JP5293761B2 - Base station apparatus and control information transmission condition setting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base station device and a transmission condition setting method for control information in which the control information can be more stably communicated with a mobile terminal. <P>SOLUTION: The base station device 1 is configured to communicate traffic data and control information with the mobile terminal 2 and to communicate the control information using a communication connection separate from a traffic data communication connection and comprises: a detection section 11 for detecting a status of communication with the mobile terminal 2; a determination section 12 for determining the status of communication with the mobile terminal 2 on the basis of a detection result of the detection section 11; and a parameter setting section 13 for performing settings to the control information. The control information includes a parameter associated with robustness of communication of any other control information than the control information concerned. On the basis of a determination result of the determination section 12, the parameter setting section 13 sets the parameter included in the control information, thereby varying robustness of communication for the other control information in accordance with the communication status. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a base station apparatus for a wireless communication system used in a broadband mobile wireless communication system and the like, and a control information transmission condition setting method.

In recent years, as a communication system capable of covering a wide area wirelessly and providing a high-speed broadband service, for example, a broadband mobile wireless communication system (Broadband Wireless Access System) called “WiMAX” defined in IEEE 802.16, Hereinafter, the BWA system) is attracting attention.
The BWA system includes a base station apparatus and a plurality of mobile terminals that establish wireless communication with the base station apparatus. The base station apparatus transmits a broadband wireless signal to the mobile terminal. Provide communication services.
In the BWA system, in addition to transmission / reception of user data (traffic data) between the base station apparatus and the mobile terminal, transmission / reception of control information (control message), which is information necessary for controlling communication between the two, is mutually performed. Do.
As such control information, FCH (frame control header), DL-MAP (downlink subframe allocation information), UL-MAP (uplink subframe allocation information), RNG-RSP (ranging response information) transmitted by the base station apparatus side. ), And RNG-REQ (ranging request information) transmitted by the mobile terminal (for example, see Non-Patent Document 1).

Takeshi Hattori, Masanobu Fujioka, “Revised Wireless Broadband Textbook High-Speed IP Wireless”, First Edition, Impress R & D Inc., June 21, 2006, p. 177-181

In general, for traffic data communication, in order to ensure stability in the communication, parameters related to communication robustness, for example, a modulation method, a transmission output, a repetition value, and the like are appropriately set according to the communication situation. It is configured.
On the other hand, in the communication of the control information, a communication path different from the communication path (communication connection) for performing traffic data communication is used, but in the communication connection for the control information, As with traffic data communication connections, the parameters related to robustness were not adjusted. For this reason, there is a possibility that communication of control information between the base station apparatus and the mobile terminal cannot be performed stably.
Since the control information is information necessary for controlling communication between the two, it is difficult to realize stable communication unless transmission / reception is reliably performed between the base station apparatus and the mobile terminal. In some cases, communication is not possible. For this reason, a policy capable of performing control information communication more stably has been desired.
The present invention has been made in view of such circumstances, and provides a base station apparatus capable of performing control information communication with a mobile terminal more stably and a control information transmission condition setting method. For the purpose.

The present invention for achieving the above object has a function for transmitting and receiving traffic data through a base station apparatus with which communication has been established, and is necessary for controlling communication with the base station apparatus. A base station apparatus that communicates with a mobile terminal having a function for transmitting and receiving various control information, a communication state detection unit that detects a communication state with the mobile terminal, and the communication state A communication state determination unit that determines a communication state with the mobile terminal based on a detection result of the detection unit; and a setting unit that performs settings for the control information, the control information includes downlink subframe allocation information, Including other control information that is control information other than downlink subframe allocation information to be transmitted included in the downlink subframe allocation information, and parameters relating to the robustness of communication of the other control information The communication state detection unit is an uplink control information from the mobile terminal to said other control information which the base station device transmits the uplink control information is information transmitted by the request by the other control information The number of received signals is detected as the communication state, and the setting unit sets the parameter included in the control information based on a determination result of the communication state determination unit, so that the other control is performed. It is characterized by changing the robustness of information communication according to the communication state.

According to the base station apparatus configured as described above, the setting unit can set parameters related to the robustness of communication of other control information included in the control information, so the communication state with the mobile terminal Accordingly, the robustness of communication with respect to other control information can be changed, and the robustness in communication of control information can be suitably set. Thereby, communication of control information with a mobile terminal can be performed more stably.
In this case, the setting unit can set the parameter based on the reception status of the response from the mobile terminal to the transmitted control information, and can more suitably set the robustness in communication of the control information.

  In the base station apparatus, the parameter preferably includes at least one of a transmission output value and a repetition value of the other control information, and other values can be obtained by appropriately setting these values. The robustness of communication with respect to the control information can be changed according to the communication state.

Before SL communication state determining unit, the detection by the communication state detection unit results, determines the received number of the uplink control information the base station apparatus to be received, the communication state based on a predetermined threshold value The setting unit may set the parameter based on a determination result of the communication state determination unit.
Furthermore, in this case, the communication state determination unit determines whether the number of receptions of the uplink control information to be received by the base station device is greater than the threshold, and the setting unit If the non received by the communication state determination unit is determined to be smaller than the threshold value, it is preferable that a more robust highly set the parameters.

According to the above configuration, the communication state determination unit can determine whether communication of control information is properly performed based on the number of unreceived responses to be received by the base station apparatus. Furthermore, when the communication state determination unit determines that communication of control information is not properly performed, the setting unit can set parameters of other control information to be more robust. As a result, it is possible to further improve the stability of communication of control information with the mobile terminal.

In the base station apparatus, the communication state detection unit may detect a communication state for each mobile terminal, and the setting unit may set the parameter for each mobile terminal. Good.
In this case, according to the communication state of the control information for each mobile terminal, it is possible to suitably set the control information parameter for each mobile terminal, and thereby the stability of communication of control information with the mobile terminal. Can be further enhanced.

In addition, the present invention has a function for exchanging traffic data via a base station apparatus with which communication has been established, and transmission / reception of control information necessary for controlling communication with the base station apparatus A transmission condition setting method for the control information in a wireless communication system comprising: a mobile terminal having a function to perform communication; and a base station apparatus that performs communication between the mobile terminal and the control information The information relates to downlink subframe allocation information, other control information that is control information other than downlink subframe allocation information transmitted in the downlink subframe allocation information, and robustness of communication of the other control information. It includes a parameter, between the said mobile terminal and the base station apparatus, with respect to the said other control information the base station apparatus transmits, in the uplink control information from the mobile terminal I, a detecting step of detecting the number of received, which has received the uplink control information is information transmitted by the request by the other control information as the communication state, based on a detection result by said detection step, said base station apparatus A determination step for determining a communication state with the mobile terminal, a parameter setting step for setting a parameter relating to robustness of communication of the other control information based on a determination result by the determination step, and a setting step. A transmission condition setting step of transmitting the set control information to the mobile terminal and setting a transmission condition of the other control information based on the parameter.
In addition, the present invention has a function for exchanging traffic data via a base station apparatus with which communication has been established, and transmission / reception of control information necessary for controlling communication with the base station apparatus A base station apparatus that performs communication with a mobile terminal having a function to perform communication, a communication state detection unit that detects a communication state with the mobile terminal, and a detection result of the communication state detection unit A communication state determination unit that determines a communication state with the mobile terminal, and a setting unit that sets the control information. The control information includes downlink subframe allocation information and downlink subframe allocation. Including other control information which is control information other than downlink subframe allocation information transmitted in the information, and a parameter relating to communication robustness of the other control information, and the communication state detection Serves to detect the number of received radio quality response information from the mobile terminal to the wireless quality request information which the base station device transmits, as the communication state, the setting unit, the determination result of the communication state determining unit On the basis of the above, by setting the parameter included in the control information, the robustness of communication for the other control information is changed according to the communication state.
In the base station apparatus, the communication state detection unit may detect a communication state for each mobile terminal, and the setting unit may set the parameter for each mobile terminal.
In addition, the present invention has a function for exchanging traffic data via a base station apparatus with which communication has been established, and transmission / reception of control information necessary for controlling communication with the base station apparatus A transmission condition setting method for the control information in a wireless communication system, comprising: a mobile terminal having a function to perform communication; and a base station apparatus that performs communication between the mobile terminal, A detection step of detecting, as a communication state, the number of received radio quality response information from the mobile terminal for the radio quality request information transmitted by the base station device between the station device and the mobile terminal; A determination step of determining a communication state between the base station apparatus and the mobile terminal based on a detection result; and the control information based on a determination result of the determination step. A parameter setting step for setting parameters relating to robustness of communication of other control information that is control information other than the downlink subframe allocation information transmitted in the downlink subframe allocation information included in A transmission condition setting step of transmitting the set control information to the mobile terminal and setting a transmission condition of the other control information based on the parameter.

  According to the control information transmission condition setting method in the wireless communication system configured as described above, the robustness of other control information can be suitably set according to the communication state with the mobile terminal. Communication of control information with a mobile terminal can be performed more stably.

  As described above, according to the base station apparatus and the control information transmission condition setting method of the present invention, communication of control information can be performed more stably.

It is a block diagram which shows the structure of the base station apparatus 1 which is 1st embodiment of this invention. It is a figure which shows the structure of the communication frame in the radio | wireless communication performed between BS and MS. It is a figure which shows an example of control information. It is a figure which shows the aspect of the communication connection for transmitting each control information. It is a flowchart which shows the procedure of the parameter setting of the control information by BS. It is a flowchart which shows the procedure of the parameter setting of the control information by BS which is 2nd embodiment of this invention.

[First embodiment]
Next, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram showing a configuration of a base station apparatus 1 according to the first embodiment of the present invention. This base station device 1 (hereinafter also referred to as BS1) is used as a base station of a broadband mobile radio communication system, and conforms to a radio communication system called “WiMAX” defined in IEEE 802.16, for example. Communication with the mobile terminal 2 is performed by orthogonal frequency division multiple access (OFDMA). BS1 is connected to an external higher level network, and mobile terminal 2 (hereinafter also referred to as MS2) establishes communication with BS1, thereby enabling entry to an external network.

[Configuration of base station equipment]
The BS 1 has an antenna 3 for transmitting / receiving a signal for performing wireless communication with the MS 2, a transmission / reception unit 4 for transmitting / receiving a signal using the antenna 3, and a control for performing various controls relating to communication with the MS 2. Unit 5 and a communication unit 6 for connecting to an external host network.

The transmission / reception unit 4 has functions of performing signal transmission / reception with the MS 2, modulation / demodulation of transmitted / received signal waves, A / D, D / A conversion, and the like.
The control unit 5 is configured by a computer having a CPU, a memory (RAM), a storage device (hard disk and ROM), etc., and performs processing necessary for the BS 1 to establish communication with the MS 2 or the MS 2 The received information included in the communication frame of the received signal from the mobile station is extracted and transmitted to the higher level network, or the information transmitted from the higher level network to the MS 2 is loaded on the communication frame.
The control unit 5 generates control information necessary for controlling communication with the MS 2 and is a functional unit for performing transmission / reception, such as a detection unit 11, a determination unit 12, a parameter setting unit 13, And a control information generation unit 14. Each of these functional units will be described in detail later.

[About mobile terminals]
MS2 is required to control communication with BS1 in addition to having a function for entering / exchanging user data to / from the external network via BS1 with established communication. A function for transmitting and receiving various control information.
More specifically, it has a function of receiving downlink control information transmitted from BS1, generating uplink control information based on this downlink control information or by its own judgment, and transmitting it to BS1. Yes.

[About communication frames]
FIG. 2 is a diagram illustrating a configuration of a communication frame in wireless communication performed between BS1 and MS2. This communication frame is an arrangement configuration of each data expressed when the vertical axis is frequency and the horizontal axis is time. The downlink subframe to which the transmission signal transmitted by BS1 is assigned and the transmission signal transmitted by MS2 are Both subframes are alternately arranged on the time axis via gaps (TTG, RTG) of a predetermined time.

In the downlink subframe, an area P in which a preamble signal (Preamble) is stored, an area F in which a frame control header (FCH) is stored, an area D in which downlink subframe allocation information (DL-MAP) is stored, and A downlink burst area DB in which user data (hereinafter also referred to as traffic data), a part of control information, and the like are stored is allocated.
Further, the downlink burst area DB is divided into a plurality of parts in order to transmit traffic data corresponding to each MS 2 that has established communication with the BS 1. Of these, uplink subframe allocation information (UL-MAP) is stored in the downlink first burst area db1 following the area D.

In the uplink subframe, which is a transmission area for transmitting the transmission signal of MS2, in addition to the uplink burst area UB in which the uplink traffic data is stored, the ranging that MS2 transmits when requesting communication with BS1, etc. An area R in which information (RNG code) is stored is allocated.
The upstream burst area UB is divided into a plurality of parts corresponding to the respective MSs 2 that establish communication with the BS 1, and each MS 2 that establishes communications with the BS 1 transmits traffic data. Are allocated corresponding to each MS2.

  Here, the DL-MAP and UL-MAP are the above-described control information, and these are necessary for controlling communication for control information such as establishment and maintenance of communication between the BS1 and the MS2, respectively. Information.

[About control information]
Various types of control information transmitted and received between BS1 and MS2 are defined according to the purpose. FIG. 3 is a diagram illustrating an example of the control information.
As shown in FIG. 3, FCH and various control messages are defined as control information. Among these, information such as DL-MAP, UL-MAP, and DL control message belonging to the FCH and the control message is transmitted from the BS 1 to the MS 2 as downlink control information. Further, the MS 2 transmits a UL control message belonging to the control message to the BS 1 as uplink control information.
As the DL control message, information such as downlink physical channel information (DCD), uplink physical channel information (UCD), ranging response information (RNG-RSP), and radio quality request information (REP-REQ) is defined. Also, the UL control message defines information such as ranging request information (RNG-REQ) and radio quality response information (REP-RSP).

  The FCH has DL-MAP allocation information following the FCH and the like, and the MS 2 must receive it. For this reason, the modulation method is set to BPSK1 / 2.

As shown in FIG. 2, DL-MAP is information transmitted by the BS 1 using the area D in the downlink subframe, and includes information on the storage position of traffic data or the like in the downlink burst area DB.
The DL-MAP includes parameters related to transmission conditions when transmitting other downlink control information other than the DL-MAP, such as UL-MAP, DCD, UCD, RNG-RSP, and REP-REQ. . Parameters relating to DL-MAP transmission conditions are included in the FCH and transmitted. In order for the MS 2 to receive the downlink control information transmitted from the BS 1, the MS 2 needs to grasp parameters relating to the transmission conditions of the downlink control information. For this reason, BS1 includes parameters related to the transmission conditions of each downlink control information in FCH and DL-MAP and transmits them to MS2.

The parameters relating to the transmission conditions of the control information include parameters relating to robustness in communication of each control information. More specifically, as described later, transmission output values for transmitting control information, , Including repetition values.
Further, as will be described later, the control information is communicated through a communication connection that is independent from the communication connection used for the exchange of traffic data. For this reason, the BS 1 can set and transmit the setting for transmitting the control information for each communication connection separately from the setting related to the communication regarding the traffic data.

UL-MAP is information transmitted by BS1 using the downlink burst area db1 (see FIG. 2) in the downlink subframe, and the storage position of traffic data or the like in the uplink burst area UB allocated to the uplink subframe. Contains information about.
The UL-MAP includes parameters relating to transmission conditions for uplink control information such as RNG-REQ and REP-RSP transmitted by the MS 2 as other control information.

When BS1 transmits DL-MAP and UL-MAP to MS2, MS2 is allocated to itself in the storage location of traffic data addressed to itself in the downlink subframe and in the uplink subframe. The position of the upstream burst area can be grasped in order to transmit the existing traffic data.
In other words, unless the DL-MAP and UL-MAP transmitted by the BS 1 can be received, the MS 2 cannot transmit / receive traffic data at all.

  The DCD and UCD belonging to the DL control message are information regarding physical channels for downlink communication and uplink communication, respectively, and are transmitted by BS1 using a predetermined downlink burst region (for example, downlink second burst region db2 in FIG. 2). Sent.

The RNG-RSP belonging to the DL control message is an RNG code from the MS2 or RNG-REQ in the initial ranging which is a process for synchronizing transmission output and timing when the MS2 and the BS1 establish communication. The information is transmitted in response to the data, and indicates the result of ranging (transmission output and timing offset amount). This RNG-RSP is stored in a predetermined downlink burst area (for example, the second downlink burst area db2 in FIG. 2) and transmitted by BS1.
The REP-REQ belonging to the DL control message is information for requesting the MS 2 to transmit information on the radio quality such as CINR in the downlink communication, and the downlink burst assigned to the MS 2 that is the target of the radio quality. Sent by BS1 using the region.

  The RNG-REQ belonging to the UL control message is control information for requesting ranging in the initial ranging, which is a process for synchronizing transmission output and timing when the MS 2 and the BS 1 establish communication. The MAC address and CID (connection ID) of the MS 2 that transmits the RNG-REQ are included. This RNG-REQ is transmitted by the MS 2 using the uplink burst region UB in the uplink subframe.

  The REP-RSP belonging to the UL control message is information transmitted in response to the REP-REQ transmitted from the BS 1 and includes information on radio quality such as CINR in downlink communication. This REP-RSP is transmitted by the MS2 using the uplink burst area allocated to the MS2 that transmits the RNG-RSP.

MS2 and BS1 can start communication with each other by initial ranging performed by transmission / reception of the RNG-REQ and RNG-RSP.
Further, the MS 2 and the BS 1 can grasp and maintain the radio quality related to the communication established between each other by transmitting and receiving the REP-REQ and the REP-RSP.

Each control information described above transmitted / received between the BS1 and the MS2 is communicated by a communication connection independent of a communication connection for transmitting traffic data. There are five communication connections for this control information, for example, a broadcast connection, a fragmentable broadcast connection, an initial ranging connection, a basic connection, and a primary connection.
Of these, the broadcast connection and the fragmentable broadcast connection are connections for broadcasting control information from the BS 1 to an unspecified number of MSs 2. The initial ranging connection is a connection for transmitting control information for performing initial ranging. The basic connection is a connection for transmitting basic control information, and the primary connection is a connection for transmitting other control information.

FIG. 4 is a diagram showing a mode of communication connection for transmitting each control information in the present embodiment. In the figure, DL-MAP and UL-MAP are transmitted from BS1 to unspecified MS2 by a broadcast connection.
DCD and UCD are broadcast from BS1 to unspecified MS2 by a fragmentable broadcast connection.
RNG-RSP and REP-REQ are transmitted from BS1 to a predetermined MS2 through a basic connection.
The RNG-REQ is transmitted from the MS 2 to the BS 1 through the initial ranging connection.
The REP-RSP is transmitted from the MS 2 to the BS 1 through a basic connection.
As described above, the BS1 and the MS2 can transmit and receive the control information to each other through a communication connection independent of the communication connection for transmitting traffic data, and are configured to control communication. Yes.

[Setting parameters related to control information transmission conditions]
BS1 generates UL-MAP as other control information and DL-MAP including parameters related to robustness of communication as a transmission condition of DL control message, and RNG- transmitted by MS2 as other control information As a transmission condition of REQ and REP-RSP, it has a function of generating UL-MAP including parameters relating to the robustness of the communication. BS1 has a function of generating the DL control message.
The MS 2 adjusts the parameters related to the communication robustness of the RNG-REQ and REP-RSP which are UL control messages based on the parameters related to the communication robustness included in the UL-MAP transmitted from the BS 1, and The control message is configured to be transmitted to BS1.
That is, BS1 transmits UL-MAP including parameters related to robustness in communication of uplink control information such as RNG-REQ and REP-RSP to MS2, and thereby UL control message (uplink control information) transmitted by MS2 is transmitted. The transmission conditions can be adjusted.

Hereinafter, setting of the transmission conditions for each control information performed by the BS 1 will be described. As for the control information, various types of control information other than the control information shown in FIG. 3 are defined. In the present embodiment, each control information shown in FIG. 3 is indispensable for communication control. Of these, only the setting of transmission conditions will be described.
As shown in FIG. 1, the control unit 5 of the BS 1 has a function unit for generating and transmitting and receiving each downlink control information as described above, and the control unit 5 is configured as the function unit. The detection unit 11 for detecting the communication state with the MS 2, the determination unit 12 for determining the communication state with the MS 2 based on the detection result of the detection unit 11, and the control based on the determination result of the determination unit 12 A parameter setting unit 13 that sets parameters related to robustness in information communication and a control information generation unit 14 that generates control information based on the parameters set by the parameter setting unit 13 are provided.

  The detection unit 11 is a traffic data detection unit 11a that measures the number of received packets of uplink traffic data as a communication state based on the received signal from the MS 2 received by the transmission / reception unit 4, and a response to the downlink control information transmitted by the BS 1 And a control information detector 11b that counts the number of received uplink control information transmitted from the MS2 and obtains the number of unreceived uplink control information to be received by the BS 1 as a communication state based on the received number. .

In the present embodiment, the control information detection unit 11b stores how many downlink control information requiring a response is transmitted, and based on the number of received uplink control information counted by the control information detection unit 11b. It can be configured to obtain the number of unreceived uplink control information that is not returned to the transmitted downlink control information, or using ARQ (automatic retransmission request) defined in the above standard, With this ARQ function, when a reception loss occurs, the number of unacknowledged receptions can be obtained by counting the number of receptions of ACKs (acknowledgments) transmitted from the MS 2.
As uplink control information transmitted from MS2 as a response to downlink control information transmitted by BS1, RNG-REQ responded to RNG-RSP transmitted by BS1 and REP-REQ transmitted by BS1 REP-RSP that is responded to.

  The detection unit 11 can detect whether or not communication with the MS 2 is properly established by detecting the traffic data reception state as a communication state by the traffic data detection unit 11a, and control information By detecting the unreceived number that is the reception status of the uplink control information as a communication state by the detection unit 11b, it is possible to grasp whether or not the control information is properly communicated.

Based on the measurement result measured by the traffic data detection unit 11a, the determination unit 12 has a traffic data determination unit 12a that determines whether or not traffic data is received for a predetermined time, for example, X seconds, and the BS 1 And a control information determination unit 12b that determines a communication state based on the number of uplink control information that has not been received and a preset threshold value (for example, Y).
The determination unit 12 can determine the presence / absence of reception of traffic data from the MS 2 by the traffic data determination unit 12a, and the control information determination unit 12b can appropriately communicate control information based on the number of uplink control information not received. It can be determined whether or not.

  In particular, as described above, unless DL-MAP and UL-MAP are received by the MS 2, the traffic data cannot be transmitted / received at all. Therefore, when the traffic data determination unit 12a detects the traffic data reception status, the control unit 5 determines whether or not traffic data communication between the base station apparatus and the mobile terminal is properly performed. It is possible to grasp the communication state of at least DL-MAP and UL-MAP in the control information.

The parameter setting unit 13 sets parameters relating to communication robustness of downlink control information transmitted from the BS 1 and parameters relating to communication robustness of uplink control information stored and transmitted in the UL-MAP. And an uplink setting unit 13b.
Both the setting units 13a and 13b set parameters related to robustness in communication among the transmission conditions of both control information based on the determination result of the determination unit 12.
The downlink setting unit 13a sets parameters related to the robustness of communication of DL-MAP, UL-MAP, DCD, UCD, RNG-RSP, REP-REQ, and other control messages, and corresponds to the set downlink control information. Each parameter to be output is output to the control information generation unit 14.
Of the downlink control information set by the downlink setting unit 13a, parameters for the RNG-RSP, REP-REQ, and other control messages transmitted by the basic connection can be set differently for each MS2. .
The uplink setting unit 13 b sets parameters relating to RNG-REQ, REP-RSP, and other control messages, and outputs the set transmission conditions for the uplink control information to the control information generation unit 14.
Note that parameters for each of RNG-REQ, REP-RSP, and other messages can be set differently for each MS2.

The control information generation unit 14 generates UL-MAP including parameters related to robustness in communication of RNG-REQ, REP-RSP, and other messages, and also includes DL- including parameters of each set downlink control information. Other downlink control information such as MAP is generated and output to the transmission / reception unit 4.
Note that the parameters related to robustness in DL-MAP communication set by the downlink setting unit 13a are stored in the FCH and transmitted to the MS2.
The transmission / reception unit 4 receives the downlink control information (DL-MAP, UL-MAP, DCD, UCD, RNG-RSP, REP-REQ, and other messages) based on the parameters set by the downlink setting unit 13a. Send.

Both the setting units 13a and 13b can set a modulation scheme, a repetition value, and a transmission output value as parameters relating to robustness in communication of control information.
Examples of modulation schemes that can be selected include QPSK1 / 2 for DL-MAP and UL-MAP, QPSK1 / 2 to 64QAM5 / 6 for DCD, UCD, RNG-RSP, REP-REQ, and other messages, and RNG. There are QPSK1 / 2 to 16QAM3 / 4 for -REQ, REP-RSP, and other messages.
In this embodiment, these modulation methods are all fixed at QPSK1 / 2.

The repetition is a process of transmitting the same data a plurality of times, and can improve reliability in a situation where data transfer errors frequently occur. The repetition value is the number of repeated transmissions of data in this repetition. Therefore, by increasing the repetition value, the robustness of communication related to the control information can be enhanced.
This repetition value can be selected and set from four types of 0, 2, 4, and 6 times in all control information.
The transmission output value can be set in the range of −12 dB to +6 dB for UL-MAP, DCD, UCD, RNG-RSP, REP-REQ, and other messages transmitted in the downlink burst region. By increasing the transmission output value, the robustness of communication related to control information is enhanced. In the present embodiment, the transmission output values of RNG-REQ, REP-RSP, and other messages transmitted by DL-MAP and MS2 are fixed at 0 dB.

  As described above, the BS 1 sets parameters related to robustness in each communication connection for transmitting other control information included in the DL-MAP or UL-MAP based on the determination result of the determination unit 12. The robustness of communication for the other control information can be changed according to the communication state with the MS 2. In particular, for uplink control information parameters such as RNG-REQ and REP-RSP, the UL-MAP including the parameters set by the uplink setting unit 13b is transmitted to the MS 2 so that the parameters are transmitted to the control information by the MS 2. It can be reflected in communication.

Next, a procedure for setting parameters relating to robustness in communication of control information performed by the BS 1 having the above configuration will be described. In the following description, “parameters related to robustness in communication of control information” are also simply referred to as “parameters”. FIG. 5 is a flowchart showing a procedure for setting parameters of control information by BS1. In the following description, a case where communication is performed between BS1 and a plurality of MS2 will be described. In the figure, the DL control message indicates downlink control information other than FCH, DL-MAP, and UL-MAP as described above, and the UL control message is RNG-REQ, REP-RSP. , And other messages, and parameters of DL control message, UL control message, DL-MAP, and UL-MAP are shown. In the figure, “Mod” indicates a modulation method, “Rep” indicates a repetition value, and “Boost” indicates a transmission output value.
Of the above parameters, the UL control messages (RNG-REQ, REP-RSP, and other messages) that can be set differently for each MS 2 are the same for all the MSs 2 in this embodiment. Shall be set to the value of.

In the figure, “up” indicating the state of each parameter indicates that each value is adjusted and set in the direction of increasing robustness. Specifically, the repetition value and transmission It shows that the output value is set to increase the numerical value in a predetermined step. Further, “down” indicates that each value is adjusted and set in a direction in which the robustness is lowered, and indicates that each value is set to be decreased in a predetermined step. In this case, if the repetition value is set to decrease, the burst area used for repeated transmission can be reduced, and the efficiency of radio resources is set to increase. “Maintain” indicates that each value is maintained and set.
In each step in the figure, the current settings are maintained for parameters for which no settings are displayed.

The control unit 5 of the BS 1 repeatedly executes the processing shown in the flowchart shown in the figure when performing communication with the MS 2.
In the figure, the parameter setting unit 13 first performs initial setting for each parameter (step S101). As the initial setting values, as shown in the figure, the modulation schemes are all set to QPSK1 / 2, the repetition value, and the transmission output value are all set to “0”.

  Next, the control unit 5 causes the traffic data detection unit 11a to count the number of received packets of uplink traffic data and causes the control information detection unit 11b to count the number of unreceived uplink control information (step S102).

  Next, the control unit 5 causes the traffic data determination unit 12a to determine whether or not uplink traffic data has been received for X seconds (step S103). Note that the timing for starting the measurement of X seconds, which is the reference for this determination, is set when the measurement of the number of received packets is started in step S102, and is measured using, for example, a timer or the like that the control unit 5 has functionally. To do. In addition, the measurement time (X seconds) for measuring the traffic data in step S103 is set to such a time that it can be determined that the establishment of proper communication has not been performed based on whether or not uplink traffic data has been received.

If it is determined in step S103 that traffic data has not been received, the process proceeds to step S104, and the control unit 5 causes the downlink setting unit 13a to perform setting for increasing the repetition value of the DL-MAP and UL. -The setting for increasing the repetition value and the transmission output value of MAP is performed, and the setting for maintaining the current state is performed for the parameters of other control information (step S104).
Thereafter, the process returns to step S102, and the communication state with the MS 2 is detected again.

On the other hand, if it is determined in step S103 that traffic data has been received, the process proceeds to step S105, and the control unit 5 has not received the uplink control information counted by the control information detection unit 11b in the control information determination unit 12b. It is determined whether or not the number is larger than Y (step S105).
If it is determined in step S105 that the number of unreceived uplink control information is greater than Y, the process proceeds to step S106, and the control unit 5 sends the DL-MAP repetition value and UL to the downlink setting unit 13a. -A setting for maintaining the repetition value and the transmission output value of the MAP is performed, and a setting for increasing the repetition value and the transmission output value of the DL control message is performed. Further, the control unit 5 causes the uplink setting unit 13b to perform setting for increasing the repetition value of the UL control message (step S106).
Thereafter, the process returns to step S102, and the communication state with the MS 2 is detected again. It should be noted that the number of unreceived numbers (Y), which is a determination criterion in step S105, is set to a value with which it is possible to determine that communication of both control information is not properly performed.

If it is determined in step S105 that the number of unreceived uplink control information is Y or less, the process proceeds to step S107, and the control unit 5 further controls the control information detection unit 11b with respect to the control information determination unit 12b. It is determined whether the number of unreceived uplink control information to be counted is Z or less (Z <Y) (step S107).
If it is determined in step S107 that the number of unreceived uplink control information is not less than or equal to Z, the process proceeds to step S108, and the control unit 5 sends the current status for all parameters to the downlink setting unit 13a and the uplink setting unit 13b. (Step S108), and the process returns to step S102.
It should be noted that the number of unreceived numbers (Z), which is a determination criterion in step S107, is set to a value that allows determination that both pieces of control information are properly communicated.

On the other hand, if it is determined in step S107 that the number of unreceived uplink control information is Z or less, the process proceeds to step S109, and the control unit 5 sends all to the downlink setting unit 13a and the uplink setting unit 13b. The parameter value is set to be decreased (step S109).
Thereafter, the process returns to step S102, and the communication state with the MS 2 is detected again.

  According to the BS 1 configured as described above, control information other than the control information included in the control information transmitted by the BS 1 according to the communication state with the MS 2 (for example, as control information transmitted by the BS 1 By adjusting and setting parameters related to communication robustness for other control information (UL-MAP and DL control messages included in other DL-MAP), communication robustness for the other control information It can be changed according to the communication state, and robustness in communication of control information can be suitably set. That is, according to the communication state with the MS 2, the robustness in the communication of the control information can be suitably set and the control information can be transmitted, so that the control information can be more stably communicated with the MS 2. it can.

Moreover, in the said embodiment, since the detection part 11 has the control information detection part 11b, it can detect about the reception condition of each control information. In addition, since the determination unit 12 includes the above-described control information determination unit 12b, whether or not communication of control information is appropriately performed based on the number of uplink control information not received by the BS1. Can be judged.
If the number of uplink control information to be received by BS1 is large, at least one of downlink control information other than DL-MAP and UL-MAP and uplink control information with MS2 is received. Communication may not be performed properly. That is, from the BS1 side, it cannot be determined whether the downlink control information transmitted by the BS1 has not normally reached the MS2, or whether the uplink control information transmitted by the MS2 has not normally reached the BS1.
In this embodiment, when it is determined that the number of uplink control information not received by the BS 1 is larger than the predetermined threshold Y and it is determined that communication of control information is not properly performed, the DL By increasing the repetition value and transmission output value of the control message and the repetition value of the UL control message (see steps S105 and S106 in FIG. 5), the parameters of the DL control message and the UL control message are more robust. It can be set to a high setting. That is, regardless of whether the communication is not normally performed on the upstream side or the downstream side, both the upstream side and the downstream side are configured to increase robustness. As a result, it is possible to further improve the stability of communication of control information in communication with the MS 2.

Moreover, in the said embodiment, since the judgment part 12 has the above-mentioned traffic data judgment part 12a, based on the presence or absence of reception of the traffic data from MS2, is communication of control information performed appropriately? It can be determined whether or not.
If there is no reception of traffic data from MS2, there is a possibility that proper communication has not been established with MS2, and DL-MAP and UL-MAP are properly received by MS2. There is a risk of not. In the present embodiment, when it is determined that no traffic data is received from the MS 2 and it is determined that the DL-MAP and UL-MAP are not properly received by the MS 2, the DL-MAP repetition value is determined. , And UL-MAP repetition value and transmission output value are increased (see steps S103 and S104 in FIG. 5), and the DL-MAP and UL-MAP parameters are set to be more robust. Can do. As a result, it is possible to further improve the stability of communication of control information in communication with the MS 2.

[Second Embodiment]
FIG. 6 is a flowchart showing a procedure for setting parameters of control information by the BS 1 according to the second embodiment of the present invention.
In the present embodiment, the control information detection unit 11b of the detection unit 11, the control information determination unit 12b of the determination unit 12, and the parameter setting unit 13 detect and determine control information for each MS2, respectively. The case where the parameter of control information is set is shown.

In FIG. 6, steps S201, S203, and S204 are the same as steps S101, S103, and S104 of the first embodiment, respectively.
In step S202, the control unit 5 causes the traffic data detection unit 11a to count the number of received packets of the uplink traffic data, and causes the control information detection unit 11b to detect whether or not uplink control information is received for each MS 2 (step S202). S202).
If it is determined in step S203 that traffic data has been received, the process proceeds to step S205, and the control unit 5 causes the downlink setting unit 13a to perform setting for decreasing the DL-MAP repetition value and UL. -A setting is made to decrease the MAP repetition value and the transmission output value (step S205).

Next, the control unit 5 causes the control information determination unit 12b to identify the source MS2 from which the uplink control information to be received by the BS1 has not been received (step S206).
In step S207, the control unit 5 causes the downlink setting unit 13a to perform setting for increasing the repetition value and the transmission output value of the DL control message for the MS 2 specified in step S206, and the uplink setting unit 13b is set to increase the repetition value of the UL control message for the identified MS2 (step S207). Note that the DL control message in which parameters are set in step S207 is targeted for RNG-RSP and REP-RSP in which parameters can be set for each MS2.

Next, the process proceeds to step S208, and the control unit 5 causes the downlink setting unit 13a to perform a setting to decrease the repetition value and the transmission output value of the DL control message for the other MS 2 not specified in step S206. Then, the uplink setting unit 13b is set to decrease the repetition value of the UL control message for the other MS 2 (step S208). Also in this step S208, the DL control message in which parameters are set targets RNG-RSP and REP-RSP in which parameters can be set for each MS2.
Thereafter, the process returns to step S202, and the communication state with the MS 2 is detected again.

  According to the BS1 of the present embodiment, the detection unit 11 and the determination unit 12 detect and determine the communication state for each MS2, and the parameter setting unit 13 accordingly sets the control information parameters for each MS2. In accordance with the communication state of the control information for each MS 2, it is possible to suitably set parameters related to robustness in communication of control information for each MS 2.

The present invention is not limited to the above embodiments. For example, the traffic data determination unit 12a is configured to determine the communication state based on whether or not traffic data is received, but may be configured to determine the communication state based on the number of traffic data packets. In addition, the control information detection unit 11b and the control information determination unit 12b are configured to determine the number of unreceived uplink control information to be received by the BS 1 as a communication state, and determine the communication state based on the number of unreceived. However, the control information detection unit 11b may count the reception number of the uplink control information, and the control information determination unit 12b may be configured to determine the communication state based on the reception number.
Further, the parameter setting unit 13 may adjust the modulation method in the communication of each control information. In this case, the modulation method is changed from the highly robust QPSK1 / 2 to the communication of each control information. However, it may be configured to adjust up to 64QAM5 / 6 where the data transmission efficiency increases.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 BS (base station apparatus) 2 MS (mobile terminal) 3 Antenna 4 Transmission / reception part 5 Control part 6 Communication part 11 Detection part 11a Traffic data detection part 11b Control information detection part 12 Determination part 12a Traffic data determination part 12b Control information determination part 13 Parameter setting unit 13a Downlink setting unit
13b Uplink setting unit 14 Control information generation unit

Claims (8)

A function for transmitting / receiving traffic data through a base station apparatus with which communication has been established, and a function for transmitting / receiving control information necessary for controlling communication with the base station apparatus A base station apparatus that performs communication with a mobile terminal that has
A communication state detection unit for detecting a communication state with the mobile terminal;
A communication state determination unit that determines a communication state with the mobile terminal based on a detection result of the communication state detection unit;
A setting unit configured to set the control information,
The control information includes downlink subframe allocation information, other control information that is control information other than downlink subframe allocation information transmitted in the downlink subframe allocation information, and robust communication of the other control information. Includes parameters related to sex,
The communication state detection unit is configured to receive uplink control information from the mobile terminal for the other control information transmitted by the base station apparatus, and is information transmitted in response to a request by the other control information. The number of received receptions is detected as the communication state,
The setting unit changes the robustness of communication for the other control information according to the communication state by setting the parameter included in the control information based on the determination result of the communication state determination unit. A base station apparatus. Before SL communication state determining unit, the detection by the communication state detection unit results, determines the received number of the uplink control information the base station apparatus to be received, the communication state based on a predetermined threshold value Is,
The base station apparatus according to claim 1, wherein the setting unit sets the parameter based on a determination result of the communication state determination unit. The communication state determination unit determines whether or not the number of receptions of the uplink control information to be received by the base station device is greater than the threshold value.
The setting unit is configured when it is judged that the Ki受 signal number is smaller than the threshold value by the communication state determination unit, the base station apparatus according to claim 2, more robust highly set the parameters. The communication state detection unit detects a communication state for each mobile terminal,
The base station apparatus according to claim 1, wherein the setting unit sets the parameter for each mobile terminal. A function for transmitting / receiving traffic data through a base station apparatus with which communication has been established, and a function for transmitting / receiving control information necessary for controlling communication with the base station apparatus A transmission condition setting method for the control information in a wireless communication system comprising: a mobile terminal having a base station apparatus that communicates with the mobile terminal,
The control information includes downlink subframe allocation information, other control information that is control information other than downlink subframe allocation information transmitted in the downlink subframe allocation information, and robust communication of the other control information. Includes parameters related to sex,
Between the base station apparatus and the mobile terminal, uplink control information from the mobile terminal for the other control information transmitted by the base station apparatus, which is transmitted in response to a request by the other control information A detection step for detecting the number of received uplink control information as information as a communication state;
A determination step of determining a communication state between the base station apparatus and the mobile terminal based on a detection result of the detection step;
A parameter setting step for setting a parameter relating to the robustness of communication of the other control information based on the determination result of the determination step;
A transmission condition setting step of transmitting the control information set by the setting step to the mobile terminal and setting a transmission condition of the other control information based on the parameter;
A control information transmission condition setting method characterized by comprising: A function for transmitting / receiving traffic data through a base station apparatus with which communication has been established, and a function for transmitting / receiving control information necessary for controlling communication with the base station apparatus A base station apparatus that performs communication with a mobile terminal that has
A communication state detection unit for detecting a communication state with the mobile terminal;
A communication state determination unit that determines a communication state with the mobile terminal based on a detection result of the communication state detection unit;
A setting unit configured to set the control information,
The control information includes downlink subframe allocation information, other control information that is control information other than downlink subframe allocation information transmitted in the downlink subframe allocation information, and robust communication of the other control information. Includes parameters related to sex,
The communication state detection unit detects the number of receptions of wireless quality response information from the mobile terminal for the wireless quality request information transmitted by the base station device as the communication state,
The setting unit changes the robustness of communication for the other control information according to the communication state by setting the parameter included in the control information based on the determination result of the communication state determination unit. A base station apparatus. The communication state detection unit detects a communication state for each mobile terminal,
The base station apparatus according to claim 6, wherein the setting unit sets the parameter for each mobile terminal. A function for transmitting / receiving traffic data through a base station apparatus with which communication has been established, and a function for transmitting / receiving control information necessary for controlling communication with the base station apparatus A transmission condition setting method for the control information in a wireless communication system comprising: a mobile terminal having a base station apparatus that communicates with the mobile terminal,
A detection step of detecting, as a communication state, the number of receptions of radio quality response information from the mobile terminal for the radio quality request information transmitted by the base station apparatus between the base station apparatus and the mobile terminal;
A determination step of determining a communication state between the base station apparatus and the mobile terminal based on a detection result of the detection step;
Based on the determination result of the determination step, the communication information includes robustness of communication of other control information that is control information other than the downlink subframe allocation information transmitted in the downlink subframe allocation information included in the control information. A parameter setting step for setting parameters;
A transmission condition setting step of transmitting the control information set by the setting step to the mobile terminal and setting a transmission condition of the other control information based on the parameter;
A control information transmission condition setting method characterized by comprising:

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