Patent Description:
Techniques for assigning resources in device to device (D2D) communication between terminal devices have been disclosed (for example, Patent Literature <NUM>).

On the other hand, in recent years, anticipation of in-vehicle communication (V2X communication) to implement future automatic driving has been increasing. "V2X communication" is an abbreviation of "vehicle to X communication" and refers to a system in which a "vehicle" communicates with an "object. " Here, examples of the "object" include a vehicle, a facility (infrastructure/network), and a pedestrian (V2V, V2I/N, and V2P). As wireless communication for vehicles, development of <NUM> p-based dedicated short range communication (DSRC) has mainly advanced so far, but in recent years, discussions on standardization of "LTE-based V2X" which is LTE-based in-vehicle communication have started. Non patent literature <NUM> discloses "Distributed Resource Allocation for V2X over PCS". Non-patent literature <NUM> discloses "V2V System Level Performance". Non-patent literature <NUM> discloses scan-based collision avoidance in V2V communication. Patent Literature <NUM> discloses a monitoring system and monitoring method.

The present disclosure proposes a device and a method which are novel and improved and capable of performing efficient resource sensing in V2X communication.

As described above, according to the present disclosure, it is possible to provide a device and a method which are novel and improved and capable of performing efficient resource sensing in V2X communication.

Further, the description will proceed in the following order.

First, an overview of an embodiment of the present disclosure will be described.

As described above, in recent years, anticipation of in-vehicle communication (V2X communication) to implement future automatic driving has been increasing. "V2X communication" is an abbreviation of "vehicle to X communication" and refers to a system in which a "vehicle" communicates with an "object. " Here, examples of the "object" include a vehicle, a facility (infrastructure/network), and a pedestrian (V2V, V2I/N, and V2P). As wireless communication for vehicles, development of <NUM>. 11p-based DSRC has mainly advanced so far, but in recent years, discussions on standardization of "LTE-based V2X" which is LTE-based in-vehicle communication have started.

Examples of cases in which V2X communication is used are listed below. There have been demands for communication such as periodic message transmission in which a message is periodically transmitted to a vehicle for the purpose of safety or an event trigger message providing necessary information in accordance with an event (3GPP TR <NUM>).

Examples of requirements based on these use cases are shown below.

To achieve the above requirements, standardization of a physical layer of V2X communication has already started in 3GPP. V2I/N and V2P have been standardized while focus has been performed focusing on standardization of the V2V communication which is inter-vehicle communication.

A base technology of V2X communication is D2D communication which was standardized in 3GPP in the past. Since D2D communication is inter-terminal communication that does not go through a base station, enhancing it by applying it to V2V communication and V2P communication (it can also be applied to some V2I communication) can be considered. Such an interface between terminals is referred to as a PC5 interface.

Further, enhancing V2I communication and V2N communication by applying them to existing communication between a base station and a terminal can be considered. Such an interface between a base station and a terminal is referred to as a Uu interface.

As described above, in order to implement V2X communication, it is necessary to enhance the PC5 interface and the Uu interface to meet the requirements.

The main enhancement points include, for example, improvement of resource allocation, countermeasures against a Doppler frequency, establishment of a synchronization technique, implementation of low power consumption communication, implementation of low delay communication, and so on.

A V2X operation scenario will be described. It is based on the V2V communication. Further, in the following description, if one automobile is replaced with a pedestrian, it becomes V2P communication, and in a case in which it terminates at a facility or a network, it becomes V2I/N communication.

<FIG> are explanatory diagrams for describing the V2X operation scenario. <FIG> illustrates a scenario in which vehicles communicate directly with each other without a base station (E-UTRAN). <FIG> illustrates a scenario in which vehicles communicate via a base station. <FIG> and <FIG> illustrate a scenario in which vehicles communicate via a terminal (a UE, here, a roadside wireless device (RSU)) and a base station. <FIG> illustrates a scenario in which vehicles communicate via a terminal (a UE, here, a roadside wireless device (RSU)).

Since V2X communication is different from D2D in communication requirements, communication environment, or the like, the existing D2D communication is unable to be used without change. Therefore, it is necessary to enhance it to a form of adapting to V2X communication. Feature differences between D2D communication and V2X communication are illustrated below.

First, (<NUM>) is obvious from the use cases of V2X communication. V2X communication has many safety purposes, and the reliability is a very important index. Further, since a moving speed of a vehicle is faster than that in a walking use case of D2D, implementation of low delay communication is necessary.

For the traffic specific to V2X of (<NUM>), mainly two types of traffic, that is, periodic traffic and event trigger traffic, are assumed in V2X communication. The periodic traffic is communication of periodically notifying peripheral vehicles of data, and it is also a feature of V2X.

For the various links of (<NUM>), V (vehicle)/I (infrastructure)/N (network)/P (pedestrian) are assumed as communication targets (X) of the vehicle in V2X communication. A point having such various links is also unique to V2X communication.

The IBE problem of (<NUM>) and the HD problem of (<NUM>) are related to topology and RF performance of a terminal. First, the IBE will be described with reference to <FIG>. Unlike the communication between the base station and the terminal, in the V2V communication, a position relation between a transmission terminal and a reception terminal consistently changes. In a case in which there is a reception terminal near the transmission terminal, emission from a transmission side may affect a nearby reception terminal. The orthogonality is maintained on a frequency axis, but influence of the IBE becomes remarkable from the proximity of the distance between the transmission terminal and the reception terminal. In <FIG>, a transmission terminal A gives the IBE to a reception terminal D. As described above, in a case in which the distance between the transmission terminal and the reception terminal is short, there is a possibility of interference occurring in adjacent resources on the frequency. This problem can happen even in D2D. However, in V2X communication in which more terminals communicate than that in D2D, the IBE problem becomes more noticeable.

The HD problem of (<NUM>) refers to a problem in that the terminal is unable to perform reception while performing transmission. For this reason, it is necessary to cope with it, for example, it is necessary to prepare two or more opportunities for receiving, and it is necessary to prevent transmission of other users from being assigned in a frame for transmitting data. The HD problem is not a problem specific to V2X, but it is a big restriction in V2X communication in which it is necessary to perform much transmission and reception.

Next, the capacity of (<NUM>) will be described. As described above, in V2X communication, the number of accommodated terminals is larger than that in D2D communication. Further, as an automobile travels on the road, a terminal density inevitably increases locally. For this reason, the improvement in the capacity is indispensable in V2X communication. It is necessary to eliminate as much unnecessary overhead and the like as possible and implement efficient communication.

The reason why the position information of the last (<NUM>) can consistently be obtained is because an automobile consistently knows its position information as can be seen from a navigation system installation of an automobile in recent years. Such position information becomes a very important feature in enhancing V2X communication.

In order to solve these problems, a resource allocation method using frequency division multiplexing (FDM) is currently under review in 3GPP. Time division multiplexing (TDM) assignment and FDM assignment will be described with reference to <FIG>. The PC5 interface in which D2D communication and V2X communication are performed is mainly configured with a control channel unit (physical sidelink control channel (PSCCH)) and a data channel unit (physical sidelink shared channel (PSSCH)).

Since a notification of a PSSCH resource indication or the like is performed in the PSCCH, there is a problem that a delay from generation to transmission of a packet becomes large in the TDM scheme. On the other hand, there is an advantage in that complexity of a terminal is excellent. Further, in D2D, the TDM assignment scheme is adopted. On the other hand, in the FDM scheme, since the PSCCH is mapped in the frequency direction, the delay is improved. Further, the problems of the IBE and the HD can be expected to be improved by transmitting scheduling assignment (SA) and data in the same SF (subframe). Therefore, in V2X communication, establishment of a communication method using the FDM scheme is necessary.

In addition to the FDM scheme, addition of further enhancement is under review as well. Introduction of semi-persistent scheduling (SPS) is also under review to solve the problem of the capacity of (<NUM>) described above. This makes good use of a characteristic of a traffic type having a feature in V2X communication. An overview of SPS is illustrated in <FIG>. In SPS, a plurality of pieces of data are scheduled with one SA. Therefore, it is unnecessary to transmit the SA each time data is transmitted, and the overhead can be reduced. Particularly, in the periodic communication such as the periodical traffic of V2X, it is confirmed that such scheduling produces a large effect. Therefore, introduction of SPS is also necessary in V2X communication.

Next, enhancement using the position information will be described with reference to <FIG> and <FIG>. As described in (<NUM>), the capacity is a big problem in V2X. Therefore, space reuse of frequency resources is under review. The position information of an automobile described in (<NUM>) is used in performing spatial reuse. Enhancement using the position information is also currently being discussed in 3GPP.

The overview of the enhancement of the PC5 interface has been described above. In V2X communication, there are two types of resource allocation, that is, centralized resource allocation of a mode <NUM> and autonomous resource selection of a mode <NUM>. In the case of the mode <NUM>, the base station performs all the resource allocation of the PC5 interface. The terminal side performs only transmission with the resources indicated to the base station. There is concern about the overhead between the base station and the terminal, but a communication characteristic is excellent because resources are assigned orthogonally. On the other hand, in the mode <NUM>, the terminal autonomously selects resources to be used for transmission from a resource pool notified of by the base station. There is no concern about overhead in the mode <NUM>, but since there is a possibility of selecting the same resources as other terminals, a collision problem arises. The mode <NUM> has an advantage in that it can operate not only in-coverage which is within a network of the base station but also out-of-coverage.

Several proposals are currently being presented on this collision problem in the mode <NUM>. The solutions can be roughly divided into two. One is energy sensing. Energy sensing is a method of sensing resources for a certain period of time and selecting communication resources from relatively unused resources on the basis of the sensing result. While it is simple, the accuracy is not that high since it is a power level. Here, it is possible to sense systems other than LTE. Another method is SA decoding. This is a method of decoding the SA (control information) transmitted by another user and recognizing a location of resources being used. The resources being used can be discovered with high accuracy, but there is a disadvantage in that sensing of SA resources is unable to be performed, and the resources being used are unable to be detected in a case in which the SA decoding fails.

Finally, a list describing enhancements performed so far is shown in Table <NUM>. These are only examples of representative enhancements, and various other methods are under review.

In a case in which there are one or more sensing modes, the UE does not know a sensing mode to be used in a given situation. Further, for the energy sensing, blind sensing is used for an SA pool and a data pool, but it is a sensing mode in which extreme levels of power are used by UEs carried by pedestrians.

Here, in an embodiment of the present disclosure, the UE is caused to set the sensing mode by two methods.

The first method is a method in which an eNB decides a sensing mode to be used. <FIG> is a flowchart illustrating a mode of deciding the sensing mode by an eNB, a transmission side UE, and a reception side UE.

The eNB decides a sensing mode and a sensing parameter. Then, the eNB generates a mapping table in which relations of the sensing mode and the sensing parameter with a state are specified. Then, the eNB decides the sensing mode and the sensing parameter and gives a notification indicating the sensing mode and the sensing parameter to the transmission side UE.

The transmission side UE sets the sensing mode and the sensing parameter notified of by the eNB, performs sensing in accordance with the sensing mode and the sensing parameter, and transmits the packet. The reception side UE receives the packet transmitted from the transmission side UE.

The second method is a method in which the UE decides a sensing mode to be used. <FIG> is a flowchart illustrating a mode of deciding the sensing mode by the eNB, the transmission side UE, and the reception side UE.

The eNB decides the sensing mode and the sensing parameter. Then, the eNB generates a mapping table in which relations of the sensing mode and the sensing parameter with the state are specified. Then, the eNB gives a notification of the mapping table to the reception side UE. The mapping table may be preconfigured on the terminal in advance.

Upon receipt of the notification of the mapping table, the reception side UE decides the sensing mode and the sensing parameter, performs sensing in accordance with the sensing mode and the sensing parameter, and transmits the packet. The reception side UE receives the packet transmitted from the transmission side UE.

The mapping table is a table in which the sensing mode to be used and the sensing parameter to be used are specified depending on a situation. Table <NUM> shows an example of the mapping table.

The "sensing mode" is used for the energy sensing, the SA decoding, or a combination thereof. Further, the "sensing mode" may be combined with data decoding, assistant sensing from eNB, or the like. Further, the data decoding is a scheme that decodes data of other terminals and checks a use situation of resources, and the assistant sensing from the eNB is a scheme that receives information of wireless environment information from the eNB and performs sensing.

Examples of "condition" include having a low power requirement, having a security requirement, having a low latency requirement, transmitting a periodic message or an event trigger message, having a high or low priority, a category, a type of sensing channel such as a PSCCH or a PSSCH, a type of the presence of other radio access technologies (RATs), a congestion degree of data traffic, a resource usage rate, and a terminal position.

The "sensing parameter" may include parameters such as a sensing interval, a sensing start time, and weight information, information of a restricted sensing area for saving a battery, and the like. The information of the restricted sensing area may include information of a sensing time interval or a frequency band, for example, information such as a frequency area to be sensed such as a bandwidth, a resource pool, and a subcarrier. The information of the restricted sensing area may also include a definition of a sensing area, for example, information of a block ID. The block ID is an ID attached to each partitioned pool. Further, the information of the restricted sensing area may include information of a location in which sensing is performed. The terminal performs designated sensing at a designated position.

The mapping table can be updated. The sensing mode can be changed depending on a given situation, and the sensing parameter can be changed depending on a given situation. Further, the sensing parameter can be changed depending on a given sensing mode.

The eNB evaluates whether a current mapping is not the best choice. Further, the UE reports to the eNB when the current mapping is not the best choice. Accordingly, the mapping table can be updated.

The eNB gives a notification indicating the mapping table, the sensing mode, and the sensing parameter to the UE, but, for example, the SIB or the DCI can be used for the notification. For example, the eNB broadcasts such information. For example, in a scenario of a coexisting DSRC, the eNB requests all UEs to select the energy sensing. Further, for example, the eNB gives a notification of information to a group of UEs or some UEs in a multicast manner. Further, for example, the eNB gives a notification of information to a unique UE in a unicast manner.

The mapping table can be transmitted, for example, at a timing at which an RRC connection is set up or reestablished. Further, the mapping table can be transmitted, for example, at an initially set timing. Further, the mapping table may be transmitted, for example, at an updated timing. Further, the mapping table may be transmitted, for example, at a timing at which the UE transmits the request for the mapping table. Further, the mapping table may also be periodically transmitted, for example, with a period specified by the UE.

It is inefficient and unnecessary that all the UEs perform sensing. In particular, in a case in which the sensing results are almost the same, it is desirable that the sensing results be shared.

Here, in an embodiment of the present disclosure embodiment, centralized sensing are executed by two methods.

A first method is a method in which the eNB or the RSU decides one or more representatives performing sensing. <FIG> is a flowchart illustrating an operation example of an eNB or an RSU, a node performing sensing as a representative, and other UEs when centralization of sensing is performed.

The eNB or the RSU specifies a condition for representing sensing, decides a node to be sensed as a representative, and transmits a message indicating that it is assigned as a representative to the decided node. The representative transmits ACK or NACK to the message indicating that it is assigned as a representative to the eNB or the RSU. Further, the eNB or the RSU can become a representative. In this case, the eNB or the RSU may set itself as a representative or may be set as a representative from the core network side. In particular, in the case of a node (a small cell, a UE type RSU, or the like) existing under the eNB, it is possible to performs the settings from the eNB side.

Upon receiving a response from the representative, the eNB or the RSU transmits information indicating that the representative UE is assigned to the other UEs.

The representative performs a setting of sensing and performs sensing. Further, the representative transmits a sensing result to the UE which is not the representative.

The eNB or the RSU determines whether or not liberation of the representative and reassignment of the representative are performed. In a case in which the liberation of the representative UE is performed, the eNB or the RSU transmits a liberation message to the current representative. The representative transmits ACK or NACK to the liberation message to the eNB or the RSU.

Then, the eNB or the RSU transmits information indicating that the representative is liberated to the other UEs, and transmits the message indicating that it is assigned as the representative to another node. The representative transmits ACK or NACK to the message indicating that it is assigned as the representative to the eNB or the RSU. Upon receiving the response from the representative, the eNB or the RSU transmits information indicating that the representative is assigned to other UEs.

A second method is a method in which the UE decides one or more representative UEs performing sensing. <FIG> is a flowchart illustrating an operation example of the eNB or the RSU, a node performing sensing as a representative, and other UEs in a case in which centralization of sensing is performed.

The eNB or the RSU specifies a condition for representing the sensing and transmits information of the setting of the representative to the UE.

Upon receiving the information of the setting of the representative from the eNB or the RSU, the UE decides the representative on the basis of the information and transmits the message indicating that it is assigned as the representative to the node decided as the representative. The representative that has received the message indicating that it is assigned as the representative transmits ACK or NACK.

The UE can determine whether or not the liberation of the representative and the reassignment of the representative are performed. In a case in which the liberation of the representative is performed, the UE transmits a liberation message to the current representative. The representative transmits ACK or NACK to the liberation message to the UE.

Then, the UE transmits information indicating that the representative is liberated to the other UEs, and transmits the message indicating that it is assigned as the representative to another node. The representative transmits ACK or NACK to the message indicating that it is assigned as the representative to the UE. Upon receiving the response from the representative, the UE transmits information indicating that the representative UE is assigned to other UEs.

For example, there is candidacy for the representative as a setting of the condition for representing which is executed by eNB or the RSU. The eNB may be a representative for sensing, the RSU may be a representative for sensing, and the UE may be a representative for sensing.

For example, as a method of deciding the representative UE, the eNB, the RSU, or the UE may decide the representative UE randomly from UEs located in a predetermined area for a predetermined period of time or may decide the representative UE on the basis of a predetermined rule. As the predetermined rule, for example, the UE transmitting a synchronization signal may be the representative UE, or the representative UE may be decided on the basis of an ID of the UE, a position of the UE, a category of the UE, a battery state of the UE, a speed of the UE, mobility of the UE, a status of a buffer of the UE, or the like.

As the information of the setting of the representative, for example, in a case in which the UE decides the representative, information such as a method of determining the representative, a start time and a period in which it acts as the representative, and the sensing parameter may be included. The sensing parameter may include, for example, parameters such as the sensing mode, the sensing start time, the sensing period, and the sensing target. The sensing target may be LTE-V2X, DSRC, or the like. In a case in which the target is LTE-V2X and the UE, a list of UEs to be sensed may be provided.

The liberation of the representative may be performed, for example, in a case in which the current representative is unable to perform the sensing. For example, the liberation of the representative may be performed in a case in which the sensing function is stopped in the eNB or the RSU or in a case in which the UE enters the idle state, is requested to reduce power consumption, deviates from the coverage of the current eNB, or does not function as the current RSU.

The reassignment of the representative may be performed promptly after the liberation of the representative or may be performed at a position at which a value of a timer reaches a next assignment timing.

For ACK or NACK, the representative transmits ACK when the assignment or liberation request is transmitted to the representative. If NACK is returned or there is no response until a response deadline, a new representative can be assigned.

If ACK is received after the representative assignment message, other UEs are notified of at least an ID of the representative. If ACK is received after the representative liberation message, other UEs are notified that the current representative is liberated.

Other nodes may assist the sensing instead of the UE. The eNB monitors the resource use situation and the sensing of all the UEs located within the coverage. In this case, the eNB collects measurement reports of a wireless situation from the UEs located within the coverage.

Further, the RSU also monitors the resource use situation and the sensing of neighboring UEs.

One or more representative UEs perform sensing for all other neighboring UEs. The eNB decides a UE performing sensing as the representative randomly or by a predetermined method. The predetermined method may be, for example, a method of selecting a terminal with a high SA reception capability (such as a terminal equipped with an advanced receiver) or a method of selecting a UE that does not care about power consumption even when the energy sensing is used.

Further, the RSU may decide the UE performing the sensing as the representative randomly or in a predetermined method.

Further, the UE also decides the representative either randomly, decides the UE transmitting the synchronization signal or decides the representative on the basis of the ID of the UE.

The representative UE can be liberated in a case in which the current representative UE is unable to perform the sensing. The representative UE is unable to perform the sensing, for example, in a case in which the status of the UE changes from the connected state to the idle state, in a case in which the UE desires to reduce power consumption, in a case in which the UE deviates from the coverage of the current eNB, or in a case in which the UE does not function as the current RSU. Further, in a case in which a timer of the sensing period is set, and the sensing period ends, the representative UE can be liberated. When the sensing period ends, the eNB or the RSU may decide to perform the liberation, or the UE may perform the sensing one after another.

At the time of reassignment, for example, a new UE may be selected randomly or may be selected by a predetermined method. Further, the reassignment may be performed immediately after the liberation or may be performed after a certain period of time.

When sensing + LBT (Listen before Talk) is introduced, it is possible to perform transmission with less collision while maintaining fairness among users. On the other hand, the LBT is a scheme adopted in the WiFi system, but it is difficult to handle unique traffic and it is difficult to apply it without change in V2X communication supported by the base station. Therefore, enhancement of the LBT is necessary for the LTE V2X communication. Further, the sensing scheme here is not limited to the energy sensing, and the SA decoding, the data decoding scheme, or the like may be used.

A selection method of selecting the LBT scheme in accordance with a traffic type will be described. In V2X communication, there are a periodical traffic in which the latency requirements are not strict and an event trigger traffic in which latency requirements are strict.

Particularly in the case of the event trigger traffic with the strict latency requirements, a standby time of a back-off time of the LBT is latency, and communication requirements may be unable to be satisfied.

In this regard, in the present embodiment, two LBT schemes will be described.

This is an LBT with a back-off timer. Transmission conditions of the transmission terminal are as follows.

This is an LBT with no back-off timer. Transmission conditions of the transmission terminal are as follows.

A threshold value of the sensing may be set separately in Type <NUM> and Type <NUM>. Further, the threshold value may be set separately for each channel such as the PSCCH or the PSSCH. A method of switching the LBT scheme in accordance with the traffic type to be transmitted is proposed. <FIG> is a flowchart illustrating a method of switching the LBT scheme. If the traffic to be transmitted is traffic with the strict latency requirements, for example, the event trigger traffic, it is transmitted in Type <NUM>, and otherwise it is transmitted in Type <NUM>. Further, the LBT scheme may be switched in accordance with a resource use situation (a traffic congestion situation). After the sensing, in a case in which available resources are tight, the probability of selecting the same resource as the neighboring terminal is high. To avoid this, the terminal switches the LBT scheme in accordance with the resource congestion degree. For example, in a case in which the sensing is performed, and a selectable resource amount is equal to or less than a certain threshold value, the terminal determines that incompatibility of resource selection with other terminals occurs and can operate to avoid the incompatibility by selecting the LBT scheme.

In addition to the traffic type and the resource use situation, a terminal category, a terminal ID, priority information of traffic, a speed of the terminal, or the like may be used as the information used to switch the LBT, and the LBT scheme may be switched in accordance with such information.

For a method of switching the LBT type, an arbitrary LBT scheme is notified from the base station. The notification may be given for each UE or for each cell. A mapping table of the LBT scheme and information used for switching may be provided from the base station to the terminal, or the terminal side may select the LBT type in accordance with the information used for switching. The method of switching the LBT type may be set in the terminal in advance.

In V2X communication, a case in which the operation is carried out while performing co-existence with the DSRC system (<NUM>. 11p communication) is assumed. In this case, in the LTE V2X communication, it is necessary to detect the DSRC system and perform the operation not to give interference. At the same time, it is necessary to avoid packet collision with other users even within the LTE V2X communication.

Therefore, in the present embodiment, DSRC_LBT for DSRC system detection is introduced. DSRC_LBT may be Type <NUM> or Type <NUM>, but Type <NUM> is preferable.

Further, in the present embodiment, LTE_V2X_LBT for mode <NUM> communication packet collision avoidance in the LTE V2X system is introduced. LTE_V2X_LBT may be Type <NUM> or Type <NUM>, but Type <NUM> is preferable.

Further, in addition to LTE_V2X_LBT, other sensing methods such as the SA decoding may be used.

<FIG> is a flowchart illustrating the flow of <NUM>-step sensing at the terminal. The terminal executes DSRC_LBT, executes LTE_V2X_LBT after the channel state is determined as IDLE. Then, in a case in which the channel state is determined to be IDLE by LTE_V2X_LBT, a signal is transmitted.

The terminal may change an area in which the sensing is performed through DSRC_LBT and LTE_V2X_LBT. Further, the terminal may change the area in the frequency direction, change the area in the time direction, or change the area in both the frequency direction and the time direction. The sensing area may be notified from the base station in advance or may be preset at the terminal.

In V2X communication, unlike the WiFi system, there is a central control station such as the base station. In this regard, a method of setting the back-off timer of the LBT is necessary.

In the present embodiment, the back-off timer is set from the base station to the terminal. As the notification method from the base station to the terminal, the notification may be given through an RRC, a DCI, an SIB, signaling, or other methods.

A value of the back-off timer may be a back-off timer in the time direction, a back-off timer in the frequency direction, or back-off timers in both the time direction and the frequency direction. In the case of the back-off timer in the frequency direction, a band may be divided into a plurality of subcarriers, divided by the number of subcarriers used for its own transmission, or uniquely divided by a system. Further, the value of the back-off timer may be a sum of the back-off timers in both the time direction and the frequency direction. Further, an effective period of the back-off timer may be set from the base station to the terminal. Further, the back-off timer may be set over a plurality of scheduling periods.

In a case in which a back-off timer table is provided from base station to the terminal, information in which the value of the back-off timer, the back-off timer in the time direction, the back-off timer in the frequency direction, and the back-off timers in both the time direction and the frequency direction are added may be provided.

<FIG> is a flowchart illustrating an example of the back-off operation. The back-off may be set in the time direction or in the frequency direction. Further, the back-off may be set in both the time direction and in the frequency direction.

The terminal performs sensing at a designated time or in a frequency area, determines whether or not there is still a sensing area in the frequency direction if occupation is detected, slides in the frequency direction if there is still a sensing area in the frequency direction, and resets the frequency direction by sliding in the time direction if there is no sensing area in the frequency direction. In a case in which no occupation is detected, the terminal performs back-off subtraction to be described later. The back-off may be configured with any one of a subframe unit, a subcarrier unit, and an SA period unit or may be configured with a combination thereof.

The terminal sets the back-off timer in a case in which a specific back-off timer is notified of. In a case in which the back-off timer is set with a width, the terminal randomly selects from the width.

Further, in a case in which a table is provided, the terminal selects the back-off timer depending on an associated parameter. In a case in which the back-off timer is set with a width, it is randomly selected from the width.

The terminal subtracts the back-off value in accordance with a sensing result. The terminals can perform subtraction in each of the time direction and the frequency direction. In a case in which the back-off is set in each of a time and frequency, the terminal performs subtraction in each of a time and frequency. In a case in which it is a common back-off, the terminal subtracts one if a non-occupation is detected regardless of a time and a frequency.

<FIG> is a flowchart illustrating a method of setting the sensing area. For example, as a method of sliding a time and a frequency, there is a method such as a method of first sliding in the time direction and then sliding in the frequency direction.

In sensing + LBT, transmission is performed after transmission authority is acquired. In the case of TDM, since the SA pool and the data pool are divided in the time axis, it is necessary to newly set the conditions for transmission authority acquisition. For example, even when the transmission authority for the SA resources is acquired, transmission is unable to be performed unless the data area resources can be secured. The reverse is also true. As described above, it is necessary to newly specify the conditions for transmission authority acquisition. Here, three methods are described below.

It is a method in which the transmission terminal acquires the transmission authority for SA and data at a stage at which the sensing is performed on only the SA area, and the transmission authority for the SA is acquired. Since sensing of the data part is not performed, collision of the data part may occur. Since sensing of at least the SA is performed, it is better than not doing anything.

The transmission authority acquisition condition is assumed to be when SA_LBT is OK. If the rest of the SA resources is equal to or more than a certain value, the SA resources are randomly selected from the remaining SA pool, the data resources randomly selected from the data pool, and transmission is performed.

If the rest of the SA resources is equal to or less than a certain value, the transmission is postponed up to the next SA period. The SA resources are selected from the SA resource pool in the next SA period randomly or on the basis of the result of SA_LBT, the data resources are randomly selected from the data pool, and transmission is performed.

<FIG> is a flowchart illustrating a method of determining whether or not it is possible to acquire the transmission authority with only the SA.

If the transmission side terminal desires to transmit a packet, the transmission side terminal sets SA_LBT=N and starts the sensing. N is a counter, and N is decremented by <NUM> if an SA channel is idle.

If N becomes <NUM> in subframe SFSA_LBTend, SA_LBT=<NUM>. The terminal determines whether or not there are sufficient SA resources in the corresponding SA period by comparing it with the available subframe SFavailable which is a parameter preset by the base station.

If the SA resources are sufficient, the terminal randomly selects the SA resources from the SA resource pool. If there are no SA resources, the terminal postpones transmission up to the next SA period. The SA resources are selected from the SA resource pool randomly in the next SA period or on the basis of the result of SA_LBT, the data resources are randomly selected from the data pool, and transmission is performed. Here, in a case in which transmission is performed in a next or later SA period, the terminal may subtract the back-off value by a certain amount in order to increase the priority of the transmission opportunity acquisition.

It is a method in which the transmission terminal acquires the transmission authority for SA and data at a stage at which the sensing is performed on only the data area, and the transmission authority for the data is acquired. Since the sensing of the SA part is not performed, the collision of the SA part may occur. Since sensing of at least the data part is performed, it is better than not doing anything.

The transmission authority acquisition condition is assumed to be when Data_LBT is OK. If the rest of the data resources in the corresponding SA period is equal to or more than a certain value, the data resources are reserved from the rest. The terminal randomly selects the SA resources from the SA resource pool in the next SA period, selects the reserved data resources from the data pool, and performs transmission.

If the rest of the data resources is equal to or less than a certain value, transmission is postponed up to the next SA period. The SA resources are randomly selected from the SA resource pool in the next SA period, the data resources are selected from the data pool randomly or on the basis of the result of DATA_LBT, and transmission is performed.

<FIG> is a flowchart illustrating an operation example of acquiring transmission authority for the SA and the data in a case in which the transmission resource of the data can be secured. If the transmission side terminal desires to transmit a packet, the transmission side terminal sets DATA_LBT=N and start the sensing. N is a counter, and N is decremented by <NUM> if an SA channel is idle.

If N becomes <NUM>, the terminal determines whether or not there are sufficient data resources in the corresponding SA period by comparing it with the available subframe SFavailable which is a parameter preset by the base station.

If there are data resources, the data resources are reserved from the rest. The terminal randomly selects the SA resources from the SA resource pool in the next SA period, selects the reserved data resources from the data pool, and performs transmission.

If there are no data resources, transmission is postponed up to the next SA period. The SA resources are randomly selected from the SA resource pool in the next SA period, the data resources are selected randomly or on the basis of the result of DATA_LBT from the data pool, and transmission is performed.

The transmission terminal performs sensing of both the SA area and the data area. The LBT is applied only to the SA, and reservation is newly introduced for the data. Because sensing of both the SA and the data is performed, the probability of collision is lower than the above two methods.

The transmission authority acquisition condition is assumed to be when SA_LBT is OK, and the resources of the data area are "Reserved. " If the rest of the SA resources is equal to or less than a certain value, the transmission is postponed up to the next SA period.

<FIG> is a flowchart illustrating an operation example of acquiring the transmission authority for the SA and the data are acquired in a case in which transmission resources of both the SA and the data can be secured.

In a case in which the transmission authority for the SA is acquired, but the data resources are not secured (<FIG>), whether or not the transmission authority for the SA is acquired, a method of acquiring transmission authority for the SA and the data in a case in which the transmission resources of the SA can be secured is executed.

The data pool performs sensing with no LBT, and resources to be used are reserved. It is determined whether or not the reserved data resources are used in accordance with the result of SA_LBT.

In a case in which the data resources are reserved, but the transmission authority for the SA is not acquired (<FIG>), the data resources are secured by reserving resources to be used using sensing with no LBT.

If the terminal performs SA_LBT and acquires the transmission authority, the resources of the current SA period are selected with reference to the reserved data resources of the previous SA period. If the rest of SA resources is equal to or less than a certain value, the terminal postpones transmission up to the next SA period.

Next, an example will be described in detail.

The UE should be present within the coverage of the eNB. The eNB sets up the resource pool and indicates resource allocation for all UEs. <FIG> is an explanatory diagram illustrating a resource allocation example in the mode <NUM>.

The UE may be within or outside the coverage of the eNB. In a case in which the UE is outside the coverage, the resource pool should be preset. The UE randomly selects resources from the resource pool. <FIG> is an explanatory diagram illustrating a resource allocation example in the mode <NUM>.

In the UE, the time interval of sensing may be restricted. <FIG> is an explanatory diagram illustrating an example in which the time interval of sensing in TDM is restricted. The UE is informed of the time interval for sensing by way of, for example, {(SF1, SF2), (SF3, SF4), and (SF4, SF5)} in <FIG>.

Further, in the UE, the frequency band of sensing may be restricted. <FIG> is an explanatory diagram illustrating an example in which the frequency band of sensing in TDM is restricted. The UE is informed of the frequency band for sensing by way of, for example, SA{(F1, F2)} and data{(F3, F4)} in <FIG>.

In the UE, both the time interval and the frequency band of sensing may be restricted. <FIG> is an explanatory diagram illustrating an example in which both the time interval and the frequency band of sensing in TDM are restricted. The UE is informed of the time interval and the frequency band for sensing by way of, for example, {(SF1, SF2), (SF3, SF4), (SF4, SF5)}, SA{(F1, F2)}, and data{(F3, F4)} in <FIG>.

In the UE, a block of sensing may be restricted. The pool is partitioned, and each pool is given a block ID. <FIG> is an explanatory diagram illustrating an example in which the block of sensing in TDM is restricted. The UE is informed of the block ID for sensing in units of block by way of, for example {s4, d2, d5} in <FIG>.

In the UE, the time interval of sensing may be restricted. <FIG> is an explanatory diagram illustrating an example in which the time interval of sensing in FDM is restricted. The UE is informed of the time interval for sensing by way of, for example, {(SF1, SF2), (SF3, SF4), and (SF4, SF5)} in <FIG>.

Further, in the UE, the frequency band of sensing may be restricted. <FIG> is an explanatory diagram illustrating an example in which the frequency band of sensing in FDM is restricted. The UE is informed of the frequency band for sensing by way of, for example, {(F1, F2)} and {(F3, F4)} in <FIG>.

In the UE, both the time interval and the frequency band of sensing may be restricted. <FIG> is an explanatory diagram illustrating an example in which both the time interval and the frequency band of sensing in FDM are restricted. The UE is informed of the time interval and the frequency band for sensing by way of, for example, SA{(SF1, SF2)}, {(SF3, SF4)}, data{(SF4, SF5)}, and {(F1, F2), (F3, F4)} in <FIG>.

In the UE, a block of sensing may be restricted. The pool is partitioned, and each pool is given a block ID. <FIG> is an explanatory diagram illustrating an example in which the block of sensing in FDM is restricted. The UE is informed of the block ID for sensing in units of block by way of, for example {s4, d4} in <FIG>.

<FIG> is an explanatory diagram illustrating an example in which the eNB performs the sensing.

<FIG> is an explanatory diagram illustrating an example in which the RSU performs the sensing.

<FIG> is an explanatory diagram illustrating an example in which the representative UE performs the sensing. <FIG> illustrates an example in which the eNB assigns one or more UEs as a UE performing the sensing.

<FIG> is an explanatory diagram illustrating an example in which the representative UE performs the sensing. <FIG> illustrates an example in which the RSU assigns one or more UEs as a UE performing the sensing.

<FIG> is an explanatory diagram illustrating an example in which the representative UE performs the sensing. <FIG> illustrates an example in which the UE decides the representative UE, for example, using UEid. <FIG> illustrates an example in which the UE with Id=<NUM> is decided as the representative UE.

For example, the representative UE may be liberated in a case in which the state of the UE changes from the connected state to the idle state. <FIG> is an explanatory diagram illustrating an example in which the representative UE is liberated in a case in which the state of the UE changes from the connected to the idle.

Further, for example, the representative UE may be liberated in a case in which it is separated from the current eNB or the RSU. <FIG> is an explanatory diagram illustrating an example in which the representative UE is liberated in a case in which it is separated from the current eNB. Further, <FIG> is an explanatory diagram illustrating an example in which the representative UE is liberated in a case in which it is separated from the current RSU.

A new assignment of the representative UE can be performed using, for example, a predetermined timer. <FIG> is an explanatory diagram illustrating an example of a new assignment of the representative UE using a timer.

A new assignment of the representative UE can also be performed, for example, by the representative UE performing the sensing in order using a predetermined timer. <FIG> is an explanatory diagram illustrating an example in which the representative UE performs the sensing in order using a predetermined timer.

In a subframe SF0, in the transmission terminal, the counter N is set <NUM>. The terminal starts the sensing from a next subframe SF1. It is assumed that as a result of sensing, it is determined that there is a margin in resources in subframes SF1 to SF3, there is no margin in resources in subframes SF4 to SF5, and there is a margin in resources in subframes SF6 to SF7.

In the subframes SF1 to SF3, since there are three subframes that have extra resources, the counter N is subtracted from <NUM> to <NUM>.

In the subframes SF4 to SF5, since there is no margin in resources, the value of the counter N does not change.

In the subframes SF6 to SF7, since there are three subframes that have enough resources, the counter N is decremented from <NUM> to <NUM>. Therefore, the terminal selects the resources in the next subframe SF8 and transmits the packet.

In the subframe SF0, in the transmission terminal, the counter N is set <NUM>. The terminal is on standby for five subframes, then selects the resources in the next subframe, and transmits the packet.

(<NUM>) Only transmission authority for SA is determined. As a condition, a subframe offset is set to <NUM>. A first example is a case in which the counter N becomes <NUM>, the transmission authority is acquired, and the number of remaining subframes is four which is larger than the subframe offset. <FIG> is an explanatory diagram illustrating an enhanced LBT. In this case, the UE randomly selects the SA resources from the remaining SA pool and the data pool in the current SA period.

A second example is a case in which the counter N becomes <NUM>, the transmission authority is acquired, and the number of remaining subframes is one which is smaller than the subframe offset. <FIG> is an explanatory diagram illustrating an enhanced LBT. In this case, the UE randomly selects the SA resources and the data resources from the SA pool and the data pool in the next SA period.

A third example is a case in which counter N becomes <NUM>, the transmission authority is acquired, and the number of remaining subframes is one which is smaller than subframe offset. <FIG> is an explanatory diagram illustrating an enhanced LBT. In this case, the UE selects the SA resources on the basis of the result of SA_LBT in the SA pool and the data pool in the next SA period, and randomly selects the data resources.

As a condition, the subframe offset is set to <NUM>. A first example is a case in which the counter N becomes <NUM>, the transmission authority is acquired, and the number of remaining subframes is <NUM> which is larger than the subframe offset. <FIG> is an explanatory diagram illustrating an enhanced LBT. In this case, the UE randomly selects the SA resources from the SA pool in the next SA period and selects the data resources from the reserved data pool.

A third example is a case in which counter N becomes <NUM>, the transmission authority is acquired, and the number of remaining subframes is one which is smaller than subframe offset. <FIG> is an explanatory diagram illustrating an enhanced LBT. In this case, the UE selects the SA resources from the SA pool in the next SA period, and selects the SA resources from the result of DATA_LBT in the data pool.

As a condition, the subframe offset is set to <NUM>. <FIG> is an explanatory diagram illustrating an enhanced LBT. A first example is a case in which the transmission authority for the SA is acquired, but the data resources are not secured. In this case, the UE reserves the data resources in the current SA period and randomly selects the data resources from the SA pool and the data pool in the next SA period.

<FIG> is an explanatory diagram illustrating an enhanced LBT. A second example is a case in which the data resources are secured, but the transmission authority for the SA is not acquired. In this case, when the transmission authority is acquired, the UE randomly selects the SA resources from the current SA pool and the reserved data pool with reference to a situation of an immediately previous SA period.

Next, an example of a configuration of a base station (eNB) <NUM> according to an embodiment of the present disclosure will be described with reference to <FIG> is a block diagram illustrating an example of the configuration of the base station <NUM> according to an embodiment of the present disclosure. Referring to <FIG>, a base station <NUM> includes an antenna unit <NUM>, a wireless communication unit <NUM>, a network communication unit <NUM>, a storage unit <NUM>, and a processing unit <NUM>.

The antenna unit <NUM> radiates a signal output from the wireless communication unit <NUM> to the space as a radio wave. Further, the antenna unit <NUM> converts a radio wave in the space into a signal, and outputs the signal to the wireless communication unit <NUM>.

The wireless communication unit <NUM> performs transmission and reception of signals. For example, the wireless communication unit <NUM> transmits a downlink signal to the terminal device and receives an uplink signal from the terminal device.

The network communication unit <NUM> performs transmission and reception of information. For example, the network communication unit <NUM> transmits information to other nodes and receives information from other nodes. For example, other node includes another base station and a core network node.

The storage unit <NUM> temporarily or permanently stores a program for the operation of the base station <NUM> and various data.

The processing unit <NUM> provides various functions of the base station <NUM>. The processing unit <NUM> includes a transmission processing unit <NUM> and a notification unit <NUM>. Further, the processing unit <NUM> may further include components other than these constituent elements. That is, the processing unit <NUM> may also perform an operation other than the operations of these components.

The transmission processing unit <NUM> executes a process related to transmission of data to be transmitted to a terminal device <NUM>. The transmission processing unit <NUM> executes a general process of the base station (eNB). Further, the notification unit <NUM> executes a process related to notification of information to the terminal device <NUM>. The notification unit <NUM> executes a general notification process for the terminal device of the base station (eNB).

Next, an example of a configuration of the terminal device <NUM> according to an embodiment of the present disclosure will be described with reference to <FIG> is a block diagram illustrating an example of the configuration of the terminal device <NUM> according to an embodiment of the present disclosure. Referring to <FIG>, the terminal device <NUM> includes an antenna unit <NUM>, a wireless communication unit <NUM>, a storage unit <NUM>, and a processing unit <NUM>.

The wireless communication unit <NUM> performs transmission and reception of signals. For example, the wireless communication unit <NUM> receives a downlink signal from the base station and transmits an uplink signal to the base station.

The storage unit <NUM> temporarily or permanently stores a program for the operation of the terminal device <NUM> and various data.

The processing unit <NUM> provides various functions of the terminal device <NUM>. The processing unit <NUM> includes an acquisition unit <NUM> and a reception processing unit <NUM>. Further, the processing unit <NUM> may further include other components than these constituent elements. That is, the processing unit <NUM> may also perform an operation other than the operations of these components.

The acquisition unit <NUM> executes a process related to acquisition of data transmitted from the base station <NUM>. The reception processing unit <NUM> executes a process related to reception of data acquired by the acquisition unit <NUM>. The reception processing unit <NUM> executes a general process of the terminal device described above.

The technology of the present disclosure can be applied to various products. The base station <NUM> may be realized as any type of evolved node B (eNB), for example, a macro eNB, a small eNB, or the like. A small eNB may be an eNB that covers a smaller cell than a macro cell, such as a pico eNB, a micro eNB, or a home (femto) eNB. Alternatively, the base station <NUM> may be realized as another type of base station such as a node B or a base transceiver station (BTS). The base station <NUM> may include a main body that controls radio communication (also referred to as a base station device) and one or more remote radio heads (RRHs) disposed in a different place from the main body. In addition, various types of terminals to be described below may operate as the base station <NUM> by temporarily or semi-permanently executing the base station function.

In addition, the terminal device <NUM> may be realized as, for example, a mobile terminal such as a smartphone, a tablet personal computer (PC), a notebook PC, a portable game terminal, a portable/dongle type mobile router, or a digital camera, or an in-vehicle terminal such as a car navigation device. In addition, the terminal device <NUM> may be realized as a terminal that performs machine-to-machine (M2M) communication (also referred to as a machine type communication (MTC) terminal). Furthermore, the terminal device <NUM> may be a wireless communication module mounted in such a terminal (for example, an integrated circuit module configured in one die).

<FIG> is a block diagram illustrating a first example of a schematic configuration of an eNB to which the technology of the present disclosure may be applied. An eNB <NUM> includes one or more antennas <NUM> and a base station device <NUM>. Each antenna <NUM> and the base station device <NUM> may be connected to each other via an RF cable.

Each of the antennas <NUM> includes a single or multiple antenna elements (such as multiple antenna elements included in an MIMO antenna), and is used for the base station device <NUM> to transmit and receive radio signals. The eNB <NUM> may include the multiple antennas <NUM>, as illustrated in <FIG>. For example, the multiple antennas <NUM> may be compatible with multiple frequency bands used by the eNB <NUM>. Although <FIG> illustrates the example in which the eNB <NUM> includes the multiple antennas <NUM>, the eNB <NUM> may also include a single antenna <NUM>.

The base station device <NUM> includes a controller <NUM>, a memory <NUM>, a network interface <NUM>, and a wireless communication interface <NUM>.

The controller <NUM> may be, for example, a CPU or a DSP, and operates various functions of a higher layer of the base station device <NUM>. For example, the controller <NUM> generates a data packet from data in signals processed by the wireless communication interface <NUM>, and transfers the generated packet via the network interface <NUM>. The controller <NUM> may bundle data from multiple base band processors to generate the bundled packet, and transfer the generated bundled packet. The controller <NUM> may have logical functions of performing control such as radio resource control, radio bearer control, mobility management, admission control, and scheduling. The control may be performed in corporation with an eNB or a core network node in the vicinity. The memory <NUM> includes RAM and ROM, and stores a program that is executed by the controller <NUM>, and various types of control data (such as a terminal list, transmission power data, and scheduling data).

The network interface <NUM> is a communication interface for connecting the base station device <NUM> to a core network <NUM>. The controller <NUM> may communicate with a core network node or another eNB via the network interface <NUM>. In this case, the eNB <NUM> may be connected to a core network node or another eNB through a logical interface (e.g. S1 interface or X2 interface). The network interface <NUM> may also be a wired communication interface or a wireless communication interface for wireless backhaul. If the network interface <NUM> is a wireless communication interface, the network interface <NUM> may use a higher frequency band for wireless communication than a frequency band used by the wireless communication interface <NUM>.

The wireless communication interface <NUM> supports any cellular communication scheme such as Long Term Evolution (LTE) and LTE-Advanced, and provides radio connection to a terminal positioned in a cell of the eNB <NUM> via the antenna <NUM>. The wireless communication interface <NUM> may typically include, for example, a baseband (BB) processor <NUM> and an RF circuit <NUM>. The BB processor <NUM> may perform, for example, encoding/decoding, modulating/demodulating, and multiplexing/demultiplexing, and performs various types of signal processing of layers (such as L1, medium access control (MAC), radio link control (RLC), and a packet data convergence protocol (PDCP)). The BB processor <NUM> may have a part or all of the above-described logical functions instead of the controller <NUM>. The BB processor <NUM> may be a memory that stores a communication control program, or a module that includes a processor and a related circuit configured to execute the program. Updating the program may allow the functions of the BB processor <NUM> to be changed. The module may be a card or a blade that is inserted into a slot of the base station device <NUM>. Alternatively, the module may also be a chip that is mounted on the card or the blade. Meanwhile, the RF circuit <NUM> may include, for example, a mixer, a filter, and an amplifier, and transmits and receives radio signals via the antenna <NUM>.

The wireless communication interface <NUM> may include the multiple BB processors <NUM>, as illustrated in <FIG>. For example, the multiple BB processors <NUM> may be compatible with multiple frequency bands used by the eNB <NUM>. The wireless communication interface <NUM> may include the multiple RF circuits <NUM>, as illustrated in <FIG>. For example, the multiple RF circuits <NUM> may be compatible with multiple antenna elements. Although <FIG> illustrates the example in which the wireless communication interface <NUM> includes the multiple BB processors <NUM> and the multiple RF circuits <NUM>, the wireless communication interface <NUM> may also include a single BB processor <NUM> or a single RF circuit <NUM>.

In the eNB <NUM> shown in <FIG>, one or more constituent elements (the transmission processing unit <NUM> and /or the notification unit <NUM>) included in the processing unit <NUM> described with reference to <FIG> may be implemented by the wireless communication interface <NUM>. Alternatively, at least some of these constituent elements may be implemented by the controller <NUM>. As an example, a module which includes a part (for example, the BB processor <NUM>) or all of the wireless communication interface <NUM> and/or the controller <NUM> may be mounted in the eNB <NUM>, and the above-described one or more constituent elements may be implemented by the module. In this case, the module may store a program for causing the processor to function as the above-described one or more constituent elements (i.e., a program for causing the processor to execute operations of the one or more constituent elements) and may execute the program. As another example, the program for causing the processor to function as the above-described one or more constituent elements may be installed in the eNB <NUM>, and the wireless communication interface <NUM> (for example, the BB processor <NUM>) and/or the controller <NUM> may execute the program. As described above, the eNB <NUM>, the base station device <NUM> or the module may be provided as a device which includes the one or more constituent elements, and the program for causing the processor to function as the above-described one or more constituent elements may be provided. In addition, a readable recording medium in which the program is recorded may be provided.

In addition, in the eNB <NUM> shown in <FIG>, the wireless communication unit <NUM> described with reference to <FIG> may be implemented by the wireless communication interface <NUM> (for example, the RF circuit <NUM>). Further, the antenna unit <NUM> may be implemented by the antenna <NUM>. Moreover, the network communication unit <NUM> may be implemented by the controller <NUM> and/or the network interface <NUM>. Further, the storage unit <NUM> may be implemented by the memory <NUM>.

<FIG> is a block diagram illustrating a second example of a schematic configuration of an eNB to which the technology of the present disclosure may be applied. An eNB <NUM> includes one or more antennas <NUM>, a base station device <NUM>, and an RRH <NUM>. Each antenna <NUM> and the RRH <NUM> may be connected to each other via an RF cable. The base station device <NUM> and the RRH <NUM> may be connected to each other via a high speed line such as an optical fiber cable.

Each of the antennas <NUM> includes a single or multiple antenna elements (such as multiple antenna elements included in an MIMO antenna), and is used for the RRH <NUM> to transmit and receive radio signals. The eNB <NUM> may include the multiple antennas <NUM>, as illustrated in <FIG>. For example, the multiple antennas <NUM> may be compatible with multiple frequency bands used by the eNB <NUM>. Although <FIG> illustrates the example in which the eNB <NUM> includes the multiple antennas <NUM>, the eNB <NUM> may also include a single antenna <NUM>.

The base station device <NUM> includes a controller <NUM>, a memory <NUM>, a network interface <NUM>, a wireless communication interface <NUM>, and a connection interface <NUM>. The controller <NUM>, the memory <NUM>, and the network interface <NUM> are the same as the controller <NUM>, the memory <NUM>, and the network interface <NUM> described with reference to <FIG>.

The wireless communication interface <NUM> supports any cellular communication scheme such as LTE and LTE-Advanced, and provides wireless communication to a terminal positioned in a sector corresponding to the RRH <NUM> via the RRH <NUM> and the antenna <NUM>. The wireless communication interface <NUM> may typically include, for example, a BB processor <NUM>. The BB processor <NUM> is the same as the BB processor <NUM> described with reference to <FIG>, except the BB processor <NUM> is connected to the RF circuit <NUM> of the RRH <NUM> via the connection interface <NUM>. The wireless communication interface <NUM> may include the multiple BB processors <NUM>, as illustrated in <FIG>. For example, the multiple BB processors <NUM> may be compatible with multiple frequency bands used by the eNB <NUM>. Although <FIG> illustrates the example in which the wireless communication interface <NUM> includes the multiple BB processors <NUM>, the wireless communication interface <NUM> may also include a single BB processor <NUM>.

The connection interface <NUM> is an interface for connecting the base station device <NUM> (wireless communication interface <NUM>) to the RRH <NUM>. The connection interface <NUM> may also be a communication module for communication in the above-described high speed line that connects the base station device <NUM> (wireless communication interface <NUM>) to the RRH <NUM>.

The RRH <NUM> includes a connection interface <NUM> and a wireless communication interface <NUM>.

The connection interface <NUM> is an interface for connecting the RRH <NUM> (wireless communication interface <NUM>) to the base station device <NUM>. The connection interface <NUM> may also be a communication module for communication in the above-described high speed line.

The wireless communication interface <NUM> transmits and receives radio signals via the antenna <NUM>. The wireless communication interface <NUM> may typically include, for example, the RF circuit <NUM>. The RF circuit <NUM> may include, for example, a mixer, a filter, and an amplifier, and transmits and receives radio signals via the antenna <NUM>. The wireless communication interface <NUM> may include multiple RF circuits <NUM>, as illustrated in <FIG>. For example, the multiple RF circuits <NUM> may support multiple antenna elements. Although <FIG> illustrates the example in which the wireless communication interface <NUM> includes the multiple RF circuits <NUM>, the wireless communication interface <NUM> may also include a single RF circuit <NUM>.

In the eNB <NUM> shown in <FIG>, one or more constituent elements (the transmission processing unit <NUM> and /or the notification unit <NUM>) included in the processing unit <NUM> described with reference to <FIG> may be implemented by the wireless communication interface <NUM> and/or the wireless communication interface <NUM>. Alternatively, at least some of these constituent elements may be implemented by the controller <NUM>. As an example, a module which includes a part (for example, the BB processor <NUM>) or all of the wireless communication interface <NUM> and/or the controller <NUM> may be mounted in the eNB <NUM>, and the above-described one or more constituent elements may be implemented by the module. In this case, the module may store a program for causing the processor to function as the above-described one or more constituent elements (i.e., a program for causing the processor to execute operations of the one or more constituent elements) and may execute the program. As another example, the program for causing the processor to function as the above-described one or more constituent elements may be installed in the eNB <NUM>, and the wireless communication interface <NUM> (for example, the BB processor <NUM>) and/or the controller <NUM> may execute the program. As described above, the eNB <NUM>, the base station device <NUM> or the module may be provided as a device which includes the one or more constituent elements, and the program for causing the processor to function as the above-described one or more constituent elements may be provided. In addition, a readable recording medium in which the program is recorded may be provided.

In addition, in the eNB <NUM> shown in <FIG>, for example, the wireless communication unit <NUM> described with reference to <FIG> may be implemented by the wireless communication interface <NUM> (for example, the RF circuit <NUM>). Further, the antenna unit <NUM> may be implemented by the antenna <NUM>. Moreover, the network communication unit <NUM> may be implemented by the controller <NUM> and/or the network interface <NUM>. Further, the storage unit <NUM> may be implemented by the memory <NUM>.

<FIG> is a block diagram illustrating an example of a schematic configuration of a smartphone <NUM> to which the technology of the present disclosure may be applied. The smartphone <NUM> includes a processor <NUM>, a memory <NUM>, a storage <NUM>, an external connection interface <NUM>, a camera <NUM>, a sensor <NUM>, a microphone <NUM>, an input device <NUM>, a display device <NUM>, a speaker <NUM>, a wireless communication interface <NUM>, one or more antenna switches <NUM>, one or more antennas <NUM>, a bus <NUM>, a battery <NUM>, and an auxiliary controller <NUM>.

The processor <NUM> may be, for example, a CPU or a system on a chip (SoC), and controls functions of an application layer and another layer of the smartphone <NUM>. The memory <NUM> includes RAM and ROM, and stores a program that is executed by the processor <NUM>, and data. The storage <NUM> may include a storage medium such as a semiconductor memory and a hard disk. The external connection interface <NUM> is an interface for connecting an external device such as a memory card and a universal serial bus (USB) device to the smartphone <NUM>.

The camera <NUM> includes an image sensor such as a charge coupled device (CCD) and a complementary metal oxide semiconductor (CMOS), and generates a captured image. The sensor <NUM> may include a group of sensors such as a measurement sensor, a gyro sensor, a geomagnetic sensor, and an acceleration sensor. The microphone <NUM> converts sounds that are input to the smartphone <NUM> to audio signals. The input device <NUM> includes, for example, a touch sensor configured to detect touch onto a screen of the display device <NUM>, a keypad, a keyboard, a button, or a switch, and receives an operation or an information input from a user. The display device <NUM> includes a screen such as a liquid crystal display (LCD) and an organic light-emitting diode (OLED) display, and displays an output image of the smartphone <NUM>. The speaker <NUM> converts audio signals that are output from the smartphone <NUM> to sounds.

The wireless communication interface <NUM> supports any cellular communication scheme such as LTE and LTE-Advanced, and performs wireless communication. The wireless communication interface <NUM> may typically include, for example, a BB processor <NUM> and an RF circuit <NUM>. The BB processor <NUM> may perform, for example, encoding/decoding, modulating/demodulating, and multiplexing/demultiplexing, and performs various types of signal processing for wireless communication. Meanwhile, the RF circuit <NUM> may include, for example, a mixer, a filter, and an amplifier, and transmits and receives radio signals via the antenna <NUM>. The wireless communication interface <NUM> may also be a one chip module that has the BB processor <NUM> and the RF circuit <NUM> integrated thereon. The wireless communication interface <NUM> may include the multiple BB processors <NUM> and the multiple RF circuits <NUM>, as illustrated in <FIG>. Although <FIG> illustrates the example in which the wireless communication interface <NUM> includes the multiple BB processors <NUM> and the multiple RF circuits <NUM>, the wireless communication interface <NUM> may also include a single BB processor <NUM> or a single RF circuit <NUM>.

Furthermore, in addition to a cellular communication scheme, the wireless communication interface <NUM> may support another type of wireless communication scheme such as a short-distance wireless communication scheme, a near field communication scheme, and a wireless local area network (LAN) scheme. In that case, the wireless communication interface <NUM> may include the BB processor <NUM> and the RF circuit <NUM> for each wireless communication scheme.

Each of the antenna switches <NUM> switches connection destinations of the antennas <NUM> among multiple circuits (such as circuits for different wireless communication schemes) included in the wireless communication interface <NUM>.

Each of the antennas <NUM> includes a single or multiple antenna elements (such as multiple antenna elements included in an MIMO antenna), and is used for the wireless communication interface <NUM> to transmit and receive radio signals. The smartphone <NUM> may include the multiple antennas <NUM>, as illustrated in <FIG>. Although <FIG> illustrates the example in which the smartphone <NUM> includes the multiple antennas <NUM>, the smartphone <NUM> may also include a single antenna <NUM>.

Furthermore, the smartphone <NUM> may include the antenna <NUM> for each wireless communication scheme. In that case, the antenna switches <NUM> may be omitted from the configuration of the smartphone <NUM>.

The bus <NUM> connects the processor <NUM>, the memory <NUM>, the storage <NUM>, the external connection interface <NUM>, the camera <NUM>, the sensor <NUM>, the microphone <NUM>, the input device <NUM>, the display device <NUM>, the speaker <NUM>, the wireless communication interface <NUM>, and the auxiliary controller <NUM> to each other. The battery <NUM> supplies power to blocks of the smartphone <NUM> illustrated in <FIG> via feeder lines, which are partially shown as dashed lines in the figure. The auxiliary controller <NUM> operates a minimum necessary function of the smartphone <NUM>, for example, in a sleep mode.

In the smartphone <NUM> shown in <FIG>, one or more constituent elements (the acquisition unit <NUM> and/or the reception processing unit <NUM>) included in the processing unit <NUM> described with reference to <FIG> may be implemented by the wireless communication interface <NUM>. Alternatively, at least some of these constituent elements may be implemented by the processor <NUM> or the auxiliary controller <NUM>. As an example, a module which includes a part (for example, the BB processor <NUM>) or all of the wireless communication interface <NUM>, the processor <NUM> and/or the auxiliary controller <NUM> may be mounted in the smartphone <NUM>, and the above-described one or more constituent elements may be implemented by the module. In this case, the module may store a program for causing the processor to function as the above-described one or more constituent elements (i.e., a program for causing the processor to execute operations of the above-described one or more constituent elements) and may execute the program. As another example, the program for causing the processor to function as the above-described one or more constituent elements may be installed in the smartphone <NUM>, and the wireless communication interface <NUM> (for example, the BB processor <NUM>), the processor <NUM> and/or the auxiliary controller <NUM> may execute the program. As described above, the smartphone <NUM> or the module may be provided as a device which includes the one or more constituent elements, and the program for causing the processor to function as the above-described one or more constituent elements may be provided. In addition, a readable recording medium in which the program is recorded may be provided.

In addition, in the smartphone <NUM> shown in <FIG>, the wireless communication unit <NUM> described, for example, with reference to <FIG> may be implemented by the wireless communication interface <NUM> (for example, the RF circuit <NUM>). Further, the antenna unit <NUM> may be implemented by the antenna <NUM>. Moreover, the storage unit <NUM> may be implemented by the memory <NUM>.

<FIG> is a block diagram illustrating an example of a schematic configuration of a car navigation device <NUM> to which the technology of the present disclosure may be applied. The car navigation device <NUM> includes a processor <NUM>, a memory <NUM>, a global positioning system (GPS) module <NUM>, a sensor <NUM>, a data interface <NUM>, a content player <NUM>, a storage medium interface <NUM>, an input device <NUM>, a display device <NUM>, a speaker <NUM>, a wireless communication interface <NUM>, one or more antenna switches <NUM>, one or more antennas <NUM>, and a battery <NUM>.

The processor <NUM> may be, for example, a CPU or a SoC, and controls a navigation function and another function of the car navigation device <NUM>. The memory <NUM> includes RAM and ROM, and stores a program that is executed by the processor <NUM>, and data.

The GPS module <NUM> uses GPS signals received from a GPS satellite to measure a position (such as latitude, longitude, and altitude) of the car navigation device <NUM>. The sensor <NUM> may include a group of sensors such as a gyro sensor, a geomagnetic sensor, and a barometric sensor. The data interface <NUM> is connected to, for example, an in-vehicle network <NUM> via a terminal that is not shown, and acquires data generated by the vehicle, such as vehicle speed data.

The content player <NUM> reproduces content stored in a storage medium (such as a CD and a DVD) that is inserted into the storage medium interface <NUM>. The input device <NUM> includes, for example, a touch sensor configured to detect touch onto a screen of the display device <NUM>, a button, or a switch, and receives an operation or an information input from a user. The display device <NUM> includes a screen such as a LCD or an OLED display, and displays an image of the navigation function or content that is reproduced. The speaker <NUM> outputs sounds of the navigation function or the content that is reproduced.

The wireless communication interface <NUM> supports any cellular communication scheme such as LET and LTE-Advanced, and performs wireless communication. The wireless communication interface <NUM> may typically include, for example, a BB processor <NUM> and an RF circuit <NUM>. The BB processor <NUM> may perform, for example, encoding/decoding, modulating/demodulating, and multiplexing/demultiplexing, and performs various types of signal processing for wireless communication. Meanwhile, the RF circuit <NUM> may include, for example, a mixer, a filter, and an amplifier, and transmits and receives radio signals via the antenna <NUM>. The wireless communication interface <NUM> may be a one chip module having the BB processor <NUM> and the RF circuit <NUM> integrated thereon. The wireless communication interface <NUM> may include the multiple BB processors <NUM> and the multiple RF circuits <NUM>, as illustrated in <FIG>. Although <FIG> illustrates the example in which the wireless communication interface <NUM> includes the multiple BB processors <NUM> and the multiple RF circuits <NUM>, the wireless communication interface <NUM> may also include a single BB processor <NUM> or a single RF circuit <NUM>.

Furthermore, in addition to a cellular communication scheme, the wireless communication interface <NUM> may support another type of wireless communication scheme such as a short-distance wireless communication scheme, a near field communication scheme, and a wireless LAN scheme. In that case, the wireless communication interface <NUM> may include the BB processor <NUM> and the RF circuit <NUM> for each wireless communication scheme.

Each of the antennas <NUM> includes a single or multiple antenna elements (such as multiple antenna elements included in an MIMO antenna), and is used for the wireless communication interface <NUM> to transmit and receive radio signals. The car navigation device <NUM> may include the multiple antennas <NUM>, as illustrated in <FIG>. Although <FIG> illustrates the example in which the car navigation device <NUM> includes the multiple antennas <NUM>, the car navigation device <NUM> may also include a single antenna <NUM>.

Furthermore, the car navigation device <NUM> may include the antenna <NUM> for each wireless communication scheme. In that case, the antenna switches <NUM> may be omitted from the configuration of the car navigation device <NUM>.

The battery <NUM> supplies power to blocks of the car navigation device <NUM> illustrated in <FIG> via feeder lines that are partially shown as dashed lines in the figure. The battery <NUM> accumulates power supplied form the vehicle.

In the car navigation device <NUM> shown in <FIG>, one or more constituent elements (the acquisition unit <NUM> and/or the reception processing unit <NUM>) included in the processing unit <NUM> described with reference to <FIG> may be implemented by the wireless communication interface <NUM>. Alternatively, at least some of these constituent elements may be implemented by the processor <NUM>. As an example, a module which includes a part (for example, the BB processor <NUM>) or all of the wireless communication interface <NUM> and/or the processor <NUM> may be mounted in the car navigation device <NUM>, and the one or more constituent elements may be implemented by the module. In this case, the module may store a program for causing the processor to function as the one or more constituent elements (i.e., a program for causing the processor to execute operations of the one or more constituent elements) and may execute the program. As another example, the program for causing the processor to function as the above-described one or more constituent elements may be installed in the car navigation device <NUM>, and the wireless communication interface <NUM> (for example, the BB processor <NUM>) and/or the processor <NUM> may execute the program. As described above, the car navigation device <NUM> or the module may be provided as a device which includes the above-described one or more constituent elements, and the program for causing the processor to function as the above-described one or more constituent elements may be provided. In addition, a readable recording medium in which the program is recorded may be provided.

In addition, in the car navigation device <NUM> shown in <FIG>, the wireless communication unit <NUM> described with reference to <FIG>, for example, may be implemented by the wireless communication interface <NUM> (for example, the RF circuit <NUM>). Further, the antenna unit <NUM> may be implemented by the antenna <NUM>. Moreover, the storage unit <NUM> may be implemented by the memory <NUM>.

The technology of the present disclosure may also be realized as an in-vehicle system (or a vehicle) <NUM> including one or more blocks of the car navigation device <NUM>, the in-vehicle network <NUM>, and a vehicle module <NUM>. In other words, the in-vehicle system (or a vehicle) <NUM> may be provided as a device which includes the acquisition unit <NUM> and/or the reception processing unit <NUM>. The vehicle module <NUM> generates vehicle data such as vehicle speed, engine speed, and trouble information, and outputs the generated data to the in-vehicle network <NUM>.

According to the present disclosure, a device including a processing unit configured to perform sensing using one of first sensing of sensing resources for a predetermined period and selecting communication resources on a basis of a result of the sensing and second sensing of selecting communication resources on a basis of a result of decoding control information transmitted by another user with reference to a mapping table at the time of the first sensing and the second sensing is provided.

Further, according to the present disclosure, a method including performing sensing using one of first sensing of sensing resources for a predetermined period and selecting communication resources on a basis of a result of the sensing and second sensing of selecting communication resources on a basis of a result of decoding control information transmitted by another user with reference to a mapping table at the time of the first sensing and the second sensing is provided.

Further, according to the present disclosure, a first centralized sensing method and a second centralized sensing method are provided to improve efficiency of sensing.

Further, according to the present disclosure, the first centralized sensing method includes deciding, by an eNB or an RSU, one or more representatives performing sensing, assigning resources to one or more representatives performing the sensing, and liberating one or more representatives performing the sensing.

Further, according to the present disclosure, a method in which the eNB or the RSU decides one or more representatives performing sensing and a method in which the eNB or the RSU liberates one or more representatives performing sensing are included. Further, the second centralized sensing method including giving a notification to the UE, deciding one or more representatives performing sensing, using the information notified by the UE, and liberating one or more representatives performing the sensing, is provided.

Further, according to the present disclosure, since it is possible to implement transmission with less collision while maintaining fairness among users, two energy sensing + LBT sensing methods are provided.

Further, according to the present disclosure, in V2X communication, a first sensing method of energy sensing + LBT with Backoff according to the severity of latency requirements.

Further, according to the present disclosure, in V2X communication, a second sensing method of Energy sensing + LBT without Backoff according to the severity latency requirements is provided.

Further, according to the present disclosure, a method including deciding switching between the LBT with Backoff and the LBT without Backoff and notification of an LBT type is provided.

Further, according to the present disclosure, since a case in which the operation is performed while performing co-existence with the DSRC system (<NUM>. 11p communication), a two-step sensing method of detecting the DSRC system and avoiding packet collision with other users even within LTE V2X communication is provided.

Further, according to the present disclosure, in energy sensing + LBT, in the case of TDM, the SA pool and the data pool are divided in the time axis, and if the transmission authority for the SA resources and the resources of the data area are unable to be secured, transmission is unable to be performed, and thus three enhanced energy sensing + LBT sensing methods are provided.

Further, according to the present disclosure, in a case in which the transmission resources of the SA can be secured, a first Enhanced energy sensing + LBT sensing method of selecting the SA resources and the data data and transmitting a packet is provided.

Further, according to the present disclosure, in a case in which the transmission resources of data can be secured, a second enhanced energy sensing + LBT sensing method of selecting the SA resources and the data data and transmitting a packet is provided.

Further, according to the present disclosure, in a case in which both the transmission resources of the SA and the transmission resources of the data can be secured, a third enhanced energy sensing + LBT sensing method of selecting the SA resources and the data data and transmitting a packet is provided.

A person skilled in the art may find various alterations and modifications within the scope of the appended claims.

Claim 1:
A device (<NUM>) comprising
a processing unit (<NUM>) configured to perform sensing in a plurality of sensing modes, the plurality of sensing modes comprising:
a first sensing mode comprising sensing of resources for a predetermined period and selecting communication resources on a basis of a result of the sensing, and
a second sensing mode comprising selecting communication resources on a basis of a result of decoding scheduling information transmitted by another user,
wherein the sensing is performed with reference to a mapping table at the time of the sensing, and the mapping table is a table in which one of the plurality of sensing modes to be used and a sensing parameter to be used are specified depending on a situation.