JP5619311B2 - Mobile station, radio communication system, mobile station parameter value transmission method, and base station parameter value setting method in radio communication system - Google Patents

Description

  The present invention relates to a mobile station, a radio communication system, a parameter value transmission method for a mobile station, and a parameter value setting method for a base station in the radio communication system.

  Since temporary values are set for various parameters held by the base station when the base station is newly established, it is necessary to finely adjust various parameter values in light of the actual communication environment immediately after the new base station is established. In addition, since the communication environment changes due to the establishment of a new base station, increase / decrease in buildings, etc., it is necessary to adjust parameter values even after the establishment of a new base station. When adjusting the value (parameter value) of the transmission power of the base station, first, the measurer measures the radio field intensity and the like with a measuring device at the position where the radio signal from the base station arrives. When adjustment is necessary based on the measurement result, the measurer requests the operator of the operator center to change the value of the transmission power by telephone or the like. The operator of the operator center receiving this request changes the value of the transmission power of the base station. As a result, a new value is set for the transmission power.

  In this method, the measurer needs to continuously measure the radio field intensity of the base station and keep in contact with the operator by telephone or the like until a desired measurement result is obtained. Therefore, it takes time and effort to change the parameter value.

  Therefore, conventionally, a method for changing parameter values without involving an operator at an operator center has been proposed (see, for example, Patent Document 1). In this method, the base station transmits the values of its own parameters (transmission power, bit error rate indicating service quality, etc.) to the maintenance terminal (mobile station) for changing parameter values. Based on the transmitted parameter value, the user of the maintenance terminal or the maintenance terminal itself determines the necessity of changing the parameter value. If the parameter value needs to be changed, a change instruction is transmitted from the maintenance terminal to the base station, and the parameter value is changed by the base station.

JP 2002-246990 A

  However, the conventional method assumes that one mobile station changes the parameter value of one base station. Therefore, when there are multiple base stations that need to change parameter values, the mobile station can receive radio waves from each base station (cell) in order to ensure communication with the base station. However, it must be located near the base station and move between cells. Therefore, the more base stations that need to change the parameter value, the longer the moving distance of the mobile station, and much time is required to change the parameter values of a plurality of base stations.

  In general, a cell of a certain base station and a cell of a base station adjacent to the base station overlap in the vicinity of each cell edge (boundary of a region where radio waves from the base station reach). Therefore, in a region where a plurality of cells overlap (hereinafter referred to as a cell edge vicinity region), the mobile station may be able to communicate with a plurality of base stations. However, since the cell edge vicinity region is a region away from the base station, the communication environment is bad. In particular, since the transmission power of the mobile station is smaller than that of the base station, data from the base station can be received, but it is likely that data cannot be transmitted to the base station. Further, in the region near the cell edge, radio signals from a plurality of base stations may interfere with each other. Therefore, it is desirable to change the parameter value in consideration of the communication environment in the cell edge vicinity region. However, in the conventional method, the parameter value is changed from the information acquired by the base station itself, and the communication environment in the cell edge vicinity region is not considered. Further, in a cell edge vicinity region that is an unstable communication environment, a mobile station can transmit a parameter value to be changed to a certain base station, but cannot transmit to a certain base station. In this case, in order to change the parameter value of the base station that could not communicate, the mobile station avoids the area near the cell edge and moves by selecting an area that can communicate with the base station.

  Accordingly, an object of the present invention made in view of the above-described problems is to provide a mobile station, a wireless communication system, and a mobile that allow one mobile station to change parameter values to a plurality of base stations in a cell edge vicinity region. A parameter value transmission method for a station and a parameter value setting method for a base station in a wireless communication system.

  In order to solve the above-described problems, a mobile station according to a first aspect is configured to perform wireless communication with a base station that sets a parameter value according to acquisition of information regarding a parameter value used when transmitting a radio signal. A base station that calculates a parameter value of each base station based on reception quality of radio signals from a plurality of base stations, and transmits a radio signal that satisfies the required quality among the plurality of base stations. And transmitting a radio signal including information on the parameter values of all the plurality of base stations.

  According to a second aspect of the present invention, there is provided a wireless communication system comprising a plurality of base stations connected to each other via a network and a mobile station connected to the plurality of base stations and performing wireless communication. In the system, each base station of the plurality of base stations sets the parameter value according to acquisition of information on a parameter value used when transmitting a radio signal, and the mobile station The parameter value of each base station is calculated based on the reception quality of the radio signal from the base station, and among the plurality of base stations, the plurality of base stations that have transmitted the radio signal satisfying the required quality of the reception quality A radio signal including information on the parameter values of all the base stations is transmitted.

  As described above, the solution of the present invention has been described as an apparatus. However, the present invention can be realized as a method, a program, and a storage medium storing the program, which are substantially equivalent thereto, and the scope of the present invention. It should be understood that these are also included.

For example, a mobile station parameter value transmission method that implements the first aspect of the present invention as a method is a base station that sets a parameter value in accordance with acquisition of information related to a parameter value used when transmitting a radio signal. Calculating parameter values of each base station based on reception quality of radio signals from a plurality of base stations in a parameter value transmission method of a mobile station that performs radio communication with
Transmitting a radio signal including information on the parameter values of all of the plurality of base stations to a base station that has transmitted a radio signal whose reception quality satisfies the required quality among the plurality of base stations.

  Also, a parameter value setting method of a base station in a wireless communication system realized as a method according to the second aspect of the present invention includes a plurality of base stations connected to each other via a network, and a connection with the plurality of base stations In the base station parameter value setting method in a wireless communication system configured to perform wireless communication, each base station of the plurality of base stations relates to a parameter value used when transmitting a wireless signal The parameter value is set according to acquisition of information, and the mobile station calculates a parameter value of each base station based on reception quality of radio signals from the plurality of base stations; and Among the base stations, a radio signal including information on the parameter values of all of the plurality of base stations is transmitted to the base station that has transmitted the radio signal satisfying the required quality. It is intended to include the steps of signal, the.

  According to the mobile station, the radio communication system, and the parameter value setting method in the radio communication system according to the present invention configured as described above, a plurality of bases are transmitted only to the base station that has transmitted a radio signal whose reception quality satisfies the required quality. A radio signal including information on parameter values of all stations is transmitted, the base station sets only parameter values related to the own station among the information, and transmits parameter values not related to the own station to other base stations. . As a result, parameter values of a plurality of mobile stations can be changed if communication with at least one base station is possible in the cell edge vicinity region.

FIG. 1 is a functional block diagram showing a schematic configuration of a wireless communication system according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a positional relationship between a mobile station and a base station according to an embodiment of the present invention. FIG. 3 is a flowchart showing processing of the mobile station according to the embodiment of the present invention. FIG. 4 is a flowchart showing processing of the base station according to the embodiment of the present invention. FIG. 5 is a sequence diagram until the parameter values of the base station according to the embodiment of the present invention are set.

  Hereinafter, an embodiment according to the present invention will be described with reference to the drawings.

  FIG. 1 is a functional block diagram showing a schematic configuration of a wireless communication system according to an embodiment of the present invention. A wireless communication system 101 according to an embodiment of the present invention includes a mobile station 111 and a base station 141. The mobile station 111 is a wireless communication terminal such as a mobile phone or PHS. The base station 141 performs radio communication with the mobile station 111. For example, an eNB (evolved Node B) in an LTE (Long Term Evolution) system, and an AN (Access Network) in an HRPD (High Rate Packet Data) system. ).

  The mobile station 111 includes a mobile station antenna 113, a mobile station communication unit 115, and a mobile station control unit 117. The mobile station communication unit 115 includes a mobile station reception unit 119 that receives a radio signal from the base station 141 via the mobile station antenna 113, and a mobile station that transmits a radio signal to the base station 141 via the mobile station antenna 113. A transmission unit 121. The radio signal transmitted by the mobile station transmission unit 121 includes, for example, information on parameter values used when the base station 141 transmits a radio signal. The parameter value used when the base station 141 transmits a radio signal is, for example, an optimum value or a specified value such as transmission power, communication rate, or preamble length. Since the information on the parameter value can also include ID (Identification) information of the base station that needs to be changed, even if information on the parameter values of a plurality of base stations is transmitted together, the base station side The information can be distinguished for each base station based on the ID information. The mobile station control unit 117 controls and manages the entire mobile station 111 including each functional block of the mobile station 111. The mobile station control unit 117 is configured as software executed on any suitable processor such as a CPU (Central Processing Unit), or by a dedicated processor (for example, DSP (Digital Signal Processor)) specialized for each process. It can also be configured.

  The mobile station control unit 117 according to an embodiment of the present invention includes a maintenance target base station setting unit 123, an access target base station setting unit 125, an ID acquisition unit 127, a reception quality acquisition unit 129, and a calculation unit 131. Shall be provided. The maintenance target base station setting unit 123 determines a base station that needs maintenance, that is, a parameter value change. The access target base station setting unit 125 determines a base station to which the mobile station 111 transmits information on parameter values. The ID acquisition unit 127 acquires ID information from the radio signal received by the mobile station reception unit 119, and specifies which base station the radio signal is from. The reception quality acquisition unit 129 acquires the reception quality of the radio signal received by the mobile station reception unit 119, for example, the radio wave intensity at reception and the bit error rate. Based on the reception quality acquired by the reception quality acquisition unit 129, the calculation unit 131 determines a parameter value used when the base station transmits a radio signal. The parameter value is, for example, an optimal transmission power value with good reception quality and capable of suppressing radio signal interference from a plurality of base stations.

  The base station 141 includes a base station antenna 143, a base station communication unit 145, an inter-base station transmission / reception unit 146, and a base station control unit 147. There are a plurality of base stations 141, and the base stations are connected to each other via a network by an inter-base station transceiver unit 146 (X2 interface). The X2 interface is an interface between radio base stations defined by 3GPP (3rd Generation Partnership Project). The network connection by the X2 interface between the base stations is realized by a wire, and provides a stable communication environment as compared with the wireless network between the mobile station and the base station. The base station communication unit 145 includes a base station receiving unit 149 that receives a radio signal from the mobile station 111 via the base station antenna 143, and a base station that transmits a radio signal to the mobile station 111 via the base station antenna 143. A transmission unit 151. The inter-base station transmission / reception unit 146 transmits / receives data to / from another base station connected to the own station via the network. Data is, for example, information regarding parameter values used when each base station transmits a radio signal. The base station control unit 147 controls and manages the entire base station 141 including each functional block of the base station 141. The base station control unit 147 is configured as software executed on an arbitrary suitable processor such as a CPU (Central Processing Unit), or by a dedicated processor (for example, DSP (Digital Signal Processor)) specialized for each process. It can also be configured.

  The base station control unit 147 according to an embodiment of the present invention includes a parameter value acquisition unit 153 and a parameter value setting unit 155. The parameter value acquisition unit 153 acquires a parameter value related to the own station from information regarding the parameter value received by the base station reception unit 149 or the inter-base station transmission / reception unit 146, and sends the acquired information to the parameter value setting unit 155. . In addition, the parameter value acquisition unit 153 sends information regarding parameter values not related to the own station to the inter-base station transmission / reception unit 146. Whether the received information is related to the own station is determined based on the ID information included in the information. The parameter value acquisition unit 153 can extract only information related to the own station even when the received information includes information on a plurality of base stations. The parameter value setting unit 155 sets the parameter value related to the own station transmitted from the parameter value acquisition unit 153. As a result, the parameter value is changed.

  Subsequently, a parameter value setting method in the wireless communication system 101 will be described with reference to FIGS. 2, 3, 4, and 5. FIG. 2 is a diagram illustrating a positional relationship between a mobile station and a base station according to an embodiment of the present invention. FIG. 3 is a flowchart showing processing of the mobile station according to the embodiment of the present invention. FIG. 4 is a flowchart showing processing of the base station according to the embodiment of the present invention. FIG. 5 is a sequence diagram until the parameter values of the base station according to the embodiment of the present invention are set.

  Hereinafter, the parameter value setting of the three base stations in the situation where the mobile station 111 and the three base stations 141a, 141b, and 141c are located as shown in FIG. 2 will be described. In addition, as a reference code regarding each functional block shown in the base station 141 of FIG. 1, “a” is used for the reference code of the functional block related to the base station 141a, “b” is the reference code of the functional block related to the base station 141b, and the base station 141c. The reference numerals of the functional blocks related to the above will be described with c added. In the present embodiment, the parameter value is assumed to be the value of the transmission power of the base stations 141a to 141c.

  In FIG. 2, an area 161a indicates a range (cell) within which the radio wave of the base station 141a can reach. An area 161b indicates a range in which radio waves of the base station 141b can reach. An area 161c indicates a range where radio waves of the base station 141c can reach. In the vicinity of the cell boundary (cell edge), a plurality of cells overlap. Hereinafter, the overlapping area is referred to as a cell edge vicinity area. For example, in the cell edge vicinity region A, the mobile station 111 can receive radio signals (radio waves) from the plurality of base stations 141a to 141c. Note that the areas 161a to 161c do not guarantee that radio waves reach from the mobile station 111 to the base stations 141a to 141c. Since the mobile station 111 has a transmission output smaller than that of the base stations 141a to 141c, even if the mobile station 111 can receive radio signals from the base stations 141a to 141c, it may not be able to transmit radio signals to the base stations 141a to 141c. In particular, in the cell edge vicinity region, there is a high possibility that the mobile station 111 cannot transmit a radio signal to the base stations 141a to 141c.

  First, processing of the mobile station 111 will be described using the flowchart of FIG. The maintenance target base station setting unit 123 sets a base station (maintenance target base station) whose parameter value (transmission power value) should be changed (step S101 and 1 in FIG. 5). Hereinafter, it is assumed that the maintenance target base station setting unit 123 sets the base stations 141a to 141c as base stations that need to change parameter values. Note that the present invention is not limited to setting the maintenance target base station in advance, and the maintenance target base station setting unit 123 sets the maintenance target base station according to the reception quality of the radio signal from the base stations 141a to 141c. And can be changed.

  The mobile station 111 moves to an area where the radio signals transmitted from the base station transmitters 151 of all the base stations 141a to 141c can be received (cell edge vicinity area A), and can receive radio signals from the base stations 141a to 141c. It is determined whether or not (step S102 and 2 in FIG. 5). Whether or not the radio signals can be received from all the base stations 141a to 141c is determined by the ID acquisition unit 127 from the ID information of the base stations 141a to 141c included in the radio signals. When the mobile station reception unit 119 of the mobile station 111 can receive the radio signal transmitted from the base station transmission unit 151 of the maintenance target base station (Yes in step S102), the reception quality acquisition unit 129 The reception quality of the radio signal received by 119 is acquired (step S103 and 3 in FIG. 5). The reception quality is, for example, the radio wave intensity at the reception point or the data error rate. In the present invention, the reception quality is not limited to the quality of a radio signal related to one reception. Reception quality acquisition section 129 can also specify the average value of the quality of radio signals received over a plurality of times as the reception quality. For example, the average value of the quality of the radio signal acquired every 3 seconds for 10 minutes can be specified as the reception quality.

  Subsequently, from the reception quality acquired by the reception quality acquisition unit 129, the access target base station setting unit 125 specifies the base station that has transmitted the radio signal whose reception quality satisfies the required quality (step S104 and 4 in FIG. 5). . The required quality is a reception environment required for the mobile station 111 to communicate with the base stations 141a to 141c, and is defined by, for example, threshold values relating to reception power, data error rate, and the like. The access target base station setting unit 125 sets, as an access target base station, a base station that has transmitted a radio signal whose reception quality satisfies the required quality. Since the mobile station 111 is located in an area where radio signals can be received from the plurality of base stations 141a to 141c, that is, in the cell edge vicinity area A, depending on the transmission power of the mobile station 111 and radio signal interference, the mobile station 111 may There is a possibility that information cannot be transmitted to the base stations 141a to 141c. Therefore, if the reception quality of the radio signal from the base station is good, it is determined that the mobile station is likely to be able to transmit the radio signal to the base station, and the base station that transmitted the radio signal that satisfies the required quality is accessed. Set as the target base station. The mobile station 111 sends information on the parameter value to the base station selected for access. Note that, since the reception quality varies from moment to moment, the access target base station setting unit 125 determines whether the reception quality satisfies the required quality every time the reception quality of the radio signal varies, The access target can be changed. Hereinafter, for convenience of explanation, it is assumed that the base station 141a is the only base station that transmits a radio signal whose reception quality satisfies the required quality.

  Next, the calculation unit 131 calculates the parameter values of the base stations 141a to 141c based on the reception quality acquired by the reception quality acquisition unit 129 (step S105 and 5 in FIG. 5). For example, the calculation unit 131 considers the distance between the mobile station 111 and the base stations 141a to c, and the transmission power of the base station increases when the radio field intensity at the reception point is smaller than a desired value. When the parameter value or the radio wave intensity at the reception point is larger than a desired value, the parameter value can be specified such that the transmission power of the base station is reduced. The calculation unit 131 can also determine an optimal transmission power value from the reception quality, the degree of radio signal interference from a plurality of base stations, and the like.

  Then, the calculation unit 131 sends the calculated parameter value to the mobile station communication unit 115 in association with the ID information of the base stations 141a to 141c. The mobile station transmission unit 121 transmits a radio signal including the parameter values of all the maintenance target base stations 141a to 141c and related ID information to the access target base station 141a via the mobile station antenna 113 (step S106 and FIG. 5). 6).

  Next, processing of the base stations 141a to 141c will be described using the flowchart of FIG. The base station receiver 149a of the base station 141a receives a radio signal including a parameter value and related ID information from the mobile station 111 via the base station antenna 143a (step S111). Then, the parameter value acquisition unit 153a of the base station control unit 147a acquires only the parameter value related to the own station from the received information based on the ID information of the base stations 141a to 141c (step S112). Thereafter, the parameter value acquisition unit 153a sends the acquired parameter value to the parameter value setting unit 155a, and sends the parameter value not related to the own station and the related ID information to the inter-base station transmission / reception unit 146a.

  The parameter value setting unit 155a sets the parameter value acquired by the parameter value acquisition unit 153a to the corresponding parameter of the own station (step S113 and 7 in FIG. 5). In this embodiment, since the value of the transmission power is transmitted from the mobile station 111 as a parameter value, the value of the transmission power of the radio signal transmitted from the base station 141a to the mobile station 111 is changed in step S113.

  Of the information received by the base station 141a, the inter-base station transceiver unit 146a transmits all the information to the inter-base station transceiver unit 146b of the other base station 141b via the X2 interface. Transmit (step S114 and 8 in FIG. 5). Note that the transmission destination to which the base station 141a transmits information related to parameter values not related to the own station is not limited to the base station 141b, and can be transmitted to the base station 141c. In addition, the base station 141a does not transmit all information related to the parameter value not related to the own station to the base station 141b or 141c, and only the information related to the base station 141b is transmitted to the base station 141b based on the ID information. Only information can be transmitted to the base station 141c.

  When the inter-base station transmission / reception unit 146b of the base station 141b receives information on the parameter value from the base station 141a (step S111), the base station 141b relates to the parameter value related to its own station, as in the processing in the base station 141a. Only information is acquired and set (steps S112, S113 and 9 in FIG. 5), and information on parameter values not related to the own station is transmitted to another base station 141c (step S114, 10 in FIG. 5). When the base station 141c sets the parameter values in the same manner as the base station 141b (11 in FIG. 5), the setting of the parameter values of all the base stations 141a to 141c is completed.

  When the radio field intensity acquired by the reception quality acquisition unit 129 of the mobile station 111 is not a desired value or not within a desired range after the parameter value setting is completed, the above steps S101 to S106 and S111 to S114 are performed. Will be repeated.

  As described above, in this embodiment, when the mobile station reception unit 119 receives radio signals from the plurality of base stations 141a to 141c, the calculation unit 131 calculates the parameter value of each base station from the reception quality of the radio signals. Then, a radio signal including information on parameter values of all the base stations 141a to 141c is transmitted to the base station 141a that has transmitted the radio signal whose reception quality satisfies the required quality. When the base station receiving unit of the base station 141a receives a radio signal, the base station control unit 147 sets a parameter value related to the own station, and the inter-base station transmitting / receiving unit 146 relates to a parameter value not related to the own station. Information is transmitted to another base station 141b. That is, the mobile station 111 located in the region near the cell edge receives radio signals from the three base stations 141a to 141c whose parameter values are to be changed, and transmits radio signals including information on the parameter values to the one base station 141a. Send. Base stations 141b and 141c that do not receive information on parameter values from the mobile station 111 can acquire and change parameter values from the base station 141a or b by inter-base station connection through the X2 interface. Therefore, if the mobile station 111 can perform bidirectional communication with at least one mobile station 111, it is possible to change parameter values of a plurality of base stations. By using the inter-base station network with the X2 interface that is more stable than the radio network between the mobile station and the base station, the mobile station 111 transmits the parameter values one by one in the vicinity of the cell edge as a radio signal. The parameter values to be changed more efficiently can be delivered to the base stations 141a to 141c.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention.

  For example, functions included in each member, each means, each step, etc. can be rearranged so as not to be logically contradictory, and a plurality of means, steps, etc. can be combined or divided into one. Is possible.

DESCRIPTION OF SYMBOLS 101 Wireless communication system 111 Mobile station 113 Mobile station antenna 115 Mobile station communication part 117 Mobile station control part 119 Mobile station reception part 121 Mobile station transmission part 123 Maintenance target base station setting part 125 Access target base station setting part 127 ID acquisition part 129 Reception quality acquisition unit 131 Calculation unit 141, 141a, 141b, 141c Base station 143 Base station antenna 145 Base station communication unit 146 Inter-base station transmission / reception unit 147 Base station control unit 149 Base station reception unit 151 Base station transmission unit 153 Parameter value acquisition Part 155 Parameter value setting part 161a, 161b, 161c area A Cell edge vicinity area

Claims (4)

A mobile station that performs radio communication with a base station that sets the parameter value according to acquisition of information on the parameter value used when transmitting a radio signal,
A parameter value of each base station is calculated based on reception quality of radio signals from a plurality of base stations, and among the plurality of base stations, the plurality of base stations that have transmitted radio signals satisfying the required quality of reception quality A mobile station that transmits a radio signal including information on the parameter values of all base stations. A wireless communication system comprising a plurality of base stations connected to each other via a network and a mobile station that performs wireless communication by connecting to the plurality of base stations,
Each base station of the plurality of base stations sets the parameter value according to the acquisition of information on the parameter value used when transmitting a radio signal,
The mobile station calculates a parameter value of each base station based on reception quality of radio signals from the plurality of base stations, and transmits a radio signal satisfying required quality among the plurality of base stations. A radio communication system that transmits a radio signal including information on the parameter values of all of the plurality of base stations to a base station. In the parameter value transmission method of the mobile station that performs radio communication with the base station that sets the parameter value according to the acquisition of information on the parameter value used when transmitting the radio signal,
Calculating a parameter value of each base station based on reception quality of radio signals from a plurality of base stations;
Transmitting a radio signal including information on the parameter values of all of the plurality of base stations to a base station that has transmitted a radio signal satisfying a required quality among the plurality of base stations. Parameter value transmission method. In the parameter value setting method of a base station in a wireless communication system composed of a plurality of base stations connected to each other via a network and a mobile station connected to the plurality of base stations and performing wireless communication,
Each base station of the plurality of base stations sets the parameter value according to the acquisition of information on the parameter value used when transmitting a radio signal,
The mobile station is
Calculating a parameter value of each base station based on reception quality of radio signals from the plurality of base stations;
Transmitting a radio signal including information on the parameter values of all of the plurality of base stations to a base station that has transmitted a radio signal satisfying a required quality among the plurality of base stations. A parameter value setting method for base stations in the system.

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