the control information transmitted by the mobile station selected by the mobile station selection means,
The mobile station
A mobile communication system comprising: transmission means for transmitting the control information to the radio station based on the transmission request transmitted by the radio station. The transmission power control means controls the predetermined downlink transmission power based on the control information selected based on a predetermined criterion from among a plurality of the control information transmitted by the mobile station. The mobile communication system according to any one of claims 1 to 4. The transmission power control means reduces the predetermined downlink transmission power when all the control information transmitted by the mobile station is the control information instructing to decrease the predetermined downlink transmission power. The mobile communication system according to any one of claims 1 to 4, wherein the mobile communication system is characterized. The transmission power control means includes the predetermined power when the control information instructing to increase the predetermined downlink transmission power is included in the plurality of control information transmitted by the mobile station. The mobile communication system according to any one of claims 1 to 4, wherein downlink transmission power is increased. The transmission power control means decreases the control information instructing to increase the predetermined downlink transmission power or the predetermined downlink transmission power among the plurality of control information transmitted from the mobile station. 5. The mobile communication system according to claim 1, wherein the mobile communication system counts how many pieces of the control information instructing are included, and controls the predetermined downlink transmission power based on a count result. . A downlink transmission power control method for controlling a predetermined downlink transmission power when the same information is transmitted from a radio station to a plurality of mobile stations with a predetermined downlink transmission power,
Step A in which the mobile station determines whether to transmit the control information to the radio station;
Step B in which the mobile station transmits the control information generated by the reception quality of the same information transmitted by the wireless station to the wireless station based on the determination result in Step A;
A downlink transmission power control method comprising: a step C in which the radio station controls the predetermined downlink transmission power based on the control information transmitted by the mobile station. A downlink transmission power control method for controlling a predetermined downlink transmission power when the same information is transmitted from a radio station to a plurality of mobile stations with a predetermined downlink transmission power,
Step D in which the radio station sets a threshold for reception quality;
A step E in which the radio station transmits the reception quality threshold set in the step D and the same information to the mobile station;
Step F for the mobile station to calculate the reception quality of the same information transmitted by the radio station;
The mobile station compares the reception quality calculated in step F with a threshold value of the reception quality transmitted by the radio station, and determines whether to transmit the control information to the radio station. Step G,
Step H in which the mobile station transmits the control information to the radio station based on the determination result in Step G;
A downlink transmission power control method, comprising: the wireless station comprising step I for controlling the predetermined downlink transmission power based on the control information transmitted by the mobile station. A downlink transmission power control method for controlling a predetermined downlink transmission power when the same information is transmitted from a radio station to a plurality of mobile stations with a predetermined downlink transmission power,
Step J in which the radio station selects which mobile station to transmit a control information transmission request;
Step K in which the radio station transmits the transmission request to the mobile station selected in Step J;
A step L in which the mobile station transmits the control information to the wireless station based on the transmission request transmitted by the wireless station;
A downlink transmission power control method comprising: a step M in which the radio station controls the predetermined downlink transmission power based on the control information transmitted by the mobile station. A mobile station that receives the same information transmitted from a radio station with a predetermined downlink transmission power,
Determining means for determining whether or not to transmit control information to the wireless station;
A reception quality calculation means for calculating a reception quality of the same information transmitted by the wireless station based on a determination result by the determination means;
A mobile station comprising: transmission means for transmitting the control information generated based on the reception quality calculated by the reception quality calculation means to the radio station. A mobile station that receives the same information transmitted from a radio station with a predetermined downlink transmission power,
Reception quality calculating means for calculating the reception quality of the same information transmitted by the radio station;
A determination unit that compares the reception quality calculated by the reception quality calculation unit with a threshold value of the reception quality transmitted by the radio station and determines whether to transmit the control information to the radio station;
A mobile station comprising: transmission means for transmitting the control information to the radio station based on a determination result by the determination means. A wireless station that transmits the same information to a plurality of mobile stations with a predetermined downlink transmission power,
Mobile station selection means for selecting to which mobile station the control information transmission request is transmitted;
A radio station comprising: transmission power control means for controlling the predetermined downlink transmission power based on the control information transmitted by the mobile station selected by the mobile station selection means.

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