JP5664944B2 - Base station and radio resource setting method - Google Patents

Description

  The present invention relates to a radio communication system in a heterogeneous network, and more particularly to a technique for setting radio resources in a radio communication system.

  3GPP (3rd Generation Partnership Project) LTE Advanced (Long Term Evolution Advanced) improves the capacity and / or radio coverage of a macro cellular network built only from macro base stations (hereinafter referred to as MeNB (Macro evolved Node B)) He is considering a heterogeneous cellular network. A heterogeneous cellular network is a network in which heterogeneous base stations are deployed such that a low power node (LPN) is embedded in a macro cellular network. LPN can provide access to a core network to a user terminal (hereinafter referred to as UE (User Equipment)) through a radio link, like MeNB, but has lower transmission power than MeNB. Examples of network nodes classified as LPN include PeNB (Pico eNB, pico eNB), HeNB (Home eNB, home eNB), and RN (Relay Node, relay node). The PeNB is an LPN having a wired backhaul connection to the core network and is accessible to all UEs. The HeNB is an LPN having a wired backhaul connection to the core network, but can only be accessed by UEs belonging to a limited subscriber group (CSG). The RN connects to the core network through the MeNB via the wireless backhaul link and is accessible to all UEs. As an example of the main RN deployment situation, the MeNB that manages the RN is configured to allocate a part of the time domain resource called a backhaul subframe in the system radio resource in order to communicate with the RN. On the other hand, in another part of the time domain resource, the MeNB and RN can communicate with each UE simultaneously (see Non-Patent Document 1).

  In this specification, the term LPN is used to mean PeNB, HeNB, or RN in common, and the term LPN-UE is used to mean UE that has established a connection with the LPN. On the other hand, the terms PeNB-UE, HeNB-UE, and RN-UE are used to mean UEs that have established connections with PeNB, HeNB, and RN, respectively. The term MeNB-UE is used to mean a UE that has established a connection with the MeNB.

  One issue with heterogeneous networks currently under consideration by the 3GPP RAN Working Group (RAN WG) is that when the MeNB and LPN communicate the control channel, user data, and reference signal with each UE on the same carrier frequency. Interference between MeNB and LPN is mentioned (refer nonpatent literature 2). This problem can be further divided into cases where the MeNB causes interference to the LPN and vice versa.

  One of the main interference situations from LPNs to MeNB-UEs in heterogeneous networks is that LPNs cause significant interference, especially for MeNB-UEs located near the LPNs. As a result, the throughput performance in the MeNB-UE deteriorates. In order to deal with such an interference problem, Non-Patent Document 3 discloses several techniques such as time shifting, carrier off-setting and power control for superimposed carriers as techniques used to protect the macro downlink control channel. Technology is disclosed. For example, when LPN and MeNB are time synchronized, time shifting of LPN transmission to MeNB downlink frame timing can be used. When performing power control, the LPN sets its own transmit power by measuring the surrounding RF conditions of the macro cell to reduce interference to the MeNB-UE and maintain good LPN coverage for the LPN-UE To do.

3GPP TR 36.814 v9.0.0 (2010-03), "Further Advancements for E-UTRA physical layer aspects" 3GPP RP-100383, "New Work Item Proposal: Enhanced ICIC for non-CA based deployments of heterogeneous networks for LTE" 3GPP TR 36.921 v9.0.0 (2010-03), "HeNB RF requirements analysis"

  When the heterogeneous network uses the technique disclosed in Non-Patent Document 3, the LPN is based on the assumption that the MeNB always transmits user data to the MeNB-UE and the LPN always causes interference to the MeNB-UE. -LPN transmission power or system radio resource amount allocated for transmission to UE is controlled statically or semi-statically. However, since the MeNB actually does not always transmit user data to the MeNB-UE, in the method disclosed in Non-Patent Document 3, the transmission power or allocated resource amount in the LPN is controlled more than necessary. Will end up. Accordingly, the problem of throughput performance degradation in LPN still remains.

  Accordingly, the present invention has been achieved in view of the above-described problems, and its object is to achieve low power node throughput without causing additional interference to communication at a macro base station in a heterogeneous network. It is to provide a base station and a radio resource setting method in a communication system that can improve performance.

According to the present invention, there is provided a base station located in a first radio coverage of a first base station in a communication system. The base station has a lower transmission power than the first base station. Base station includes storage means for previously storing a system resource allocation information about the first part and divided system radio resources and a second portion at least a time domain, based on the system resource allocation information, the first Control means for changing the setting of the transmission power of the base station between the first part and the second part, wherein the first part and the second part are the base station and the first part. The first part is usable for both base stations, and the first base station uses the first part for user data communication with a terminal connected to the first base station, and the user data communication The second part is used for at least one function of the first base station other than .
According to the present invention, a base station having radio coverage in which a low power node is arranged is provided. The low power node has a lower transmission power than the base station. The base station, when using a memory means for previously storing a system resource allocation information about the first part and divided system radio resources and a second portion at least the time domain, the first portion A scheduler that executes a user data communication function for transmitting user data to a terminal connected to the base station and executes at least one function other than the user data communication when using the second portion And have. The first part and the second part are usable in both the low power node and the base station, and the low power node is configured to use the first part and the base part based on the system resource allocation information. The transmission power setting of the low power node is changed between the second part and the second part.

According to the present invention, a first base station and at least one second base station that is in radio coverage of the first base station and has a lower transmission power than the first base station; A communication system is provided having at least one terminal connected to each of the first and second base stations. The first base station, a first storage unit for storing the system resource allocation information about the first part and divided system radio resources and a second portion at least the time domain, the first portion It performs user data communication function of transmitting the user data to a terminal connected to the first base station when using, the non-user data communication when using the second portion And a scheduler that executes at least one function. The second base station is a second storage unit that stores the system resource allocation information in advance , and based on the system resource allocation information, between the first part and the second part. Control means for changing the transmission power setting of the base station .

ADVANTAGE OF THE INVENTION According to this invention, the setting method of the radio | wireless resource in the base station arrange | positioned in the 1st radio | wireless coverage of the 1st base station in a communication system is provided. The base station has a lower transmission power than the first base station. The method includes the steps of storing in advance a system resource allocation information about the first part and divided system radio resources and a second portion at least a time domain, based on the system resource allocation information, the first possess and changing the setting of the transmission power of the base station between portion and said second portion, said first portion and said second portion is the base station and the first base station The first part is used for user data communication with a terminal connected to the first base station, and the first base station uses the first part other than the user data communication. The second part is used for at least one function of the first base station .
ADVANTAGE OF THE INVENTION According to this invention, the setting method of the radio | wireless resource in the base station which has the radio | wireless coverage by which the low power node is arrange | positioned is provided. The low power node has a lower transmission power than the base station. The method comprises the steps of storing system resource allocation information relating to system radio resources divided into a first part and a second part at least in the time domain; and when using the first part , the base Executing a user data communication function for transmitting user data to a terminal connected to the station; and executing at least one function other than the user data communication when using the second portion; Have. The first part and the second part can be used in both the low power node and the base station, and the low power node is connected to the first part and the base part based on the system resource allocation information. The transmission power setting of the low power node is changed between the second part and the second part .

  As described above, according to the present invention, it is possible to improve the throughput performance of a low power node without causing additional interference with communication in a macro base station in a heterogeneous network.

FIG. 1 is a schematic diagram illustrating a wireless communication system commonly used in exemplary embodiments of the present invention. FIG. 2 is a block diagram of an exemplary configuration of a first base station that is common to exemplary embodiments of the present invention. FIG. 3 is a block diagram of an exemplary configuration of a second base station that is common to exemplary embodiments of the invention. FIG. 4 is a block diagram of an exemplary configuration of user terminals that is common to exemplary embodiments of the present invention. FIG. 5 is a schematic diagram illustrating setting of system radio resources and setting of transmission power of the LPN used by the MeNB and LPN according to the first exemplary embodiment of the present invention. FIG. 6 is a sequence diagram illustrating a radio link parameter setting method in the second base station according to the first exemplary embodiment. FIG. 7 is a flowchart of an exemplary operation in the second base station according to the first exemplary embodiment. FIG. 8 is a schematic diagram of another configuration of system radio resources according to the first exemplary embodiment. FIG. 9 is a schematic diagram illustrating setting of system radio resources used by the MeNB and LPN and setting of a ratio of the second resource part to the system radio resources according to the first exemplary embodiment. FIG. 10 is a schematic diagram illustrating system radio resource setting and LPN transmission power setting according to the second exemplary embodiment of the present invention. FIG. 11 is a sequence diagram illustrating a radio link parameter setting method in the second base station according to the second exemplary embodiment. FIG. 12 is a flowchart of an exemplary operation in the first base station according to the second exemplary embodiment. FIG. 13 is a schematic diagram illustrating a wireless communication system according to a third exemplary embodiment of the present invention. FIG. 14 is a sequence diagram illustrating a radio link parameter setting method in the second base station according to the third exemplary embodiment. FIG. 15 is a flowchart of an exemplary operation in the first base station according to the third exemplary embodiment. FIG. 16 is a flowchart of an exemplary operation in the third base station according to the third exemplary embodiment. FIG. 17 is a schematic diagram illustrating a wireless communication system according to a fourth exemplary embodiment of the present invention. FIG. 18 is a sequence diagram illustrating a radio link parameter setting method in the second base station according to the fourth exemplary embodiment. FIG. 19 is a flowchart of an exemplary operation in the first base station according to the fourth exemplary embodiment. FIG. 20 is a flowchart of an exemplary operation in the second base station according to the fourth exemplary embodiment.

  Preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1. System Hereinafter, the details disclosed in this section of the specification are common to all embodiments described below, unless expressly specified otherwise.

  As shown in FIG. 1, for simplicity, the wireless communication system includes a first base station 10, a second base station 20, a terminal 30A connected to the first base station 10, and a second base station. Suppose that a terminal 30B connected to 20 is included. In this figure, the first base station 10, the second base station 20, the terminal 30A and the terminal 30B respectively correspond to the MeNB, LPN, MeNB-UE and LPN-UE as described above. Hereinafter, these abbreviations are used.

  The MeNB 10 generates radio coverage of the MeNB cell 51, and the LPN 20 generates smaller radio coverage of the LPN cell 52 in the MeNB cell 51. MeNB 10 and LPN 20 each share the same system radio resource 40 (eg, frequency) to communicate user data with MeNB-UE and LPN-UE. Details of the system radio resource will be described later. In the following description, it is assumed that the wireless communication system is an OFDMA (Orthogonal Frequency Division Multiple Access) wireless communication system such as LTE Advanced.

1.1) Macro base station (MeNB)
As illustrated in FIG. 2, the MeNB 10 includes a wireless communication unit 101. The radio communication unit 101 performs radio communication with the MeNB-UE 30A and / or a relay node (hereinafter referred to as RN) through an antenna. The radio communication unit 101 receives an uplink signal from the MeNB-UE 30A and / or RN, and outputs the uplink reception signal to the reception data processor 102. Received data processor 102 performs procedures such as signal synthesis, demodulation, and channel decoding to obtain user data from the uplink received signal. Received user data obtained as a result is transferred to the core network through the communication unit 103.

  The transmission data processor 104 receives user data from the core network through the communication unit 103, and performs channel coding, rate matching, and interleaving on the user data to generate a transport channel. Then, the transmission data processor 104 adds control information to the transport channel to generate a radio frame. In addition, the transmission data processor 104 performs symbol mapping to generate transmission symbols. The radio communication unit 101 modulates and amplifies the transmission symbol to generate a downlink signal, and then transmits the downlink signal to the MeNB-UE 30A through the antenna.

  The scheduler 105 refers to the system radio resource allocation information (hereinafter referred to as system resource allocation information) in the MeNB 10 stored in the memory 106, thereby transmitting and receiving user data to and from the MeNB-UE 30 </ b> A. Control distribution. The system radio resource is allocated in such a way that a part of the system radio resource is allocated for the MeNB 10 to communicate user data with the MeNB-UE 30A, and the MeNB 10 executes at least one function other than the function of communicating user data with the MeNB-UE 30A. Is determined in advance so that another part can be allocated. Details of the allocation and the method for determining the allocation will be described later.

  Further, the scheduler 105 transmits the system resource allocation information stored in the memory 106 to the LPN 20 via the transmission data processor 104, the wireless communication unit 101, and the antenna via the wireless link, or receives the reception data processor 102 and the communication. The data is transmitted via the core network through the unit 103. The scheduler 105 may be realized by a software program executed on a program control processor such as a CPU (Central Processing Unit).

1.2) Low power base station (LPN)
As shown in FIG. 3, the LPN 20 is assumed to have the same functionality as the MeNB 10 with some exceptions that are explicitly described below. Similarly to the wireless communication unit 101 of the MeNB 10, the wireless communication unit 201 receives an uplink signal from the LPN-UE 30B through the antenna. The reception data processor 202 transfers the reception user data to the core network or the MeNB through the communication unit 203 in the same manner as the reception data processor 102 of the MeNB 10. Similar to the transmission data processor 104 of the MeNB 10, the transmission data processor 204 generates a transmission symbol based on user data received from the core network or the MeNB through the communication unit 203. And the radio | wireless communication part 201 produces | generates a downlink signal from a transmission symbol, and transmits it to LPN-UE30B.

  The scheduler 205 controls radio resource allocation for transmitting and receiving user data to and from the LPN-UE 30B by considering the system radio resource settings provided by the resource setting controller 207. The resource setting controller 207 sets a radio link parameter of a system radio resource for communicating user data with the LPN-UE 30B based on the system resource allocation information stored in the memory 206. The radio link parameter may be a ratio of resources allocated to communicate user data with the LPN-UE 30B to transmission power and / or system radio resources. The system resource allocation information can be received from the MeNB via a radio link through the radio communication unit 201 and the reception data processor 202, or via a core network through the communication unit 203 and the transmission data processor 204. The received system resource allocation information is stored in the memory 206 through the scheduler 205 and the resource setting controller 207. Alternatively, the system resource allocation information can be pre-defined by the network operator and stored in the memory 206. The resource setting controller 207 can also transmit the set transmission power information to the LPN-UE 30B through the scheduler 205, the transmission data processor 204, the wireless communication unit 201, and the antenna. The scheduler 205 and the resource setting controller 207 may be realized by a software program executed on a program control processor such as a CPU (central processing unit).

1.3) Terminal (UE)
FIG. 4 shows an exemplary configuration of the UE 30. UE30 means both MeNB-UE30A and LPN-UE30B. The radio communication unit 301 receives a downlink signal from the MeNB 10 or the LPN 20 through the antenna. The received data processor 302 performs the process of obtaining user data from the received downlink signal and forwards the user data to the processor 304 that controls the operation of the UE 30. Further, the reception data processor 302 can receive the set transmission power information from the LPN 20 through the wireless link communication unit 301 and store it in the memory 303. Based on the set transmission power information, the reception data processor 302 calculates a power offset value when calculating RSRP (Reference Signal Received Power) or RSRQ (Reference Signal Received Quality). Can be set. RSRP or RSRQ indicates the quality of the radio link between the LPN 20 and the LPN-UE 30B. When user data to be transmitted is generated, the processor 304 outputs the user data to the transmission data processor 306 under the control of the transmission data controller 305. The radio communication unit 301 generates an uplink signal from user data received from the transmission data processor 306 and transmits it to the MeNB 10 or the LPN 20.

2. 1st exemplary embodiment 1st exemplary embodiment is as radio link parameter of the system radio | wireless resource for LPN20 to transmit user data to LPN-UE30B based on the allocation information of the system radio | wireless resource in MeNB10. The case where transmission power is set is shown. Since this embodiment assumes a wireless communication system similar to that described above with reference to FIGS. Details specific to this embodiment will be described with reference to FIGS.

2.1) Example of Resource Setting As an example for explaining the present embodiment, FIG. 5 shows the setting of the system radio resource 40 used by the MeNB 10 and the LPN 20, and the control of the LPN 20 by the set system radio resource. Transmission power. In this resource setting, the system radio resource 40 is divided into a first resource portion 41 and a second resource portion 42 in the time domain.

  In the MeNB 10, it is assumed that the system radio resources are set in advance as shown in FIG. The MeNB 10 is configured to allocate a first resource part 41 for transmitting user data to the MeNB-UE 30A and a second resource part 42 for functions other than transmitting user data to the MeNB-UE 30A. The In LPN, the system radio resource configuration radio link parameter is assumed to be its own transmission power. As illustrated in FIG. 5, the transmission power of the LPN 20 is reduced to the power value P <b> 1 during the period corresponding to each first resource portion 41 for the MeNB 10 to transmit user data to the MeNB-UE. The power value P1 is smaller than the maximum transmission power P2 (= Pmax) by a predetermined power decrease value ΔP. The power reduction value ΔP is determined so as to obtain effective mitigation of interference from the LPN to the MeNB-UE. During the period corresponding to each second resource portion 42 in which the MeNB 10 does not transmit user data to the MeNB-UE 30A, the LPN 20 increases its own transmission power to increase the power value for transmitting user data to the LPN-UE 30B. Or it is usually set to a power value set in advance. In this way, the radio link parameters for the LPN 20 are controlled according to which of the first resource portion 41 and the second resource portion 42 is scheduled according to the system resource allocation information.

2.2) Operation As shown in FIG. 6, the system resource allocation information received from the MeNB 10 or set in advance by the operator as described above is stored in the memory 206 of the LPN 20 (step S1101). Then, the resource setting controller 207 of the LPN 20 sets transmission power for transmitting user data to the LPN-UE 30B based on the system resource allocation information in the MeNB 10 stored in the memory 206 (step S1102).

  In the time index corresponding to each of the first resource portions 41, the resource setting controller 207 sets the transmission power to P1. P1 is obtained by subtracting a predetermined power decrease value (ΔP) from the maximum transmission power (Pmax) of the LPN 20 (step S1103). Then, the resource setting controller 207 controls the scheduler 205 to allocate the first resource portion 41 to transmit user data to the LPN-UE 30B with the set transmission power P1 (step S1104). Thereafter, the LPN 20 transmits user data to the LPN-UE 30B (step S1105).

  On the other hand, in the time index corresponding to each of the second resource portions 42, the resource setting controller 207 sets the transmission power to P2. P2 is equal to Pmax (step S1106). Then, the resource setting controller 207 controls the scheduler 205 to allocate the second resource portion 42 to transmit user data to the LPN-UE 30B with the set transmission power P2 (step S1107). Then, the LPN 20 transmits user data to the LPN-UE 30B (step S1108).

  In FIG. 7, it is assumed that the memory 206 has already stored the system resource allocation information as described above. In step S1201, the scheduler 205 determines whether it is the start of a new time index for user data transmission. If it is not yet the time (No in S1201), the scheduler 205 repeats step S1201. If it is that time (Yes in S1201), the scheduler 205 instructs the resource setting controller 207 to read the system resource allocation information from the memory 206 (step S1202). Then, the resource setting controller 207 determines to which part of the radio resource the current time index corresponds (step S1203). When the current time index corresponds to the first resource part (first resource part of S1203), the resource setting controller 207 sets the transmission power to P1 = Pmax−ΔP (step S1204) and controls the scheduler 205. Then, the first resource portion 41 is allocated to transmit user data to the LPN-UE 30B with the set transmission power P1 (step S1205).

  On the other hand, when the current time index corresponds to the second resource part (second resource part of S1203), the resource setting controller 207 sets the transmission power to P2 = Pmax (step S1206) and controls the scheduler 205. Then, the second resource portion 42 is allocated to transmit user data to the LPN-UE 30B with the set transmission power P2 (step S1207). After the assignment is completed (step S1205 or S1207), the LPN 20 transmits user data to the LPN-UE 30B with the set transmission power (step S1208). Then, the process returns to step S1201. Since the operation of the UE as shown in FIG. 4 is general knowledge of those skilled in the art, description thereof is omitted.

2.3) Other Examples The resource settings of the system radio resource 40 as disclosed in FIG. 5 are shown for the purpose of explanation, and the present embodiment is not limited to this example. As another example, the system radio resources are two separate sets of time and frequency coordination resources, ie, a first set of first resource portions 41 and a second resource portion 42 as shown in FIG. It can also be divided into two sets. MeNB10 transmits user data to MeNB-UE using the 1st resource part 41, and performs functions other than transmission of user data using the 2nd resource part 42. FIG. In this case, the LPN sets its own transmission power such that the transmission power in the second resource portion 42 is larger than the transmission power in the first resource portion 41.

  Moreover, the setting of the transmission powers P1 and P2 as described above is shown for the purpose of explanation, and the present embodiment is not limited to the example. As another example, the transmission power P1 can be a predetermined transmission power (Pdef) less than Pmax, and the transmission power P2 can be a value obtained by adding a predetermined power increase value to Pdef. is there.

  Referring to FIG. 9, a ratio of resources allocated to transmit user data to the LPN-UE 30 </ b> B with respect to system radio resources may be used as configuration radio link parameters in the LPN 20 instead of transmission power. In this case, under the assumption of system radio resources as disclosed in FIG. 8, the LPN 20 determines that the ratio (R2) of the second resource part is higher than the ratio (R1) of the first resource part at each time index. Set to be larger. Such a ratio setting is considered to be as effective as the transmission power setting as described above. It is also effective to set both the transmission power and the allocated resource ratio.

2.4) Effect As described above, according to the resource configuration according to the present embodiment, the LPN 20 transmits user data to the LPN-UE 30B when the MeNB 10 is not transmitting user data to the MeNB-UE 30A. It is possible to increase its own transmission power. Thereby, the signal-to-interference noise ratio (SINR) in the radio link between the LPN 20 and the LPN-UE 30B is improved. Accordingly, the throughput performance of the LPN 20 can be improved by the improved SINR without causing additional interference to the MeNB-UE 30A.

3. Second Exemplary Embodiment The second exemplary embodiment is limited in that the MeNB 10 transmits a control channel and / or a reference signal so that effective mitigation of interference from the MeNB to the LPN-UE is obtained. In this case, the second resource portion is allocated for use. Since this embodiment assumes a wireless communication system similar to that described above with reference to FIGS. Details specific to this embodiment will be described with reference to FIGS.

3.1) Resource Setting Example As an example for explaining the present embodiment, FIG. 10 shows the setting of the system radio resource 40 used by the MeNB 10 and the LPN 20, and the control of the LPN 20 by the set system radio resource. Transmission power. In this resource setting, the system radio resource 40 is divided into a first resource portion 41 and a second resource portion 42 in the time domain. It should be noted that the present embodiment provides two distinct sets of time / frequency coordination resources: a first set of first resource portions 41 and a second set of second resource portions 42 as shown in FIG. It can also be applied to system radio resources divided into.

  In the MeNB 10, it is assumed that the system radio resources are set in advance as illustrated in FIG. The MeNB 10 allocates a first resource part 41 for transmitting user data to the MeNB-UE 30A and a second resource part 42 for restricted use for transmitting control channels and / or reference signals. Composed. In LPN, the system radio resource configuration radio link parameter is assumed to be its own transmission power. As illustrated in FIG. 10, the transmission power of the LPN 20 is reduced to the power value P1 during a period corresponding to each first resource portion 41 for the MeNB 10 to transmit user data to the MeNB-UE. The power value P1 is smaller than the maximum transmission power P2 (= Pmax) by a predetermined power decrease value ΔP. The power reduction value ΔP is determined so as to obtain effective mitigation of interference from the LPN to the MeNB-UE. During the period corresponding to each second resource portion 42, the MeNB 10 restricts transmission to the control channel and / or reference signal, while the LPN 20 transmits its own transmission power to the LPN-UE 30B. Set to an increased power value for.

3.2) Operation FIG. 11 shows an exemplary sequence diagram of a second exemplary embodiment with the above assumptions. Since the operation steps of the LPN 20 in this embodiment are the same as steps S1101 to S1108 of the first exemplary embodiment in FIG. 6, the same reference numerals are used in FIG.

  Referring to FIG. 11, predetermined system resource allocation information in MeNB 10 as described above is stored in memory 106 in step S1301. In the time index corresponding to the first resource portion, the scheduler 105 allocates the first resource portion to transmit user data to the MeNB-UE 30A based on the system resource allocation information stored in the memory 106 ( Step S1302). And MeNB10 transmits user data to MeNB-UE30A (step S1303). On the other hand, in the time index corresponding to the second resource part, the scheduler 105 limits the resource allocation and transmission process (step S1304). Since the operation of the LPN 20 in this embodiment is the same as that of the first embodiment, the description thereof is omitted.

  With reference to FIG. 12, it is assumed that the memory 106 has already memorize | stored the system resource allocation information in MeNB10 as mentioned above. In step S1401, the scheduler 105 determines whether it is the start of a new time index for user data transmission (step S1401). If it is not yet the time (No in S1401), the scheduler 105 repeats step S1401. If it is that time (Yes in S1401), the scheduler 105 reads the system resource allocation information in the MeNB from the memory 106 (step S1402). Then, the scheduler 105 determines to which part of the radio resource the current time index corresponds (step S1403).

  When the current time index corresponds to the first resource part (first resource part of S1403), the scheduler 105 allocates the first resource part to transmit user data to the MeNB-UE 30A (step S1404). . And user data are transmitted to MeNB-UE30A through the radio | wireless communication part 101 (step S1405). On the other hand, if the current time index corresponds to the second resource part (second resource part of S1403), the scheduler 105 limits the allocation and transmission of the second resource part (step S1406). After transmission (step S1405) or allocation and transmission restrictions (step S1406), the process returns to step S1401. Since the operation of the UE as shown in FIG. 4 is general knowledge of those skilled in the art, description thereof is omitted.

  The system radio resource allocation in the MeNB as described above is shown for the purpose of explanation, and the present embodiment is not limited to the method. As another example, instead of or in addition to transmit power, LPN 20 may be allocated resources to transmit user data to LPN-UE 30B for system radio resources, as disclosed in the first exemplary embodiment. It is also possible to set the ratio.

3.3) Effect As described above, according to the resource configuration according to the present embodiment, when the MeNB 10 restricts its transmission process, the LPN 20 has its own transmission power for transmitting user data to the LPN-UE 30B. In addition to the increase, interference in the LPN-UE 30B from the MeNB 10 can be reduced. This further improves the signal-to-interference and noise ratio (SINR) in the radio link between the LPN 20 and the LPN-UE 30B compared to the first exemplary embodiment. Therefore, the throughput performance of the LPN 20 can be further improved without causing both the additional interference of the LPN 20 with respect to the MeNB-UE 30A and the additional interference of the MeNB 10 with respect to the LPN-UE 30B.

4). Third Exemplary Embodiment In the second exemplary embodiment, the case where the MeNB 10 allocates the second resource part for limited transmission to reduce interference from the MeNB to the LPN-UE is shown. However, in the third exemplary embodiment, a case is shown in which the MeNB 10 allocates a second resource part to transmit user data to a third base station, ie, a relay node (RN). Details of this embodiment are described below.

4.1) System As shown in FIG. 13, for simplicity, the wireless communication system includes a first base station (MeNB) 10, a second base station (LPN) 20, and a third base station (RN) 20. -1, connected to the first base station (MeNB-UE) 30A, connected to the second base station (LPN-UE) 30B, and connected to the third base station Assume that it includes a terminal (RN-UE) 30B-1. MeNB10, LPN20, and RN20-1 generate | occur | produce the radio | wireless coverage of MeNB cell 51, LPN cell 52, and RN cell 52-1, respectively. MeNB10, LPN20, and RN20-1 use the system radio | wireless resource 40 in order to communicate user data with each node.

  Assume that the exemplary configurations of MeNB10, LPN20, and UEs such as MeNB-UE 30A, LPN-UE 30B, and RN-UE 30B-1 are the same as those disclosed above in FIGS. 2, 3, and 4, respectively. For this reason, those descriptions are omitted.

  Assume that the exemplary configuration of RN 20-1 is similar to the configuration of LPN 20 as disclosed above in FIG. However, the communication unit 203 of the RN 20-1 has the same function as the communication unit 203 of the LPN 20 in FIG. 3, but is connected to the MeNB 10 instead of the core network. Therefore, when referring to the configuration of the RN 20-1, the subscript “-1” is added to each reference symbol in FIG. 3 to add the wireless communication unit 201-1, the reception data processor 202-1 and the communication unit 203-. 1, a transmission data processor 204-1, a scheduler 205-1, a memory 206-1, and a resource setting controller 207-1.

  Assume an exemplary system radio resource 40 as shown in FIG. Assume that the system radio resource allocation as shown in FIG. 5 is set in advance in the MeNB 10. MeNB10 is comprised so that the 1st resource part 41 for transmitting user data to MeNB-UE30A and the 2nd resource part 42 for transmitting user data to RN20-1 may be allocated. In LPN 20, it is assumed that the set radio link parameter of the system radio resource is transmission power.

4.2) Operation FIG. 14 shows an exemplary sequence diagram of the second exemplary embodiment according to the above assumptions. Since the operation steps of the LPN 20 in this embodiment are the same as steps S1101 to S1108 of the first exemplary embodiment in FIG. 6, the same reference numerals are used in FIG.

  With reference to FIG. 14, the steps of the operation of the MeNB 10 and the RN 20-1 will be described below. In steps S1501 and S1502, the system resource allocation information in the MeNB 10 as described above is stored in the memory 106 of the MeNB 10 and the memory 206-1 of the RN 20-1.

  In the time index corresponding to the first resource part, the scheduler 105 of the MeNB 10 uses the first resource part to transmit user data to the MeNB-UE 30A based on the system resource allocation information stored in the memory 106. Assign (step S1503). Further, the scheduler 205-1 of the RN 20-1 has the same function as the scheduler 205 of the LPN 20 in FIG. 3, and based on the system resource allocation information stored in the memory 206-1, sends the user to the RN-UE 30B-1. A first resource portion is allocated to transmit data (step S1504). And MeNB10 and RN20-1 transmit user data to MeNB-UE30A (step S1505) and RN-UE30B-1 (step S1506), respectively.

  On the other hand, in the time index corresponding to the second resource part, the scheduler 105 of the MeNB 10 allocates the second resource part to transmit user data to the RN 20-1 (step S1507). And MeNB10 transmits user data to RN20-1 (step S1508).

  In FIG. 15, it is assumed that the memory 106 has already stored the system resource allocation information in the MeNB 10 as described above. In step S1601, the scheduler 105 determines whether it is the start of a new time index for user data transmission. If it is not yet the time (No in S1601), the scheduler 105 repeats Step S1601. If it is that time (Yes in S1601), the scheduler 105 reads the system resource allocation information in the MeNB from the memory 106 (Step S1602). Then, the scheduler 105 determines to which part of the radio resource the current time index corresponds (step S1603). When the current time index corresponds to the first resource part (the first resource part in S1603), the scheduler 105 allocates the first resource part to transmit user data to the MeNB-UE 30A (step S1604). . And user data are transmitted to MeNB-UE30A through the radio | wireless communication part 101 (step S1605). On the other hand, if the current time index corresponds to the second resource part (second resource part of S1603), the scheduler 105 allocates the second resource part to transmit user data to the RN 20-1 (step S1606). Then, the user data is transmitted to the RN 20-1 through the wireless communication unit 101 (step S1607). After transmission to MeNB-UE 30A (step S1605) or RN 20-1 (step S1607), the process returns to step S1601.

  In FIG. 16, it is assumed that the memory 206-1 has already stored the system resource allocation information in the MeNB 10 as described above. In step S1701, the scheduler 205-1 determines whether it is the start of a new time index for user data transmission. If it is not yet the time (No in S1701), the scheduler 205-1 repeats step S1701. When it is that time (Yes in S1701), the scheduler 205-1 reads the system resource allocation information in the MeNB from the memory 206-1 (step S1702). Then, the scheduler 205-1 determines to which part of the radio resource the current time index corresponds (step S1703). If the current time index corresponds to the first resource part (first resource part of S1703), the scheduler 205-1 assigns the first resource part to transmit user data to the RN-UE 30B-1. (Step S1704). And user data are transmitted to RN-UE30B-1 through the radio | wireless communication part 201-1 (step S1705). The wireless communication unit 201-1 has the same function as the wireless communication unit 201 of the LPN 20 in FIG. On the other hand, when the current time index corresponds to the second resource part (second resource part of S1703), the scheduler 205-1 receives the user data transmitted from the MeNB 10 (step S1706). After transmission (step S1705) or reception (step S1706), the process returns to step S1701.

  Since the operation of the UE as shown in FIG. 4 is general knowledge of those skilled in the art, description thereof is omitted.

  The system radio resource allocation in the MeNB as described above is shown for the purpose of explanation, and the present embodiment is not limited to the method. As another example, if the LPN 20 is also another RN different from the RN 20-1, the MeNB 10 allocates a different part of the second resource part to transmit user data to the LPN 20 and the RN 20-1. Can do. In this case, in order to make the LPN 20 as effective as the above example, in addition to setting the transmission power, the LPN 20 excludes the part for itself as a part allocated for transmitting user data to the LPN-UE 30B. A portion for RN20-1 can be included.

  Further, instead of or in addition to the transmission power, the LPN 20 determines the ratio of resources allocated to transmit user data to the LPN-UE 30B relative to system radio resources, as disclosed in the first exemplary embodiment. It is also possible to set.

4.3) Effect As described above, according to the resource configuration according to the present embodiment, when MeNB 10 is transmitting user data to RN 20-1, LPN 20 transmits its own user data to LPN-UE 30B. In addition to increasing the transmission power, the RN 20-1 can transmit user data to the RN-UE 30B-1 simultaneously with the MeNB 10 and the LPN 20. Thereby, the throughput performance of the entire system including the MeNB 10, LPN 20, and RN 20-1 is further improved as compared with the first exemplary embodiment without causing additional interference to the MeNB-UE 30A.

5. Fourth Exemplary Embodiment In the second exemplary embodiment, the case where the LPN 20 controls the transmission power based on the system resource allocation information in the MeNB 10 is shown. In the fourth exemplary embodiment, the LPN 20 The case where transmission power is controlled based on the system resource allocation information transmitted by MeNB10 is shown. Details of this embodiment are described below.

5.1) System Referring to FIG. 17, the communication system includes a first base station (MeNB) 10, a second base station (LPN) 20, and a terminal (MeNB-UE) connected to the first base station. ) 30A, and a terminal (LPN-UE) 30B connected to the second base station. The MeNB 10 and the LPN 20 generate radio coverage of the MeNB cell 51 and the LPN cell 52, respectively. MeNB 10 and LPN 20 use system radio resources 40 to communicate user data with MeNB-UE 30A and LPN-UE 30B, respectively. The resource allocation information link RL is used to transmit system resource allocation information in the MeNB 10 to the LPN 20.

  Assume that the exemplary configurations of UEs such as MeNB 10, LPN 20, and MeNB-UE 30A and LPN-UE 30B are the same as those disclosed above in FIG. 2, FIG. 3, and FIG. 4, respectively. For this reason, those descriptions are omitted. Assume an exemplary configuration of system radio resources 40 as shown in FIG. For this reason, those descriptions are omitted.

  In the MeNB, it is assumed that the system radio resource allocation as disclosed in FIG. 5 is set in advance by the network operator. The MeNB 10 allocates a first resource part 41 for transmitting user data to the MeNB-UE 30A and a second resource part 42 for restricted use for transmitting control channels and / or reference signals. Composed. It is also assumed that the system resource allocation information set in advance by the network operator is already stored in the memory 106 of the MeNB 10. In LPN 20, it is assumed that the set radio link parameter of the system radio resource is transmission power.

5.2) Operation Referring to FIG. 18, the MeNB 10 transmits system resource allocation information to the LPN 20 through the resource allocation information link RL. After receiving the system resource allocation information from the MeNB 10, the LPN 20 stores the system resource allocation information in the memory 206 (step S1802). Thereafter, the operation steps of the LPN are the same as steps S1102 to S1108 of the first exemplary embodiment in FIG. Also, the steps of the operation of the MeNB are the same as steps S1302 to S1304 of the second exemplary embodiment in FIG. For this reason, those descriptions are omitted.

  FIG. 19 shows an exemplary control flow in the MeNB 10 for transmitting user data to the MeNB-UE 30A. It is assumed that the memory 106 has already stored the system resource allocation information as described above. In step S1901, the MeNB 10 transmits system resource allocation information to the LPN 20 through the resource allocation information link RL. Thereafter, the operation steps of the MeNB are the same as steps S1401 to S1406 of the second exemplary embodiment in FIG. For this reason, those descriptions are omitted.

  Referring to FIG. 20, in step S2001, the scheduler 205 receives the system resource allocation information as described above from the MeNB 10. Then, the scheduler 205 transfers the received system resource allocation information to be stored in the memory 206 through the resource setting controller 207 (step S2002). Thereafter, the operation steps of the LPN are the same as steps S1201 to S1208 of the first exemplary embodiment in FIG. For this reason, those descriptions are omitted. The exemplary data reception operation of the UE is also omitted because it is general knowledge of those skilled in the art.

  The above method for transmitting the system resource allocation information to the LPN 20 is shown for the purpose of explanation, and the present embodiment is not limited to this method. As another example, the system resource allocation information can be transmitted to the LPN 20 through an upper layer network connected to both the MeNB 10 and the LPN 20 such as a core network.

  Furthermore, the method of transmitting the system resource allocation information disclosed in this embodiment to the LPN 20 is considered to be effective for all of the preceding exemplary embodiments described above.

5.3) Effect As described above, according to the configuration of the present embodiment, the MeNB 10 can update the system resource allocation information stored in the LPN 20 when there is a change due to a request. For this reason, in addition to increasing its own transmission power for the LPN 20 to transmit user data to the LPN-UE 30B when the MeNB 10 restricts its transmission process, the LPN 20 transmits the allocation change in the MeNB 10 The power can be controlled adaptively. Therefore, the robustness with respect to the change of the system resource allocation information in the MeNB 10 can be achieved by improving the throughput performance of the LPN 20 without causing additional interference to the MeNB-UE 30A.

6). 5th exemplary embodiment In 1st exemplary embodiment, LPN20 showed the case where transmission power was set based on the system resource allocation information in MeNB10, but in 5th exemplary embodiment, 1st In addition to the process in the exemplary embodiment, the case where the LPN 20 transmits the set transmission power information to the LPN-UE 30B is shown. Details of this embodiment are described below. Since the operation related to the setting of the transmission power of the LPN 20 in this embodiment is the same as that of the first exemplary embodiment disclosed in FIGS. 1 to 7, the description thereof is omitted.

  After the transmission power of the LPN 20 is set, the set transmission power information is transmitted from the LPN 20 to the LPN-UE 30B through the wireless communication unit 201. After receiving this information, the reception data processor 302 in the LPN-UE 30B stores it in the memory 303. Based on the set transmission power information, the reception data processor 302 can set a power offset value for calculating RSRP or RSRQ. RSRP or RSRQ indicates the quality of the radio link between the LPN 20 and the LPN-UE 30B.

  Since the operation steps in the LPN 20 and the LPN-UE 30B as described above are general knowledge of those skilled in the art, their sequence diagrams and flowcharts are omitted. Furthermore, the method of transmitting the set transmission power information disclosed in this embodiment from the LPN 20 to the LPN-UE 30B is considered to be effective for all of the preceding exemplary embodiments described above.

  As described above, according to the configuration according to the present embodiment, when MeNB 10 allocates the second resource part for a function other than transmitting user data to MeNB-UE 30A, LPN 20 assigns user data to LPN-UE 30B. In addition to increasing its own transmit power for transmitting, the LPN-UE 30B may have an accurate value for the radio link quality indicator. For this reason, in addition to improving the throughput performance of the LPN 20 without causing additional interference to the MeNB-UE 30A, an accurate operation of the LPN-UE 30B can be achieved by handover determination or the like.

7). Appendices All or part of the exemplary embodiments disclosed above can be described as, but not limited to, the following appendices.
(Appendix 1)
A base station located within a first radio coverage of a first base station in a communication system, the base station having a lower transmission power than the first base station;
A storage unit for storing system resource allocation information related to system radio resources divided into a first part and a second part, wherein the first part is a terminal connected to the first base station; A storage unit assigned to user data communication of the first base station, and the second part assigned to at least one function of the first base station other than the user data communication;
And a controller that changes a setting of at least one radio link parameter of the first part and the second part assigned to user data transmission of the base station according to the system resource assignment information. Bureau.
(Appendix 2)
The controller sets, as radio link parameters, transmission power and / or a ratio of resources for user data transmission of the base station, and the ratio of the resources is the user data of the base station with respect to the amount of the system radio resource. The base station according to appendix 1, wherein the base station is a ratio of the amount of resources used for transmission.
(Appendix 3)
The controller is configured to set the transmission power and / or the resource ratio when the second portion is allocated to be larger than when the first portion is allocated. 2. The base station according to 2.
(Appendix 4)
The controller controls the transmission unit to transmit information related to two transmission powers when the first and second parts are respectively allocated to a terminal connected to the base station. The base station according to Appendix 3.
(Appendix 5)
Any one of appendices 1 to 4, wherein the system resource allocation information is received from the first base station or an upper layer network entity connecting the base station and the first base station. The base station according to claim 1.
(Appendix 6)
In a base station having radio coverage where a low power node is located, the low power node has a lower transmit power than the base station,
A storage unit for storing system resource allocation information related to system radio resources divided into a first part and a second part;
A user data communication function for transmitting user data to a terminal connected to the base station when the first part is assigned, and the user data when the second part is assigned A scheduler that executes at least one function other than communication,
The low power node changes a setting of at least one radio link parameter of the first part and the second part allocated to user data transmission of the low power node according to the system resource allocation information. Base station.
(Appendix 7)
The base station according to appendix 6, wherein the scheduler transmits a control channel and / or a reference signal to a terminal connected to the base station when the second portion is allocated.
(Appendix 8)
The low power node sets transmission power and / or a resource ratio for user data transmission of the low power node as a radio link parameter, and the resource ratio is the low power with respect to the amount of the system radio resource. The base station according to appendix 6 or 7, characterized in that it is a ratio of the amount of resources used for user data transmission of a node.
(Appendix 9)
The low power node is configured to set the transmission power and / or the resource ratio when the second part is allocated to be larger than when the first part is allocated. The base station according to appendix 8.
(Appendix 10)
The low power node controls a transmission unit to transmit information related to two transmission powers when the first and second parts are respectively assigned to a terminal connected to the low power node. The base station according to appendix 9, wherein
(Appendix 11)
The scheduler transmits user data to a relay node connected to the base station using the resource of the second part when the second part is allocated, and the relay node 11. The base station according to any one of appendices 6 to 10, wherein user data is transmitted to a terminal connected to the relay node.
(Appendix 12)
A first base station;
At least one second base station within radio coverage of the first base station and having a lower transmission power than the first base station;
In a communication system comprising at least one terminal connected to each of the first and second base stations,
The first base station is
A first storage unit that stores system resource allocation information related to system radio resources divided into a first part and a second part;
When a user data communication function for transmitting user data to a terminal connected to the first base station is executed when the first part is assigned, and when the second part is assigned A scheduler that executes at least one function other than the user data communication,
The second base station is
A second storage unit for storing the system resource allocation information, wherein the first part is allocated to user data communication of the first base station with a terminal connected to the first base station; The second portion is assigned to at least one function of the first base station other than the user data communication, and a second storage unit;
A controller for changing a setting of at least one radio link parameter of the first part and the second part assigned to user data transmission of the second base station according to the system resource assignment information. A communication system.
(Appendix 13)
In a radio resource setting method in a base station arranged in a first radio coverage of a first base station in a communication system, the base station has a lower transmission power than the first base station, the method But,
Storing system resource allocation information related to system radio resources divided into a first part and a second part, wherein the first part is connected to a terminal connected to the first base station. Allocating to user data communication of the first base station and storing the second portion to at least one function of the first base station other than the user data communication;
Changing the setting of at least one radio link parameter of the first part and the second part assigned to user data transmission of the base station according to the system resource assignment information. Resource setting method.
(Appendix 14)
A transmission power and / or a ratio of resources for user data transmission of the base station is set as a radio link parameter, and the ratio of the resources is used for user data transmission of the base station with respect to the amount of the system radio resource. 14. The method according to appendix 13, wherein the method is a ratio of the amount of resources to be processed.
(Appendix 15)
15. The method of claim 14, wherein the transmission power and / or the resource ratio when the second part is allocated is greater than when the first part is allocated.
(Appendix 16)
The method according to supplementary note 15, wherein information related to two transmission powers when the first and second parts are respectively allocated is transmitted to a terminal connected to the base station.
(Appendix 17)
Any one of supplementary notes 13 to 16, wherein the system resource allocation information is received from the first base station or an upper layer network entity connecting the base station and the first base station. The method according to claim 1.
(Appendix 18)
In a radio resource setting method in a base station having radio coverage in which a low power node is arranged, the low power node has lower transmission power than the base station, and the method includes:
Storing system resource allocation information related to system radio resources divided into a first part and a second part;
Executing a user data communication function for transmitting user data to a terminal connected to the base station when the first portion is allocated;
Performing at least one function other than the user data communication when the second part is allocated, and
The low power node changes a setting of at least one radio link parameter of the first part and the second part allocated to user data transmission of the low power node according to the system resource allocation information. How to set up the radio resources.
(Appendix 19)
The method according to appendix 18, wherein a control channel and / or a reference signal is transmitted to a terminal connected to the base station when the second part is allocated.
(Appendix 20)
The low power node sets transmission power and / or a resource ratio for user data transmission of the low power node as a radio link parameter, and the resource ratio is the low power with respect to the amount of the system radio resource. 20. The method according to appendix 18 or 19, characterized in that it is a ratio of the amount of resources used for user data transmission of the node.
(Appendix 21)
The low power node is configured to set the transmission power and / or the resource ratio when the second part is allocated to be larger than when the first part is allocated. The method according to appendix 20.
(Appendix 22)
The low power node controls a transmission unit to transmit information related to two transmission powers when the first and second parts are respectively assigned to a terminal connected to the low power node. The method according to supplementary note 21, characterized in that:
(Appendix 23)
When the second part is allocated, the base station transmits user data to a relay node connected to the base station using the resource of the second part, and the relay node 23. The method according to any one of appendices 18 to 22, wherein user data is transmitted to a terminal connected to the relay node.
(Appendix 24)
In a storage device storing a program instructing a program-controlled processor to control radio resources in a base station located within a first radio coverage of a first base station in a communication system, the base station Having a lower transmission power than the first base station, the program comprising:
Storing system resource allocation information related to system radio resources divided into a first part and a second part, wherein the first part is connected to a terminal connected to the first base station. Allocating to user data communication of the first base station and storing the second portion to at least one function of the first base station other than the user data communication;
Changing the setting of at least one radio link parameter of the first part and the second part assigned to the user data transmission of the base station according to the system resource assignment information. apparatus.
(Appendix 25)
A transmission power and / or a ratio of resources for user data transmission of the base station is set as a radio link parameter, and the ratio of the resources is used for the user data transmission of the base station to the amount of the system radio resources 25. The storage device according to appendix 24, wherein the storage device is a ratio of the amount of resources to be processed.
(Appendix 26)
26. The storage device according to appendix 25, wherein a ratio of the transmission power and / or the resource when the second part is allocated is larger than that when the first part is allocated.
(Appendix 27)
27. The storage device according to appendix 26, wherein information related to two transmission powers when the first and second portions are respectively allocated is transmitted to a terminal connected to the base station.
(Appendix 28)
Any one of appendices 24 to 27, wherein the system resource allocation information is received from the first base station or an upper layer network entity that connects the base station and the first base station. The storage device according to claim 1.
(Appendix 29)
In a storage device storing a program instructing a program-controlled processor to control radio resources in a base station having radio coverage where a low power node is located, the low power node transmits lower than the base station Have power and the program
Storing system resource allocation information related to system radio resources divided into a first part and a second part;
Executing a user data communication function for transmitting user data to a terminal connected to the base station when the first portion is allocated;
Performing at least one function other than the user data communication when the second part is allocated, and
The low power node changes a setting of at least one radio link parameter of the first part and the second part allocated to user data transmission of the low power node according to the system resource allocation information. Storage device.
(Appendix 30)
29. The storage device according to appendix 29, wherein when the second part is allocated, a control channel and / or a reference signal is transmitted to a terminal connected to the base station.
(Appendix 31)
The low power node sets transmission power and / or a resource ratio for user data transmission of the low power node as a radio link parameter, and the resource ratio is the low power with respect to the amount of the system radio resource. 31. The storage device according to appendix 29 or 30, wherein the storage device is a ratio of the amount of resources used for user data transmission of a node.
(Appendix 32)
The low power node is configured to set the transmission power and / or the resource ratio when the second part is allocated to be larger than when the first part is allocated. The storage device according to attachment 31.
(Appendix 33)
The low power node controls a transmission unit to transmit information related to two transmission powers when the first and second parts are respectively assigned to a terminal connected to the low power node. The storage device according to appendix 32, wherein:
(Appendix 34)
When the second part is allocated, the base station transmits user data to a relay node connected to the base station using the resource of the second part, and the relay node 34. The storage device according to any one of appendices 29 to 33, wherein user data is transmitted to a terminal connected to the relay node.

  The present invention is applicable to a heterogeneous cellular network in which heterogeneous base stations are deployed, such as a low power node embedded in a macro cellular network, and particularly to a mobile communication system provided in an area including a narrow passage. .

10 Base station (MeNB)
20 Base station (low power node)
20-1 Base station (relay node)
30, 30-1, 30-2 User equipment (UE)
40 System radio resource 51 MeNB radio coverage 52 LPN radio coverage

Claims (9)

A base station located within a first radio coverage of a first base station in a communication system, the base station having a lower transmission power than the first base station;
Storage means for storing in advance system resource allocation information related to system radio resources divided into a first part and a second part at least in the time domain ;
Control means for changing the setting of the transmission power of the base station between the first part and the second part based on the system resource allocation information ;
With
The first part and the second part are usable in both the base station and the first base station, and the first base station is connected to the first base station; Using the first portion for user data communication and using the second portion for at least one function of the first base station other than the user data communication. base station. Wherein, the base station according to claim 1, characterized in that to set to be larger than when the transmission power when using the second portion using said first portion . Said control means, said information relating to two transmission power when using the first portion and the second portion, respectively, controls the transmission unit to transmit to the terminals connected to the base station The base station according to claim 2 , wherein: In a base station having radio coverage where a low power node is located, the low power node has a lower transmit power than the base station,
Storage means for storing in advance system resource allocation information related to system radio resources divided into a first part and a second part at least in the time domain ;
Performing user data communication function for transmitting user data to a terminal connected to the base station when using the first part and using the second part , the user data A scheduler that executes at least one function other than communication,
The first part and the second part are usable in both the low power node and the base station;
The base station , wherein the low power node changes a transmission power setting of the low power node between the first part and the second part based on the system resource allocation information . The base station according to claim 4 , wherein the scheduler transmits a control channel and / or a reference signal to a terminal connected to the base station when the second part is used. . The scheduler, when using the second portion, by using the resources of the second part transmits the user data to the connected relay node to the base station, said relay node, said The base station according to claim 4 or 5 , wherein user data is transmitted to a terminal connected to the relay node. A first base station;
At least one second base station within radio coverage of the first base station and having a lower transmission power than the first base station;
In a communication system comprising at least one terminal connected to each of the first and second base stations,
The first base station is
A first storage unit that stores system resource allocation information related to system radio resources divided into a first part and a second part at least in the time domain ;
When the terminal connected to the first base station performs user data communication function for transmitting user data, using the second portion when using the first portion A scheduler that executes at least one function other than the user data communication,
The second base station is
A second storage unit for storing the system resource allocation information in advance ;
A communication system comprising: control means for changing a setting of transmission power of the base station between the first part and the second part based on the system resource allocation information . In a radio resource setting method in a base station arranged in a first radio coverage of a first base station in a communication system, the base station has a lower transmission power than the first base station, the method But,
Storing in advance system resource allocation information related to system radio resources divided into a first part and a second part at least in the time domain ;
Changing the transmission power setting of the base station between the first part and the second part based on the system resource allocation information ;
Have
The first part and the second part are usable in both the base station and the first base station, and the first base station is connected to the first base station; Using the first portion for user data communication and using the second portion for at least one function of the first base station other than the user data communication. How to set radio resources. In a radio resource setting method in a base station having radio coverage in which a low power node is arranged, the low power node has lower transmission power than the base station, and the method includes:
Storing system resource allocation information related to system radio resources divided into a first part and a second part at least in the time domain ;
Executing a user data communication function for transmitting user data to a terminal connected to the base station when using the first portion;
Performing at least one function other than the user data communication when using the second part,
The first part and the second part are usable in both the low power node and the base station;
The low power node changes the transmission power setting of the low power node between the first part and the second part based on the system resource allocation information . Setting method.

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