JP2015231097A - User terminal, radio base station, and radio communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve wide coverage while reducing collision of D2D signals.SOLUTION: A user terminal according to one aspect of the present invention includes: a division unit for dividing a D2D resource group to which a D2D signal can be allocated into a plurality of sub-resource groups; a resource position determination unit for determining a resource position where a D2D signal is allocated in at least one sub-resource group on the basis of a first hopping pattern; and a transmission unit for performing repetitive transmission by mapping the D2D signal to the resource position.

Description

  The present invention relates to a user terminal, a radio base station, and a radio communication method in a next generation mobile communication system.

  In LTE (Long Term Evolution) and LTE successor systems (for example, LTE-A (LTE Advanced), FRA (Future Radio Access), 4G, etc.), user terminals communicate directly with each other without a radio base station. D2D (Device to Device) technology to be performed has been studied (for example, Non-Patent Document 1).

  D2D includes D2D discovery (also called D2D discovery, also called D2D discovery) for finding other user terminals that can communicate, and D2D communication (D2D direct communication, D2D communication, direct communication between terminals, etc.) for direct communication between terminals Also called). Hereinafter, when D2D communication, D2D discovery, and the like are not particularly distinguished, they are simply referred to as D2D. A signal transmitted and received in D2D is referred to as a D2D signal.

  As a resource for D2D signals, it is considered that a network allocates part of uplink resources to each user terminal in a semi-static manner. For example, the user terminal transmits a discovery signal (discovery signal) using the allocated D2D discovery resource. Further, the user terminal can find another user terminal capable of communication by receiving the discovery signal transmitted from the other user terminal using the D2D discovery resource.

“Key drivers for LTE success: Services Evolution”, September 2011, 3GPP, Internet URL: http://www.3gpp.org/ftp/Information/presentations/presentations_2011/2011_09_LTE_Asia/2011_LTE-Asia_3GPP_Service_evolution.pdf

  In D2D, since transmission and reception are performed with one uplink time / frequency resource, there is a restriction of half duplex that reception is not possible during transmission. For this reason, for each D2D signal, a technique for reducing the collision as much as possible is required. In addition, while the transmission power of user terminals is limited, it is required to realize wider coverage for each D2D signal.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a user terminal, a radio base station, and a radio communication method capable of realizing wide coverage while reducing collision of D2D signals. To do.

  The user terminal which concerns on 1 aspect of this invention is a resource position which allocates a D2D signal within the division part which divides | segments the D2D resource group which can allocate D2D signal into a some sub resource group, and at least one said sub resource group Is determined based on a first hopping pattern, and a transmission unit that repeats transmission by mapping a D2D signal to the resource position.

  According to the present invention, it is possible to realize a wide coverage while reducing the collision of D2D signals.

It is a conceptual diagram of D2D discovery resource. In type 2B discovery, it is a figure which shows an example in the case of hopping a transmission resource between discovery periods. It is a conceptual diagram of a D2D communication resource. It is explanatory drawing of the resource determination method of D2D which concerns on 1 aspect of this invention. It is a figure which shows an example of the repetition transmission and hopping of the D2D signal which concern on one Embodiment of this invention. It is a figure which shows an example of the repetition transmission and hopping of type 2A / 2B discovery which concern on one Embodiment of this invention. It is a figure which shows an example of the repetition transmission and hopping of type 2A / 2B discovery which concern on one Embodiment of this invention. It is a figure which shows an example of the repetition transmission and hopping of type 2A / 2B discovery which concern on one Embodiment of this invention. It is a figure which shows an example of the repetition transmission and hopping of type 2A / 2B discovery which concern on one Embodiment of this invention. It is a figure which shows an example of the repetition transmission and hopping of type 2A / 2B discovery which concern on one Embodiment of this invention. It is a figure which shows an example of the repetition transmission and hopping of type 2A / 2B discovery which concern on one Embodiment of this invention. It is a figure which shows an example of the repetition transmission and hopping of type 2A / 2B discovery which concern on one Embodiment of this invention. It is a figure which shows an example of the repetition transmission and hopping of type 1 discovery which concern on one Embodiment of this invention. It is a figure which shows an example of repeated transmission and hopping of SA in D2D communication which concerns on one Embodiment of this invention. It is a figure which shows an example of repeated transmission and hopping of SA in D2D communication which concerns on one Embodiment of this invention. It is a figure which shows an example of the repeated transmission and hopping of D2D data in D2D communication which concern on one Embodiment of this invention. It is a figure which shows an example of schematic structure of the radio | wireless communications system which concerns on one Embodiment of this invention. It is a figure which shows an example of the whole structure of the wireless base station which concerns on one Embodiment of this invention. It is a figure which shows an example of a function structure of the wireless base station which concerns on one Embodiment of this invention. It is a figure which shows an example of the whole structure of the user terminal which concerns on one Embodiment of this invention. It is a figure which shows an example of a function structure of the user terminal which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, resource allocation of D2D signals will be described.

  A user terminal capable of transmitting and receiving D2D signals is set with a time / frequency resource group for transmitting and receiving D2D signals (hereinafter also referred to as D2D resource group). The D2D resource group refers to a radio resource area to which a D2D signal can be assigned. The D2D resource group may be set in the user terminal by being notified of information related to the D2D resource group from the radio base station or another user terminal, or may be set in advance.

  As the D2D resource group, use of a part of uplink resources of normal cellular communication (WAN) is being studied. In order to avoid interference, the WAN signal and the D2D signal are time division multiplexed (TDM) or frequency division multiplexed (FDM).

  The user terminal transmits a D2D signal using a part of the resources of the D2D resource group. For example, a user terminal finds another D2D terminal by receiving a discovery signal (discovery signal) transmitted from another user terminal within the D2D resource group (D2D discovery). The user terminal directly communicates with other user terminals within the D2D resource group (D2D communication).

  In D2D discovery, it is considered that a resource group for discovery signal transmission is periodically allocated. D2D discovery is classified into type 1 (Type 1) and type 2 (Type 2) according to a resource allocation method for transmitting a discovery signal. In type 1, the resource of the discovery signal is determined to be non-unique for each user terminal, and in type 2, the resource is determined to be unique for each user terminal.

  In type 1 discovery, each user terminal selects a transmission resource at random or in accordance with a predetermined rule, so there is a possibility that the transmission resource may collide between user terminals. For this reason, type 1 discovery is also called a collision type.

  In type 2 discovery, each user terminal transmits a discovery signal using a D2D resource designated from the network, so that collision of transmission resources between user terminals can be avoided. Therefore, type 2 discovery is also called non-collision type.

  Type 2 is further classified into two types (types 2A and 2B) according to the D2D resource notification method. In type 2A, dynamic scheduling is performed using PDCCH and / or EPDCCH (hereinafter also referred to as (E) PDCCH). In type 2B, semi-persistent scheduling is performed using higher layer signaling (for example, RRC signaling).

  FIG. 1 is a conceptual diagram of a D2D discovery resource. 1A, 1B, and 1C show resource allocation in type 1, 2A, and 2B D2D discovery, respectively. In D2D discovery, a D2D resource group for assigning discovery signals in a predetermined period (also referred to as a discovery period) is set to be semi-static by the network. Similarly, in FIG. 2 to FIG. 16, D2D resource allocation for a predetermined user terminal is also shown. In each figure, the horizontal axis represents the resource time direction, and the vertical axis represents the resource frequency direction. 1 to 16 show an example in which the WAN signal and the D2D signal are TDM, but the embodiment of the present invention is not limited to this.

  As shown in FIG. 1A, in type 1 discovery, a user terminal autonomously determines a transmission resource of its own terminal from a D2D resource group notified from a network, either randomly or according to a predetermined rule. The type 1 D2D resource group may be referred to as a type 1 resource group, a D2D resource pool (type 1), or the like.

  As shown in FIG. 1B, in type 2A discovery, a user terminal dynamically uses a D2D resource notified from the network by (E) PDCCH as a transmission resource. As shown in FIG. 1C, in type 2B discovery, the user terminal uses the D2D resource notified from the network by higher layer signaling semi-fixedly as a transmission resource for each period. A type 2 D2D resource group may be referred to as a type 2 resource group.

  Since the user terminal performs transmission and reception with one uplink time / frequency resource, the user terminal is subjected to a half duplex restriction that reception is not possible during transmission. For this reason, a user terminal cannot detect a D2D signal transmitted by another user terminal if a transmission resource for the D2D signal is allocated at the same time (for example, the same subframe). This problem becomes noticeable in Type 2B discovery where D2D resource allocation is constant over a relatively long period of time.

  Therefore, in type 2B discovery, it is considered to hop transmission resources between discovery periods. FIG. 2 is a diagram illustrating an example of hopping transmission resources between discovery periods in type 2B discovery. In FIG. 2, in a predetermined D2D resource group, D2D resources are semi-persistently scheduled. On the other hand, in the subsequent discovery cycle, the resource location obtained by hopping the D2D resource location used in the preceding discovery cycle in accordance with a predetermined rule is used for D2D signal allocation.

  Thus, by determining the allocation of D2D resources by hopping, it is possible to randomize the collision of D2D transmission / reception. In addition, interference randomization to the cellular, frequency diversity effect, and the like can be realized.

  On the other hand, in D2D communication, a user terminal notifies information related to a resource position for D2D data transmission. The information is also referred to as scheduling assignment (SA), and is notified by, for example, a user terminal that transmits D2D data. It is considered that a resource group for SA transmission is allocated periodically or under a predetermined condition, and information on the resource group is assumed to be notified from the network to the user terminal. In addition, after transmitting the SA, the user terminal transmits D2D data using the data transmission resource notified by the SA.

  In addition, you may perform transmission of SA and D2D data with the resource based on the predetermined scheduling grant notified by (E) PDCCH. In addition, information on the SA transmission resource group and / or the D2D data transmission resource group may be included in the scheduling grant and notified.

  D2D communication is classified into mode 1 (Mode 1) and mode 2 (Mode 2) according to the allocation method of resources for transmitting SA and data, as in the D2D discovery type. In mode 1, the user terminal uses SA and data resources notified from the network. That is, in mode 1, dynamic scheduling is performed using (E) PDCCH. In mode 2, the user terminal uses SA and data resources autonomously determined from a predetermined resource group (resource pool). The D2D resource group for SA may be called an SA resource pool, and the D2D resource group for D2D data may be called a D2D data resource pool.

  FIG. 3 is a conceptual diagram of D2D communication resources. FIGS. 3A and 3B show assignments in D2D communication in modes 1 and 2, respectively. In the example of FIG. 3, the D2D resource group for allocating SA at a predetermined period or a predetermined timing is set to be semi-static by the network.

  As shown in FIG. 3A, in mode 1 communication, the user terminal uses the D2D resource notified from the network by (E) PDCCH as a transmission resource.

  As illustrated in FIG. 3B, in mode 2 communication, the user terminal autonomously determines a transmission resource of the terminal itself from the D2D resource group notified from the network, either randomly or according to a predetermined rule.

  As described above, in D2D, various resource allocation methods are being studied according to transmission signals. On the other hand, it is required to realize wider coverage for each D2D signal while the transmission power of the user terminal is limited. Further, there is a demand for a technique for reducing collision as much as possible for each D2D signal.

  In order to solve these problems, the present inventors have conceived that a D2D signal is repeatedly transmitted within a D2D resource group. Furthermore, the hopping of type 2B discovery was further developed, and the idea of hopping D2D resources used for the repeated transmission according to a predetermined hopping pattern was conceived.

  According to these configurations, the user terminal that has received the repeatedly transmitted D2D signal can obtain the coverage expansion effect by combining and receiving the same D2D signal. Further, in D2D, it is possible to enjoy the collision randomization, the frequency diversity effect, the interference randomization effect on cellular, and the like as described above for type 2B discovery.

  Further, by using a common hopping pattern (shared hopping pattern) for D2D discovery signals between different types and / or D2D communication signals between different modes, the resource location of the D2D signal in various D2D communication formats It is possible to reduce the amount of information related to signaling for grasping and simplify the reception operation.

  Hereinafter, the D2D resource determination method according to the present invention will be described in detail. The method includes division of a D2D resource group, repeated transmission of the same D2D signal between the divided sub-resource groups, and hopping of D2D signal allocation resources between the divided sub-resources. FIG. 4 is an explanatory diagram of a D2D resource determination method according to an aspect of the present invention. In the following example, a case is described in which the number of repeated transmissions (the number of retransmissions of the same D2D signal) is 3, but the present invention is not limited to this. Also, the same RV (Redundancy Version) may be used for the retransmitted signals, or different RVs may be used so that IR (Incremental Redundancy) synthesis can be performed.

(D2D resource group division)
First, the user terminal divides the D2D resource group into a plurality of sub-resource groups (FIG. 4A). Although FIG. 4A shows an example in which the D2D resource group is divided into three equal parts in the time direction, the present invention is not limited to this. For example, the division may be performed for either the time direction or the frequency direction, or a combination thereof. Moreover, although it is preferable that each sub-resource group is the same size, it may be a different size.

  In addition, in order for each user terminal to identify the transmission resource of the D2D signal within the divided sub resource group, information indicating the time and / or frequency resource of the sub resource group (hereinafter referred to as sub resource group information) is used. Also good. For example, the divided sub-resource group can be determined by any one of (1) to (5) below or a combination thereof.

  (1) As the sub resource group information, the time of the sub resource group and the position of the frequency resource (for example, the number of resource blocks and the time and / or frequency position at which the resource block starts) are used. In this case, each sub-resource group is determined using the resource position information.

  (2) The transmission resource pool (D2D resource group) and the number of sub resources (number of retransmissions) are used as the sub resource group information. In this case, the sub-resource group is determined by dividing the transmission resource pool in the frequency direction and / or the time direction by a predetermined method based on the number of sub-resources (number of retransmissions). For example, the transmission resource pool is equally divided (divided into equal intervals) by the number of sub-resources (number of retransmissions) to determine a sub-resource group.

  (3) A reception resource pool (D2D resource group) is used as the sub resource group information. In this case, the frequency resource of the sub resource group is determined based on the reception resource pool. For example, the frequency resource of the sub resource group may be regarded as the same as the frequency resource of the reception resource pool. In addition, when the information of the reception resource pool is separately signaled, it is not necessary to notify it as the sub resource group information again, and the amount of signaling can be reduced.

  (4) A fixed value (for example, resource block size) related to the frequency resource is used as the sub resource group information. In this case, the frequency resource of the sub resource group is determined based on the fixed value.

  (5) A fixed value (for example, the number of subframes) related to time resources is used as the subresource group information. In this case, the time resource of the sub-resource group is determined based on the fixed value.

  The sub-resource group information may be transmitted / received between user terminals, may be transmitted / received between the user terminal and the radio base station, or may be set in advance in the user terminal. For notification of sub-resource group information, higher layer signaling (including SIB and RRC), D2D synchronization channel (PD2DSCH: Physical D2D Synchronization Channel), and the like can be used.

  In addition, a network (for example, a radio base station) may notify the user terminal of information regarding which subresource group information is used to determine the divided subresource group. The user terminal can switch the determination of the division method of the D2D resource group based on the received information. For example, based on the information, the determination of the sub resource group can be switched from (1) to (2).

  Further, the D2D resource group and the sub resource group may be continuous in time and / or frequency, or may be discontinuous. In the case of discontinuity, a logical time / frequency index or resource index for the discontinuous resource may be used. As a result, discontinuous resource groups are virtually regarded as one continuous resource group, so that unified processing with continuous resource groups can be performed, and user terminal processing can be simplified. It becomes.

(D2D signal repetitive transmission and hopping)
The user terminal repeatedly transmits the same D2D signal in each of the plurality of sub-resource groups (FIG. 4B). However, the repeatedly transmitted D2D signal is hopped so as to use different resources among the divided sub-resource groups based on a predetermined hopping pattern and transmitted (FIG. 4C). For example, as shown in FIG. 4C, the resource for hopping between the sub-resource groups and transmitting the D2D signal is determined so that the relative resource position in each sub-resource group is different.

FIG. 5 is a diagram illustrating an example of repeated transmission and hopping of a D2D signal according to an embodiment of the present invention. FIG. 5 shows an example in which the D2D resource group in the T-th discovery cycle is divided into three sub-resource groups (hereinafter referred to as 1 ^st Tx, 2 ^nd Tx, and 3 ^rd Tx, respectively). . Transmission resource position of D2D signals 2 ^nd Tx ^is determined to resource location of the same D2D signal at ¹ st Tx (i.e., resource location within the previous sub-group of resources), and a predetermined hopping pattern, the . Further, the transmission resource position of the 3 ^rd Tx D2D signal is determined by the resource position of the same D2D signal at 2 ^nd Tx and a predetermined hopping pattern.

  According to this configuration, when the user terminal on the receiving side can recognize the resources of a plurality of D2D signals that are repeatedly transmitted, coverage expansion can be realized by combined reception. Such composite reception is possible even during the discovery period, but considering the length of the discovery period and the case where multiple periods are defined, a large buffer size is required. Reception is preferable from the viewpoint of terminal implementation. In addition, it is possible to suitably randomize subframes incapable of receiving a D2D signal due to a half duplex restriction that cannot be received during transmission by hopping.

  Note that the user terminal does not necessarily have to transmit a D2D signal in each sub-resource group. For example, in any sub-resource group, transmission of the D2D signal may be omitted (skipped), or reception of the D2D signal transmitted from another user terminal may be performed instead. Since the required quality of the D2D signal depends on the transmission content, the reception quality of the important D2D signal can be improved while avoiding excessive transmission quality by omitting such transmission. Omission of transmission of the D2D signal may be autonomously performed by the user terminal, or a part of the hopping pattern or an omission instruction may be notified from the network. In addition, it is possible to notify the user terminal receiving the D2D signal that transmission of the D2D signal is omitted using SA. As a result, it is possible to avoid performance degradation of combined reception.

  In the example of FIG. 5, a case where hopping is applied in a subframe group in a certain resource pool (D2D resource group) is shown, but the present invention is not limited to this. For example, hopping may be applied in subframe groups between different resource pools. In this case, the hopping pattern applied between resource pools may be the same as or different from the hopping pattern applied within the resource pool.

  Hereinafter, the D2D resource determination method illustrated in FIG. 4 will be specifically described for each type of D2D signal (for example, the type in D2D discovery and the mode in D2D communication).

(Determination of type 2A / 2B discovery resources)
In the resource determination of type 2A / 2B discovery, the transmission pattern of the discovery signal within one discovery period is determined so as to satisfy the following (a) and (b).

  (A) A discovery signal transmission subframe is divided by the number of repeated transmissions, and a predetermined D2D signal (repetition signal) is transmitted by each divided subresource group. Note that the number of retransmissions within one discovery cycle may be notified by higher layer signaling (including SIB and RRC), or may be notified implicitly from the number of sub-resources.

  (B) Resources for transmitting signals in the (K + 1) th sub-resource group ((K + 1) -th Tx) include resources for transmitting signals in the K-th sub-resource group (K-th Tx), and a resource determination function (For example, f (r)). Here, the resource determination function is also called a hopping pattern.

  By configuring in this way, it is possible to enable combined reception by the user terminal in the cell and / or another cell of the discovery signal repeatedly transmitted. In addition, by making f (r) common among cells, it is possible to synthesize discovery signals repeatedly transmitted to user terminals in adjacent cells without separately reporting the hopping pattern of each cell. .

  In this resource determination method, when there is a resource allocation (initial resource allocation) by (E) PDCCH (in the case of type 2A) or higher layer signaling (in the case of type 2B) from the network, This is used as a transmission resource for discovery signals in the first sub-resource group within the discovery period.

  On the other hand, after a transmission pattern within a certain discovery cycle is determined, if there is no resource reassignment or resource release instruction from the network, the first resource within the next discovery cycle is either You may determine by the hopping pattern by a combination.

  In the first method, a hopping pattern (for example, f (r)) within the discovery period is applied during the discovery period. According to this, combined reception during the discovery period is possible including user terminals of other cells. In the second method, a different hopping pattern (for example, a function g (r) different from f (r)) is applied to each cell. As a result, some user terminals such as user terminals in the cell can perform combined reception during the discovery period, and can also randomize collisions between cells. Both methods are effective from the viewpoint of coverage expansion, and can reduce the amount of information related to signaling related to initial resource allocation.

  FIG. 6 is a diagram illustrating an example of repeated transmission and hopping of type 2A / 2B discovery according to an embodiment of the present invention. In FIG. 6, each D2D resource group in the Tth and T + 1th discovery periods is divided, and a discovery signal (D2D signal) is hopped in each divided subresource group.

  In FIG. 6, r (T, k) is a discovery transmission resource used for the kth time in the T period, and f (r) is a transmission resource from r (T, k) to r (T, k + 1). G (r) represents a function for determining the transmission resource of r (T + 1, k) from r (T, k).

  In addition, in FIG. 6, the hopping pattern of f (r) or f (g (r)) is applied between these resources for f and fg attached to the arrows connecting the transmission resources of the D2D signal. Indicates. That is, in FIG. 6, as the hopping pattern, f (r) is applied within the discovery period, and f (g (r)) is applied between the discovery periods.

  Thus, the resource position to which the D2D signal is allocated is determined based on some hopping pattern in at least one sub-resource group. Here, hopping patterns used as f (r) and g (r) will be described with examples.

  As f (r), a hopping pattern common to all cells is preferable. According to this, when the D2D signal is repeatedly transmitted, it is easy to enable the combined reception by the user terminal of the adjacent cell. Further, as f (r), for example, a transmission subframe hopping pattern for reducing the influence of a non-receivable subframe due to a half duplex restriction that reception is not possible during transmission is preferable. Further, f (r) is preferably a frequency hopping pattern for reducing the influence of frequency selective fading.

  As g (r), a cell-specific hopping pattern is preferable. According to this, the collision between cells can be randomized. Here, g (r) may notify the hopping pattern for each cell by higher layer signaling (for example, including notification by SIB and RRC signaling). G (r) is a cell ID (also called a physical cell ID), a virtual cell ID (virtual cell ID), an ID of a D2D synchronization signal (D2DSS: D2D Synchronization Signal), and an SA ID (ID used in SA). An implicit determination may be made based on at least one of the following.

  By making g (r) common to the user terminals in the cell, the user terminals in the cell can also synthesize and receive discovery signals between discovery periods. Also, as g (r), a specific pattern may be used outside the cell coverage. The specific pattern may be a common pattern for several user terminals or may be a different pattern.

  Note that f (r) and g (r) may be divided into time and frequency hopping patterns and applied individually in a predetermined order. For example, f (r) may be a function that obtains the time position and frequency position of the transmission resource separately by a plurality of expressions, or may be a function that obtains simultaneously by one expression.

  The above-described f (r) and g (r) do not limit a specific hopping pattern, but are not limited to these. For example, a hopping rule (TF switching hopping rule) for switching the order of resource allocation in the time direction and the frequency direction may be applied to f (r), and a cyclic shift (time domain or frequency domain) (g (r)). Time or frequency domain cyclic shifting) may be applied.

  7 to 12 are diagrams showing examples of repetitive transmission and hopping of type 2A / 2B discovery according to an embodiment of the present invention, respectively, similarly to FIG. In each example, the applied hopping pattern is different. In the following, effects obtained in each configuration will be described in the case where f (r) is a hopping pattern common to all cells and g (r) is a hopping pattern common to user terminals in the cell.

  FIG. 7 shows an example in which the hopping patterns within and between the discovery periods are independent. In FIG. 7, as the hopping pattern, f (r) is applied within a period, and g (r) is applied between periods. In this case, the synthesis within the discovery cycle can be performed at all user terminals. On the other hand, combining between periods is effective for some user terminals, but it is possible to avoid resource collision between cells.

  FIG. 8 to FIG. 10 respectively show examples of cases in which the hopping patterns within the discovery period and between the periods are common. 8 to 10, f (r), g (r), and f (g (r)) are applied as hopping patterns, respectively. In the case of FIG. 8, there is a possibility that resource collision between cells may occur continuously, but it is possible to combine within the discovery period and between the periods. On the other hand, in the case of FIG. 9 and FIG. 10, combining within the discovery period and between the periods is effective for some user terminals, but it is possible to avoid inter-cell resource collision.

  FIG. 11 shows an example when the application order of the function of the hopping pattern during the discovery period is reversed in FIG. In FIG. 11, f (r) is applied within a period and g (f (r)) is applied between periods as a hopping pattern. In this case, the synthesis within the discovery cycle can be performed at all user terminals. On the other hand, combining between periods is effective for some user terminals, but it is possible to avoid resource collision between cells.

  FIG. 12 shows an example when the hopping patterns within and between the discovery periods in FIG. 7 are exchanged. In FIG. 12, g (r) is applied within a period and f (r) is applied between periods as a hopping pattern. In this case, composition within the discovery period is effective for some user terminals. As a result, synthesis between cycles is effective for some user terminals, but inter-cell resource collision can be avoided.

  In addition, the application method of a hopping pattern is not restricted to this, You may change suitably or may use it in combination. For example, as a hopping pattern, f (r) may be applied within a certain period, and f (g (r)) may be applied within a different period.

(Type 1 discovery resource decision)
In the resource determination for type 1 discovery, the transmission pattern within one discovery period is determined by any one of the methods described above for type 2A / 2B discovery or a combination thereof. Thereby, the user terminal on the receiving side can perform combined reception of the discovery signal. However, the discovery signal transmission resource in the first sub-resource group within a predetermined discovery cycle is selected from the type 1 resource group by the user terminal.

  FIG. 13 is a diagram illustrating an example of repeated transmission and hopping of type 1 discovery according to an embodiment of the present invention. In FIG. 13, f (r) is applied as a hopping pattern within the discovery period. In addition, the application method of a hopping pattern is not restricted to this, You may change suitably or may be used in combination as mentioned above by the type 2A / 2B discovery.

(SA resource determination in D2D communication)
In SA resource determination in D2D communication, a transmission pattern in one SA resource pool is determined by any one or a combination of the methods described above for type 2A / 2B discovery. Thereby, the user terminal on the receiving side can perform the composite reception of SA. However, the SA transmission resource in the first sub-resource group in the predetermined SA resource pool uses (E) the D2D resource notified from the network by PDCCH (in the case of mode 1 communication), or the SA resource pool by the user terminal (In the case of mode 2 communication).

  FIG. 14 is a diagram illustrating an example of SA repeated transmission and hopping in D2D communication according to an embodiment of the present invention. In FIG. 14, f (r) is applied within the SA resource pool as a hopping pattern. In addition, the application method of a hopping pattern is not restricted to this, You may change suitably or may be used in combination as mentioned above by the type 2A / 2B discovery.

  Further, when scheduling a plurality of SAs with one grant, resource determination by hopping may be performed between different SAs (between resource pools and transport blocks) as in the hopping pattern between discovery periods.

  FIG. 15 is a diagram illustrating an example of SA repeated transmission and hopping in D2D communication according to an embodiment of the present invention. In FIG. 15, f (r) is applied within the SA resource pool and f (g (r)) is applied between the SA resource pools as the hopping pattern. In addition, the application method of a hopping pattern is not restricted to this, You may change suitably or may be used in combination as mentioned above by the type 2A / 2B discovery.

(D2D data resource determination in D2D communication)
In the D2D data resource determination in the D2D communication, the transmission pattern in the D2D data resource pool is determined by any one of the methods described above in the type 2A / 2B discovery or a combination thereof. Thereby, the user terminal on the receiving side can perform composite reception of D2D data. However, the transmission resource of D2D data in the first sub-resource group in the predetermined D2D data resource pool is determined by the corresponding SA.

  FIG. 16 is a diagram illustrating an example of repeated transmission and hopping of D2D data in D2D communication according to an embodiment of the present invention. In FIG. 16, f (r) is applied in the resource pool for D2D data as a hopping pattern. In addition, the application method of a hopping pattern is not restricted to this, You may change suitably or may be used in combination as mentioned above by the type 2A / 2B discovery.

  As described above, in each embodiment, a hopping pattern can be shared between user terminals. By sharing the hopping pattern used for D2D discovery, the reception operation between type 1 / 2A / 2B discovery can be made common, and the amount of signaling for receiving each signal can be reduced. Further, by sharing the hopping pattern used for D2D communication, the reception operation between the mode 1/2 communication can be made common, and the signaling amount for receiving each signal can be reduced.

  For example, when a D2D signal from a user terminal using a common hopping pattern is received in any subframe group, the subsequent D2D signal is transmitted based on the resource position of the received signal and the hopping pattern. The resource location can be obtained and combined reception can be performed without additional signaling.

  In addition, even when transmission resource pools of different types of discovery are overlapped, the hopping pattern can be made common within the discovery period, so that the operation of the receiver is not complicated and the implementation cost of the user terminal is reduced. Can do.

  In addition, by using a hopping pattern that is common between cells and a hopping pattern that is different between cells at appropriate periods, combined reception of D2D signals from other cells, and randomization of D2D transmission resource collisions between cells, Can be realized.

  In the above example, only the D2D resource group that determines the transmission resource according to one type / mode is shown, but the present invention is not limited to this. For example, D2D signal allocation resources may be determined according to different types in a plurality of D2D resource groups. Specifically, D2D signal allocation resources may be determined according to type 1 discovery in a certain D2D resource group and type 2B discovery in a different resource group.

  Further, the user terminal may receive information regarding the type / mode switching, and may appropriately switch the type / mode used for resource determination according to the information. Even when the types are switched, for example, when a common hopping pattern is used for different types, combined reception is possible without additional signaling regarding the hopping pattern.

(Configuration of wireless communication system)
Hereinafter, the configuration of a wireless communication system according to an embodiment of the present invention will be described. In this wireless communication system, the D2D resource determination method according to each of the above embodiments is applied.

  FIG. 17 is a schematic configuration diagram illustrating an example of a wireless communication system according to an embodiment of the present invention. As shown in FIG. 17, the radio communication system 1 includes a plurality of radio base stations 10 and a plurality of user terminals that are in a cell formed by each radio base station 10 and configured to be communicable with each radio base station 10. 20. Each of the radio base stations 10 is connected to the higher station apparatus 30 and connected to the core network 40 via the higher station apparatus 30.

  The radio base station 10 is a radio base station having a predetermined coverage. The radio base station 10 may be a macro base station having a relatively wide coverage or a small base station having a local coverage.

  Note that the macro base station may be called an eNB (eNodeB), an aggregation node, a transmission point, or the like. The small base station may be called a micro base station, a pico base station, a femto base station, a HeNB (Home eNodeB), an RRH (Remote Radio Head), a transmission point, or the like.

  In the cell formed by each radio base station 10, the same frequency band may be used or different frequency bands may be used. The radio base stations 10 may be connected to each other via an interface between base stations (for example, an optical fiber or an X2 interface).

  The user terminal 20 is a terminal that supports various communication schemes such as LTE, LTE-A, and FRA, and may include not only a mobile communication terminal but also a fixed communication terminal. The user terminal 20 can communicate with other user terminals 20 via the radio base station 10. Further, the user terminal 20 can communicate with other user terminals 20 by D2D without going through the radio base station 10.

  The upper station apparatus 30 includes, for example, an access gateway apparatus, a radio network controller (RNC), a mobility management entity (MME), and the like, but is not limited thereto.

  In the radio communication system 1, OFDMA (Orthogonal Frequency Division Multiple Access) is applied to the downlink and SC-FDMA (Single Carrier Frequency Division Multiple Access) is applied to the uplink as the radio access scheme. The uplink and downlink radio access methods are not limited to these combinations.

  In the wireless communication system 1, a downlink shared channel (PDSCH) broadcast channel (PBCH) shared by each user terminal 20 and a downlink L1 / L2 control channel are used as downlink channels. It is done. User data, higher layer control information, and predetermined SIB (System Information Block) are transmitted by the PDSCH. A synchronization signal, MIB (Master Information Block), and the like are transmitted by the PBCH.

  Downlink L1 / L2 control channels include PDCCH (Physical Downlink Control Channel), EPDCCH (Enhanced Physical Downlink Control Channel), PCFICH (Physical Control Format Indicator Channel), PHICH (Physical Hybrid-ARQ Indicator Channel), and the like. Downlink control information (DCI) including scheduling information of PDSCH and PUSCH is transmitted by PDCCH. The number of OFDM symbols used for PDCCH is transmitted by PCFICH. The HAICH transmission confirmation signal (ACK / NACK) for PUSCH is transmitted by PHICH. The EPDCCH is frequency division multiplexed with a PDSCH (downlink shared data channel) and may be used to transmit DCI or the like in the same manner as the PDCCH.

  In the wireless communication system 1, as an uplink channel, an uplink shared channel (PUSCH) shared by each user terminal 20, an uplink control channel (PUCCH), a random access channel (PRACH: PRACH). Physical Random Access Channel) is used. User data and higher layer control information are transmitted by PUSCH. Also, downlink radio quality information (CQI: Channel Quality Indicator), a delivery confirmation signal, and the like are transmitted by PUCCH. A random access preamble (RA preamble) for establishing a connection with the cell is transmitted by the PRACH.

  Moreover, in the radio | wireless communications system 1, the user terminal 20 transmits D2D signal using an uplink. However, the present invention is not limited to this, and the D2D signal may be transmitted using a radio access scheme different from the uplink and / or a different radio resource.

  FIG. 18 is an overall configuration diagram of the radio base station 10 according to an embodiment of the present invention. The radio base station 10 includes a plurality of transmission / reception antennas 101 for MIMO transmission, an amplifier unit 102, a transmission / reception unit 103, a baseband signal processing unit 104, a call processing unit 105, and a transmission path interface 106. Yes. The transmission / reception unit 103 includes a transmission unit and a reception unit.

  User data transmitted from the radio base station 10 to the user terminal 20 via the downlink is input from the higher station apparatus 30 to the baseband signal processing unit 104 via the transmission path interface 106.

  The baseband signal processing unit 104 processes PDCP (Packet Data Convergence Protocol) layer processing, user data division / combination, RLC (Radio Link Control) retransmission control and other RLC layer transmission processing, MAC (Medium Access) for user data. Control) Retransmission control (for example, transmission processing of HARQ (Hybrid Automatic Repeat reQuest)), scheduling, transmission format selection, channel coding, inverse fast Fourier transform (IFFT) processing, precoding processing, etc. Is transferred to each transceiver 103. The downlink control signal is also subjected to transmission processing such as channel coding and inverse fast Fourier transform, and transferred to each transmitting / receiving unit 103.

  Each transmitting / receiving unit 103 converts the downlink signal output by precoding from the baseband signal processing unit 104 for each antenna into a radio frequency band and transmits the converted signal. The radio frequency signal frequency-converted by the transmission / reception unit 103 is amplified by the amplifier unit 102 and transmitted from the transmission / reception antenna 101. Further, the transmission / reception unit 103 transmits information regarding the D2D resource group, information regarding the initial allocation position of the D2D resource, and the like to each user terminal 20. The transmission / reception unit 103 can be a transmitter / receiver, a transmission / reception circuit, or a transmission / reception device described based on common recognition in the technical field according to the present invention.

  On the other hand, for the uplink signal, the radio frequency signal received by each transmission / reception antenna 101 is amplified by the amplifier unit 102. Each transmitting / receiving unit 103 receives the upstream signal amplified by the amplifier unit 102. The transmission / reception unit 103 converts the frequency of the received signal into a baseband signal and outputs it to the baseband signal processing unit 104.

  The baseband signal processing unit 104 performs Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing, and error correction on user data included in the input upstream signal. Decoding, MAC retransmission control reception processing, RLC layer, and PDCP layer reception processing are performed and transferred to the upper station apparatus 30 via the transmission path interface 106. The call processing unit 105 performs call processing such as communication channel setting and release, state management of the radio base station 10, and radio resource management.

  The transmission path interface 106 transmits and receives signals to and from the higher station apparatus 30 via a predetermined interface. Further, the transmission path interface 106 may transmit / receive a signal (backhaul signaling) to / from an adjacent radio base station via an interface between base stations (for example, an optical fiber or an X2 interface). For example, the transmission path interface 106 may transmit / receive information regarding the D2D resource group for each user terminal 20, information regarding the initial allocation position of the D2D resource, and the like to / from adjacent radio base stations.

  FIG. 19 is a main functional configuration diagram of the baseband signal processing unit 104 included in the radio base station 10 according to the embodiment of the present invention. Note that FIG. 19 mainly shows functional blocks of characteristic portions in the present embodiment, and the wireless base station 11 also has other functional blocks necessary for wireless communication.

  As illustrated in FIG. 19, the baseband signal processing unit 104 included in the radio base station 10 includes at least a control unit (scheduler) 301, a transmission signal generation unit 302, a mapping unit 303, and a reception signal processing unit 304. It is configured to include.

  The control unit 301 performs radio resource scheduling control (allocation control) for downlink signals and uplink signals based on instruction information from the higher station apparatus 30 and feedback information from each user terminal 20. That is, the control unit 301 has a function as a scheduler. In addition, when the other radio base station 10 and the higher station apparatus 30 function as a scheduler of the radio base station 10, the control unit 301 does not need to function as a scheduler. The control unit 301 may be a controller, a control circuit, or a control device described based on common recognition in the technical field according to the present invention.

  The control unit 301 controls the transmission signal generation unit 302 and the mapping unit 303. Specifically, the control unit 301 controls scheduling of a downlink reference signal, a downlink data signal transmitted by PDSCH, a downlink control signal transmitted by PDCCH and / or EPDCCH, and the like. In addition, the control unit 301 controls scheduling such as an uplink reference signal, an uplink data signal transmitted by PUSCH, an uplink control signal transmitted by PUCCH and / or PUSCH, and an RA preamble transmitted by PRACH.

  For example, the control unit 301 can control radio resource allocation based on instruction information from the higher station apparatus 30 and feedback information (for example, channel state information (CSI)) reported from the user terminal 20. Information on allocation control is notified to the user terminal 20 using downlink control information (DCI).

  Moreover, the control part 301 sets the time / frequency resource group (D2D resource group) which can allocate D2D signal with respect to the user terminal 20 which can transmit / receive D2D signal. For example, the D2D resource group may be set at a predetermined cycle. Then, the transmission signal generation unit 302 and the mapping unit 303 are controlled so as to generate and transmit information regarding the D2D resource group, information regarding the initial allocation position of the D2D resource, and the like to each user terminal 20.

  The transmission signal generation unit 302 generates a downlink control signal, a downlink data signal, a downlink reference signal, and the like whose assignment is determined by the control unit 301, and outputs the generated signal to the mapping unit 303. Specifically, based on an instruction from the control unit 301, the transmission signal generation unit 302 generates a DL assignment for notifying downlink signal allocation information and a UL grant for notifying uplink signal allocation information. Also, the downlink data signal is subjected to encoding processing and modulation processing according to the coding rate and modulation scheme determined based on CSI from each user terminal 20 and the like. The transmission signal generation unit 302 may be a signal generator or a signal generation circuit described based on common recognition in the technical field according to the present invention.

  Further, based on an instruction from the control unit 301, the transmission signal generation unit 302 may generate higher layer signaling (including SIB and RRC) including PDB information, PD2DSCH, and the like as downlink signals. In addition, the transmission signal generation unit 302 may generate information related to a hopping pattern common to cells and / or a cell-specific hopping pattern based on an instruction from the control unit 301.

  Based on an instruction from the control unit 301, the mapping unit 303 maps the downlink signal generated by the transmission signal generation unit 302 to a radio resource and outputs it to the transmission / reception unit 103. The mapping unit 303 can be a mapping circuit or a mapper described based on common recognition in the technical field according to the present invention.

  The reception signal processing unit 304 performs reception processing (for example, demapping and demodulation) on an uplink signal (for example, a delivery confirmation signal (HARQ-ACK), a data signal transmitted by PUSCH, and the like) transmitted from the user terminal. , Decryption, etc.). The reception signal processing unit 304 can be a signal processor or a signal processing circuit described based on common recognition in the technical field according to the present invention.

  The received signal processing unit 304 may measure the received power (RSRP) and the channel state using the received signal. Reception signal processing section 304 may determine whether or not retransmission control is required for each subframe based on the decoding result of the received signal. Information extracted from the received signal by the received signal processing unit 304 and information acquired by measurement are output to the control unit 301.

  FIG. 20 is an overall configuration diagram of the user terminal 20 according to an embodiment of the present invention. Note that FIG. 20 mainly shows functional blocks of characteristic portions in the present embodiment, and the user terminal 20 also has other functional blocks necessary for wireless communication.

  As shown in FIG. 20, the user terminal 20 includes a plurality of transmission / reception antennas 201 for MIMO transmission, an amplifier unit 202, a transmission / reception unit 203, a baseband signal processing unit 204, and an application unit 205. Yes. Note that the transmission / reception unit 203 may include a transmission unit and a reception unit.

  Radio frequency signals received by the plurality of transmission / reception antennas 201 are each amplified by the amplifier unit 202. Each transmitting / receiving unit 203 receives the downlink signal amplified by the amplifier unit 202. The transmission / reception unit 203 converts the frequency of the received signal into a baseband signal and outputs it to the baseband signal processing unit 204. The transmission / reception unit 203 can be a transmitter / receiver, a transmission / reception circuit, or a transmission / reception device described based on common recognition in the technical field according to the present invention.

  The baseband signal processing unit 204 performs FFT processing, error correction decoding, retransmission control reception processing, and the like on the input baseband signal. The downlink user data is transferred to the application unit 205. The application unit 205 performs processing related to layers higher than the physical layer and the MAC layer. In addition, broadcast information in the downlink data is also transferred to the application unit 205.

  On the other hand, uplink user data is input from the application unit 205 to the baseband signal processing unit 204. The baseband signal processing unit 204 performs retransmission control transmission processing (for example, HARQ transmission processing), channel coding, precoding, discrete Fourier transform (DFT) processing, IFFT processing, and the like. The data is transferred to the transmission / reception unit 203. The transmission / reception unit 203 converts the baseband signal output from the baseband signal processing unit 204 into a radio frequency band and transmits it. The radio frequency signal frequency-converted by the transmission / reception unit 203 is amplified by the amplifier unit 202 and transmitted from the transmission / reception antenna 201.

  FIG. 21 is a main functional configuration diagram of the baseband signal processing unit 204 included in the user terminal 20. As illustrated in FIG. 21, the baseband signal processing unit 204 included in the user terminal 20 includes at least a control unit 401, a transmission signal generation unit 402, a mapping unit 403, and a reception signal processing unit 404. ing.

  The control unit 401 obtains, from the reception signal processing unit 404, a downlink control signal (signal transmitted by PDCCH / EPDCCH) and a downlink data signal (signal transmitted by PDSCH) transmitted from the radio base station 10. The control unit 401 generates an uplink control signal (for example, an acknowledgment signal (HARQ-ACK)) or an uplink data signal based on a downlink control signal, a result of determining whether retransmission control is necessary for the downlink data signal, or the like. To control. Specifically, the control unit 401 controls the transmission signal generation unit 402 and the mapping unit 403. The control unit 401 may be a controller, a control circuit, or a control device described based on common recognition in the technical field according to the present invention.

  The control unit 401 determines the D2D resource based on information on the D2D resource group (for example, information on the size of the resource block) included in the received signal transmitted from the radio base station 10, information on initial resource allocation of the D2D signal, and the like. Set.

  In addition, the control unit 401 includes a dividing unit 411 and a resource position determining unit 412. The dividing unit 411 divides the set D2D resource group into a plurality of sub resource groups. The said division | segmentation is implemented using the information (for example, subresource group information) for dividing | segmenting a D2D resource group into several subresource groups notified by higher layer signaling (including SIB, RRC), PD2DSCH, etc. May be. The dividing unit 411 and the resource position determining unit 412 may be configured by a controller, a control circuit, or a control device described based on common recognition in the technical field according to the present invention, or may be a resource manager, a resource management circuit, or a resource You may comprise from a management apparatus.

  The resource position determination unit 412 determines a resource position to which the same D2D signal is allocated in each sub resource group divided by the division unit 411. The resource location can be determined using a hopping pattern as shown in FIGS. The hopping pattern is preferably shared by D2D discovery signals between different types. The hopping pattern is preferably shared by D2D communication signals (SA and / or D2D data) between different modes. The hopping pattern may be common to a plurality of D2D signals. For example, the same hopping pattern may be used for all D2D signals. Further, the hopping pattern may be common between cells or may be cell specific.

  Further, the resource position determination unit 412 determines a resource position in a subframe group belonging to a predetermined D2D resource group, a resource position in a subframe group belonging to a D2D resource group different from the D2D resource group, a predetermined hopping pattern, , May be determined based on. For example, the resource position in the first sub-resource group belonging to a predetermined D2D resource group is determined based on the resource position and the hopping pattern in the last sub-resource group belonging to the D2D resource group in the previous period of the D2D resource group May be. In addition, the hopping pattern applied between such different D2D resource groups may be different from the hopping pattern applied within the D2D resource group, or may be a cell-specific hopping pattern.

  The control unit 401 uses the resource position determined by the resource position determination unit 412 to cause the transmission signal generation unit 402 to generate a predetermined D2D signal and repeatedly transmits the D2D signal using a plurality of D2D resources. Control to map to.

  Based on an instruction from the control unit 401, the transmission signal generation unit 402 generates an uplink control signal such as a delivery confirmation signal (HARQ-ACK) and channel state information (CSI). In addition, the transmission signal generation unit 402 generates an uplink data signal based on an instruction from the control unit 401. The transmission signal generation unit 402 can be a signal generator or a signal generation circuit described based on common recognition in the technical field according to the present invention.

  Note that the control unit 401 instructs the transmission signal generation unit 402 to generate an uplink data signal when the UL grant is included in the downlink control signal notified from the radio base station. In addition, when the control signal notified from the radio base station includes a D2D data grant, the control unit 401 instructs the transmission signal generation unit 402 to generate D2D data.

  The mapping unit 403 maps the uplink signal generated by the transmission signal generation unit 402 to a radio resource based on an instruction from the control unit 401, and outputs the radio signal to the transmission / reception unit 203. For example, the mapping unit 403 allocates the D2D signal to the D2D resource group based on an instruction from the control unit 401. The transmission unit in the present embodiment may be configured by the mapping unit 403 and the transmission / reception unit 203, and can repeatedly transmit the D2D signal by mapping the D2D signal to the resource position determined by the resource position determination unit 412. The mapping unit 403 can be a mapping circuit or a mapper described based on common recognition in the technical field according to the present invention.

  The reception signal processing unit 404 performs reception processing on received signals (for example, downlink control signals transmitted from radio base stations, downlink data signals transmitted on PDSCH, D2D signals transmitted from other user terminals, etc.). (For example, demapping, demodulation, decoding, etc.) are performed. The reception signal processing unit 404 can be a signal processor or a signal processing circuit described based on common recognition in the technical field according to the present invention.

  In this embodiment, since the D2D signal from the other user terminal 20 is transmitted in a plurality of subframe groups, the reception signal processing unit 404 synthesizes and receives the same plurality of received D2D signals. For combining reception, diversity combining can be used, for example. Further, the received signal processing unit 404 may measure the received power (RSRP) and the channel state using the received signal. Reception signal processing section 404 may determine whether or not retransmission control is required for each subframe based on the decoding result of the received signal.

  Information extracted from the received signal by the received signal processing unit 404 and information acquired by measurement are output to the control unit 401. For example, the received signal processing section 404 displays scheduling information (such as allocation information to uplink resources) included in the downlink control signal, information on a cell that feeds back an acknowledgment signal to the downlink control signal, a channel state, and the like. Output to. Also, the received signal processing unit 404 outputs information related to the D2D resource group included in the received signal, information related to initial resource allocation of the D2D signal, and the like to the control unit 401.

  In addition, the block diagram used for description of the said embodiment has shown the block of the functional unit. These functional blocks (components) are realized by any combination of hardware and software. Further, the means for realizing each functional block is not particularly limited. That is, each functional block may be realized by one physically coupled device, or may be realized by two or more physically separated devices connected by wire or wirelessly and by a plurality of these devices. Good.

  For example, some or all of the functions of the radio base station 10 and the user terminal 20 are realized using hardware such as an application specific integrated circuit (ASIC), a programmable logic device (PLD), and a field programmable gate array (FPGA). May be. Further, the radio base station 10 and the user terminal 20 may be realized by a computer apparatus including a processor (CPU), a communication interface for network connection, a memory, and a computer-readable storage medium holding a program. Good.

  Here, the processor, the memory, and the like are connected by a bus for communicating information. The computer-readable recording medium is a storage medium such as a flexible disk, a magneto-optical disk, a ROM, an EPROM, a CD-ROM, a RAM, and a hard disk. In addition, the program may be transmitted from a network via a telecommunication line. The radio base station 10 and the user terminal 20 may include an input device such as an input key and an output device such as a display.

  The functional configurations of the radio base station 10 and the user terminal 20 may be realized by the hardware described above, may be realized by a software module executed by a processor, or may be realized by a combination of both. The processor controls the entire user terminal by operating an operating system. Further, the processor reads programs, software modules and data from the storage medium into the memory, and executes various processes according to these. Here, the program may be a program that causes a computer to execute the operations described in the above embodiments. For example, the control unit 401 of the user terminal 20 may be realized by a control program stored in a memory and operated by a processor, and may be realized similarly for other functional blocks.

  Although the present invention has been described in detail above, it will be apparent to those skilled in the art that the present invention is not limited to the embodiments described herein. For example, the above-described embodiments may be used alone or in combination. The present invention can be implemented as modified and changed modes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention.

DESCRIPTION OF SYMBOLS 1 ... Wireless communication system 10 ... Wireless base station 20 ... User terminal 30 ... Host station apparatus 40 ... Core network 101 ... Transmission / reception antenna 102 ... Amplifier part 103 ... Transmission / reception part (transmission part)
104 ... baseband signal processing unit 105 ... call processing unit 106 ... transmission path interface 201 ... transmission / reception antenna 202 ... amplifier unit 203 ... transmission / reception unit (transmission unit / reception unit)
204 ... Baseband signal processing unit 205 ... Application unit 301 ... Control unit (scheduler)
302 ... Transmission signal generation unit 303 ... Mapping unit 304 ... Reception signal processing unit 401 ... Control unit 402 ... Transmission signal generation unit 403 ... Mapping unit 404 ... Reception signal processing unit 411 ... Division unit 412 ... Resource position determination unit

Claims (10)

A division unit that divides a D2D resource group capable of assigning a D2D signal into a plurality of sub-resource groups;
A resource position determination unit that determines a resource position to which a D2D signal is allocated within at least one sub-resource group based on a first hopping pattern;
A user terminal comprising: a transmission unit configured to map a D2D signal and repeatedly perform transmission at the resource position.   The user terminal according to claim 1, wherein the resource location determination unit uses a common hopping pattern as the first hopping pattern for D2D discovery signals between different types.   The user terminal according to claim 1 or 2, wherein the resource position determination unit uses a common hopping pattern as the first hopping pattern for D2D communication signals between different modes.   The resource position determination unit includes a resource position in a subframe group belonging to a predetermined D2D resource group, a resource position in a subframe group belonging to a D2D resource group different from the D2D resource group, a second hopping pattern, The user terminal according to claim 1, wherein the determination is made based on:   The user terminal according to claim 4, wherein the resource location determination unit uses a cell-specific hopping pattern as the second hopping pattern.   The user terminal according to claim 1, further comprising: a receiving unit that receives information for dividing the D2D resource group into a plurality of sub-resource groups. The receiving unit receives the number of repeated transmissions as the information,
The user terminal according to claim 6, wherein the dividing unit divides the D2D resource group based on the number of times of repeated transmission. A division unit that divides a D2D resource group capable of assigning a D2D signal into a plurality of sub-resource groups;
A resource position determination unit that determines a resource position to which a D2D signal is allocated in at least one of the sub-resource groups based on a first hopping pattern;
And a receiving unit that synthesizes and receives a D2D signal transmitted from another user terminal at the resource position. A radio base station that communicates with a user terminal capable of transmitting and receiving D2D signals,
A control unit configured to set a D2D resource group capable of assigning a D2D signal to the user terminal;
And a transmitter that transmits information for dividing the D2D resource group into a plurality of sub-resource groups. The user terminal divides a D2D resource group that can be assigned a D2D signal into a plurality of sub-resource groups;
Determining a resource location to allocate a D2D signal within the at least one sub-resource group based on a first hopping pattern;
Mapping the D2D signal to the resource position and repeatedly performing transmission.

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