KR101415668B1 - Device for vehicle communication and method thereof - Google Patents

Abstract

The present invention relates to a vehicle communication device and a communication method thereof, and more particularly, to an adaptive beam-based beam-division multiple access scheme in a smart antenna-based communication system in which a plurality of infrastructures exist, There is provided a method for beam and beam power allocation that can increase the capacity of a communication system by mitigating communication interference within a cell where the beam affects other vehicles and communication interference between cells by beams formed from adjacent infrastructures toward other vehicles The present invention relates to a vehicle communication device using a smart antenna and a communication method therefor.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a vehicle communication device,

The present invention relates to a vehicle communication device and a communication method thereof. More particularly, the present invention relates to an adaptive beam-based beam-division multiple access (OFDM) communication system in which a plurality of infrastructures exist in a smart antenna-based communication system, and a beam forming from one infrastructure to a vehicle affects other vehicles An apparatus for communicating a vehicle using a smart antenna, which provides a method for allocating a beam and a beam power capable of increasing the capacity of a communication system by mitigating communication interference between cells due to communication interference and a beam formed from an adjacent infrastructure to another vehicle, And a communication method.

With the rapid development of the automobile industry, the development of TELEMATICS technology, which is a vehicle wireless Internet service that combines automobile and wireless communication, has increased the demand for wireless vehicle communication.

The vehicle communication system consists of the infrastructure of the vehicle and the surrounding roads to provide real-time traffic information and vehicle communication applications for the safety of the vehicle and the driver and the improvement of the traffic flow. Here, the vehicle communication application may include a road safety application that provides information about a vehicle in an emergency, a traffic management application that provides information about the traffic flow, and a user infotainment application that provides entertainment information through an Internet connection And the like.

Generally, a vehicle communication system includes a V2I (Vehicle to Infrastructure) communication system provided through wireless communication between an infrastructure and a vehicle, and a V2V (Vehicle to Vehicle) communication system provided through wireless communication between vehicles.

In the case of the V2I communication system, it is difficult to allocate resources in consideration of the location and the moving speed of the vehicle by applying a method of providing information through radio communication using an omnidirectional antenna in the past, so that communication capacity and QoS are lowered And there is a problem that unnecessary resources are wasted in a space without a vehicle.

In order to solve this problem, an adaptive beam-based beam division multiple access (OFDM) scheme, which maximizes a capacity of a communication system by preventing an unnecessary waste of communication resources by forming an adaptive beam in consideration of a vehicle position and a moving speed, .

The beam division multiple access scheme is a space reuse scheme for forming an adaptive beam in a plurality of vehicles simultaneously in the same frequency band, and is advantageous in that a large amount of data can be transmitted. However, as the spread of smart devices has increased in recent years, demand for user information applications has increased, data traffic and network instability have occurred, and data is transmitted using the same frequency, There is a problem that a communication interference phenomenon occurs in a cell affecting another vehicle located at the adjacent position. In addition, when a beam is formed from a plurality of infrastructures, a communication formed between a beam formed from one infrastructure and a beam formed from another infrastructure may occur.

FIG. 1 is a view for explaining a problem of a conventional vehicular communication apparatus. FIG. 1 (a) is a view for explaining an interference phenomenon in a cell, and FIG. 1 (b) FIG.

1 (a), the first and second infrastructures 10 and 20 are located adjacent to each other and a plurality of vehicles 31, 32, 33 and 34 on the road are connected to the V2I communication system using the smart antenna, And receive data. For example, the first infrastructure 10 simultaneously transmits adaptive beams b1 and b2 toward vehicles 31 and 32 at the same frequency to transmit data. When the speed of the vehicle 31 increases while the vehicle 31 and the vehicle 32 travel in the same direction in the same lane and is located adjacent to the vehicle 32, Lt; RTI ID = 0.0 > cell. ≪ / RTI >

The second infrastructure 20 simultaneously transmits adaptive beams b11 and b12 toward the vehicles 33 and 34 at the same frequency as the first infrastructure 10 to transmit data. If the vehicle 33 and the vehicle 34 are located at the same angle from the second infrastructure 200 while the vehicle 33 and the vehicle 34 travel in different lanes, 34 may cause communication interference in the cell.

1 (b), the vehicle 31, 32, 33, 34 moves so that the first infra-structure 10 forms the adaptive beams b1, b2 toward the vehicle 31, 33, The second infrastructure 20 forms the adaptive beams b11 and b12 toward the vehicles 32 and 34 to transmit and receive data. When the vehicles 31 and 32 are traveling in the same direction in different lanes while traveling in the same direction, the adaptive beam b1 formed by the first infrastructure 10 and the adaptive beam b1 formed by the second infrastructure 20 Communication interference between cells may occur due to the beam b11. Even when the vehicles 33 and 34 travel in the direction opposite to the vehicles 31 and 32 and travel in the same direction while traveling in the same direction in the different lanes, Communication interference between cells may occur due to the beam b2 and the adaptive beam b12 formed by the second infrastructure 20.

(Patent Literature)

Korean Published Patent No. 2011-0135030 (Published on July 07, 2011)

As described above, in the related art, when a plurality of infrastructures 10 and 20 are located adjacent to the road side, there is a problem that interference in a cell and communication interference between cells occur, thereby decreasing a capacity of a communication system.

Therefore, the present invention uses an adaptive beam-based beam-division multiple access scheme in a smart antenna-based communication system in which a plurality of infrastructures exist, and uses a beam forming a beam toward a vehicle from one infrastructure to a cell And to increase the capacity of a communication system by mitigating communication interference between cells due to a beam formed from an adjacent infrastructure toward another vehicle, and a communication method therefor.

The present invention relates to a vehicle communication device including a plurality of antennas having a single cell as a communication coverage, comprising: a communication unit for transmitting and receiving information to and from each of a plurality of vehicles located in the cell; A beam allocator for selecting a vehicle having the least communication interference between cells by the cell adjacent to the cell and allocating an adaptive beam in a direction of the selected vehicle and a communication controller for controlling communication interference in the cell and communication interference And a beam power allocating unit for controlling the size of the beam power according to the size of the beam power.

The beam allocator is characterized in that the vehicle having the largest signal-to-noise interference ratio of the communication link to each vehicle among the plurality of vehicles is selected as the communication interference within the cell and the vehicle with the least communication interference between the cells . Here, the signal-to-

Equation

은 열 잡음 파워, b는 상기 적응성 빔, k는 상기 안테나에 접속하는 차량,

는 타임 슬롯 n에서 상기 적응성 빔 b에 대한 전송 파워, θ(b,k)는 상기 적응성 빔 b의 방향과 상기 차량 k의 방향 사이의 각도,

는 상기 타임 슬롯 n에서 상기 접속된 안테나와 차량 k 사이의 채널 이득,

는 상기 셀 내의 통신 간섭을 나타내고,

는 셀 간의 통신 간섭)로 정의되는 것을 특징으로 한다.(here,

B is the adaptive beam, k is the vehicle connecting to the antenna,

Is the transmission power for the adaptive beam b in timeslot n, [theta] (b, k) is the angle between the direction of the adaptive beam b and the direction of the vehicle k,

Is the channel gain between the connected antenna and the vehicle k in the time slot n,

Indicates communication interference in the cell,

Is a communication interference between cells).

는 상기 차량 k가 상기 접속된 안테나를 통해 다른 차량에 형성된 적응성 빔 a에 의해 간섭 채널이 형성되는 경우, 상기 적응성 빔 a의 전송 파워와 상기 차량 k에서의 간섭 채널 이득의 곱에 대응하는 크기에 대응하는 것을 특징으로 한다. 또한, 상기

는 상기 차량 k가 상기 접속한 안테나와 인접한 안테나에 접속한 다른 차량에 형성된 적응성 빔 a에 의해 간섭 채널이 형성되는 경우, 상기 적응성 빔 a의 전송 파워와 차량 k에서의 간섭 채널 이득의 곱에 대응하는 크기에 대응하는 것을 특징으로 한다.Then,

Corresponds to the product of the transmission power of the adaptive beam a and the interference channel gain in the vehicle k when the vehicle k is formed by the adaptive beam a formed in another vehicle via the connected antenna . In addition,

Corresponds to the product of the transmission power of the adaptive beam a and the interference channel gain in the vehicle k when the interference channel is formed by the adaptive beam a formed on another vehicle connected to the antenna adjacent to the antenna to which the vehicle k is connected The size of which corresponds to the size of the image.

The beam allocating unit allocates one or more vehicles for each adaptive beam. The beam power allocating unit may increase the beam power when the communication interference in the cell and the communication interference between the cells for the selected vehicle decrease. The beam power allocator increases the beam power when the signal-to-noise interference ratio of the communication link to the selected vehicle increases.

 The beam power allocating unit allocates the transmission power of the adaptive beam to be larger than 0 and the total transmission power of the adaptive beam to be smaller than the maximum beam power.

The present invention also provides a communication method for a vehicle communication apparatus having a plurality of antennas having a single cell as a communication coverage, the communication method comprising the steps of: detecting communication interference in the cell among a plurality of vehicles in the cell, Selecting one vehicle with the least communication interference and allocating the adaptive beam in the direction of the selected vehicle and controlling the size of the beam power according to the communication interference within the cell and the communication interference between the cells for the selected vehicle .

The step of allocating the adaptive beam may include selecting a vehicle having the largest signal-to-noise interference ratio of the communication link for each vehicle among the plurality of vehicles as a communication interference in the cell and a vehicle having the least communication interference among the cells The method comprising the steps of:

The step of controlling the size of the beam power may include an initializing step of dividing the maximum transmittable beam power by the total number of the adaptive beams and equally allocating the beam power; And increasing the beam power when the communication interference in the cell and the communication interference between the cells for the selected vehicle decrease. In addition, the step of increasing the beam power may increase the beam power when the signal-to-noise interference ratio of the communication link to the selected vehicle increases.

The present invention relates to a vehicle communication apparatus and a communication method therefor, in which a beam-division multiple access scheme based on an adaptive beam is used in a smart antenna-based communication system in which a plurality of infrastructures exist and a beam formed from one infrastructure toward a vehicle An effect is achieved in which communication interference in a cell affecting another vehicle and communication interference between cells due to a beam formed from an adjacent infrastructure toward another vehicle are reduced to increase the capacity of the communication system.

1 is a view for explaining a problem of a conventional vehicular communication device.
2 is a conceptual block diagram showing a vehicle communication device according to an embodiment of the present invention;
3 is a diagram for explaining a communication method of a vehicle communication device according to an embodiment of the present invention.

The following detailed description of the invention refers to the accompanying drawings, which illustrate, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly explained. In the drawings, like reference numerals refer to the same or similar functions throughout the several views.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily carry out the present invention.

2 is a conceptual block diagram showing a vehicle communication device according to an embodiment of the present invention.

2, the vehicle communication device of the present invention includes a first and a second infrastructure 100, It is assumed that the first and second infrastructure 100 and 200 according to the embodiment of the present invention share the frequency band and simultaneously allocate the adaptive beam to the vehicles at different positions to transmit and receive data. The communication coverage area of each of the first and second infrastructure 100 and 200 is defined as a cell and the communication coverage area of the first infrastructure 100 is described as a first cell. Area will be described as a second cell. The detailed configuration of the second infrastructure 200 is the same as the detailed configuration of the first infrastructure 100, and the description thereof will be omitted for the sake of convenience of explanation.

The first infrastructure 100 includes a communication unit 101, an information collecting unit 103, a beam control unit 105, and an information providing unit 107. Here, the communication unit 101 transmits and receives information to and from each of a plurality of vehicles located in the cell, including an antenna. In the embodiment of the present invention, it is assumed that each of a plurality of vehicles includes a GPS (Global Positioning System). Accordingly, the communication unit 101 receives the position, direction, moving speed, channel state information, and the like of each vehicle through GPS. The communication unit 101 transmits road safety, traffic management, user information application, and the like received from the information providing unit 107 to a selected one of the plurality of vehicles.

The information collecting unit 103 periodically connects to each of a plurality of vehicles through the communication unit 101 to collect the position, direction, moving speed, and communication channel state information of the vehicle. In addition, the information collecting unit 103 according to the embodiment of the present invention shares the information collected by the second infrastructure 200.

The beam controller 105 allocates an adaptive beam to a selected one of a plurality of vehicles connected to the first infrastructure 100, and controls the power of the allocated adaptive beam. To this end, the beam control unit 105 includes a beam allocation unit 1051 and a beam power allocation unit 1053. [

Here, the beam allocating unit 1051 selects a vehicle having the smallest communication interference in the first cell and the communication interference between the cells in the second cell among the plurality of vehicles connected to the first infrastructure 100, . Specifically, the beam allocating unit 1051 allocates the vehicle having the largest signal to interference plus noise ratio (SINR) of the communication channel formed with each of the plurality of vehicles connected to the first infrastructure 100 It is determined that the communication interference in the first cell and the communication interference between the cells due to the second cell are the smallest, and is selected. This will be described in detail below.

When the adaptive beam is allocated by the beam allocating unit 1051, the beam power allocating unit 1053 allocates the beam power according to the communication interference in the first cell and the communication interference between the cells due to the second cell . The beam power allocating unit 1053 according to the embodiment of the present invention can reduce the communication interference in the first cell and the communication interference between the cells due to the second cell becomes smaller or the beam power allocation in the communication channel of the vehicle to which the adaptive beam is allocated It is desirable to increase the beam power when the signal-to-noise interference ratio increases.

The information providing unit 107 provides road safety, traffic management, user information application, and the like to the vehicle selected by the beam controller 105.

Hereinafter, a communication method of the vehicle communication device according to the embodiment of the present invention will be described with reference to FIG.

3 is a diagram for explaining a communication method of a vehicle communication device according to an embodiment of the present invention. In Fig. 3, arrows indicated by solid lines represent signal channels, and arrows indicated by dotted lines represent interference channels.

First, the set of infrastructures is I = {1, ... , I}. In the following description, the first infrastructure 100 is expressed as an infrastructure i, and the second infrastructure 200 is represented as an infrastructure j for convenience in explanation. One frame contains N downlink timeslots, and the set is N = {1, ... , N}, respectively. Then, the set of vehicles located in the communication service area is expressed as K = {1, ... , K}, and the set of vehicles connecting to the infrastructure i among the vehicle sets is defined as Ki = {1, ..., K). , Ki}. Then, the set of adaptive beams that infrastructure i forms simultaneously toward the vehicles is Bi = {1, ... , B}. The maximum number of adaptive beams that can be formed simultaneously by the infrastructure i is assumed to be B.

Then, in the time slot n, when the adaptive beam b is allocated from the infrastructure i to the vehicle k, the signal-to-noise interference ratio? In the communication link of the vehicle k is expressed by the following equation (1).

은 열 잡음 파워를 나타내고,

는 타임 슬롯 n에서 인프라 i의 적응성 빔 b에 대한 전송 파워를 나타낸다. 그리고,

는 적응성 빔 b의 방향과 차량 k의 방향 사이의 각도가 θ(b,k)일 때, 타임 슬롯 n에서 인프라 i와 차량 k 사이의 채널 이득을 나타낸다. here,

Represents the thermal noise power,

Represents the transmission power for adaptive beam b of infrastructure i in time slot n. And,

Represents the channel gain between infrastructure i and vehicle k in timeslot n when the angle between the direction of adaptive beam b and the direction of vehicle k is [theta] (b, k).

는 제1 셀 내부에서의 통신 간섭을 나타내고,

는 제2 셀에 의한 셀 간의 통신 간섭을 나타낸다. 즉, 차량 k의 신호 대 잡음 간섭비(γ)는 제1 셀 내부에서의 통신 간섭 및 제2 셀에 의한 셀 간의 통신 간섭이 작아질수록 그 값이 커진다. Also,

Indicates communication interference in the first cell,

Represents the communication interference between cells by the second cell. That is, the signal-to-noise interference ratio? Of the vehicle k increases as the communication interference in the first cell and the communication interference between cells due to the second cell become smaller.

는 아래의 [수학식 2]로 표현된다. 즉, 차량 k가 인프라 i를 통해 다른 차량에 형성된 적응성 빔 a에 의해 간섭 채널이 형성되는 경우 차량 k에 대한 셀 내의 통신 간섭은 적응성 빔 a의 전송 파워와 차량 k에서의 간섭 채널 이득의 곱에 대응하는 크기로 발생할 수 있다. here,

Is expressed by the following equation (2). That is, when the interference channel is formed by the adaptive beam a formed on another vehicle via the infrastructure i, the communication interference in the cell for the vehicle k is multiplied by the transmission power of the adaptive beam a and the interference channel gain in the vehicle k Can occur in corresponding sizes.

은 아래의 [수학식 3]으로 표현된다. 즉, 차량 k가 인프라 j를 통해 다른 차량에 형성된 적응성 빔 a에 의해 간섭 채널이 형성되는 경우 차량 k에 대한 셀 간의 통신 간섭은 적응성 빔 a의 전송 파워와 차량 k에서의 간섭 채널 이득의 곱에 대응하는 크기로 발생할 수 있다.And,

Is expressed by the following equation (3). That is, when the interference channel is formed by the adaptive beam a formed in another vehicle via the infrastructure j, the communication interference between the cells for the vehicle k is a product of the transmission power of the adaptive beam a and the interference channel gain in the vehicle k Can occur in corresponding sizes.

Meanwhile, the beam controller 105 of the present invention preferably controls adaptive beam allocation and beam power to maximize the communication system capacity of the entire infrastructure i, j. To this end, the beam control unit 105 of the present invention controls the beamforming system such that the constraint conditions such as the following equations (1.1) and (1.2) for the adaptive beam allocation and the constraint conditions such as the following equations (1.3) And controls adaptive beam allocation and beam power.

[Formula 1.1]

[Formula 1.2]

[Formula 1.3]

[Formula 1.4]

는 인프라 i가 차량 k에 적응적 빔을 할당했는지 여부를 나타낸다. 예컨대, 타임 슬롯 n에서 인프라 i가 차량 k에 적응적 빔을 할당한 경우

는 1을 만족하고, 아니면 0을 만족한다. here,

Indicates whether infrastructure i has assigned an adaptive beam to vehicle k. For example, if infrastructure i has assigned an adaptive beam to vehicle k in timeslot n

Satisfies 1, or 0 otherwise.

That is, equations (1.1) and (1.2) indicate that one adaptive beam b should be allocated to one or less vehicles. Equation (1.3) indicates that the transmission power of the adaptive beam b must be greater than or equal to zero, and Equation (1.4) indicates that the total transmission power of the adaptive beam b should be less than the total power of the infrastructure i.

Under this condition, the beam allocating unit 1051 allocates the smallest communication interference between the cells in the first cell and the second cell due to the smallest signal-to-noise interference ratio among the plurality of vehicles connected to the infrastructure i, Select vehicle k *. This can be expressed by the following equation (4).

는 1을 만족하고, 나머지 차량 k에 대한

는 0을 만족한다. Then, the beam allocation unit 1051 allocates the adaptive beam b to the selected vehicle k *. Thus, for the selected vehicle k *

1 < / RTI > and for the remaining vehicle k

0 ".

Thus, when the adaptive beam b is allocated to the vehicle k *, the beam power allocation unit 1053 controls the transmission power p of the adaptive beam b. The transmission power p for the adaptive beam b of the infrastructure i according to the embodiment of the present invention can be expressed as Equation (5) below.

을 의미하고,

및

는 아래의 [수학식 6] 및 [수학식 7]과 같이 표현될 수 있다.

는 인프라 i의 적응적 빔 b이 다른 통신 링크를 발생시키는 내부 셀에서의 통신 간섭의 양에 비례하는 누적 값을 나타내고,

는 인프라 i의 적응적 빔 b이 다른 인프라 j의 셀에 대한 셀 간의 통신 간섭의 양에 비례하는 누적 값을 나타낸다. 그리고, 는 인프라 i를 향해 단위 시간 당 도착하는 차량의 비율을 의미하며, 0이상의 값을 가진다.Here,

Lt; / RTI >

And

Can be expressed by the following equations (6) and (7).

Represents an accumulated value proportional to the amount of communication interference in the inner cell generating the other communication link,

Represents an accumulated value proportional to the amount of communication interference between cells for a cell of another infrastructure j, the adaptive beam b of infrastructure i. The term " vehicle " means the ratio of vehicles arriving per unit time toward the infrastructure i, and has a value of zero or more.

의 값이 감소)하고, 제2 셀에 의한 셀 간의 통신 간섭이 감소(즉,

값이 감소)하는 경우이거나, 또는 인프라 i의 차량 k에 대한 통신 링크의 신호 대 잡음 간섭비(γ)가 증가하면 빔 파워를 증가시키는 것이 바람직하다.That is, the beam power allocation unit 1053 according to the embodiment of the present invention reduces the communication interference in the first cell with respect to the adaptive beam b of the infrastructure i (i.e.,

And the communication interference between cells by the second cell is reduced (that is,

It is desirable to increase the beam power if the signal-to-noise interference ratio gamma of the communication link to vehicle k of infrastructure i increases.

Hereinafter, the procedure of beam and beam power allocation according to the embodiment of the present invention will be described in each step on the basis of the above-described equations.

Initialization phase

First, the beam power p is initialized. Then, beam allocation is performed to the vehicle having the highest signal-to-noise selection ratio? Among a plurality of vehicles according to Equation (4).

Next, t is calculated according to Equation (6) and Equation (7) based on the initial beam power and beam allocation.

Beam power and beam allocation update  step

First, the beam power allocation p is updated according to Equation (5).

And then updates the allocation of the adaptive beam b based on the updated beam power p. Then, when beam power and beam allocation are updated, t is updated. In this way, the initialization and updating process is repeated.

However, since the above process requires a complicated mathematical calculation, it is preferable to allocate the beam and beam power by the following heuristic method.

Initialization phase

First, the allocation of the beam power p is initialized, and the beam power p is equally allocated by dividing the maximum transmittable power Pmax by the total number of the adaptive beams.

Beam allocation step

Based on the initialized beam power p, beam allocation is performed to the vehicle having the highest signal-to-noise selection ratio? In the plurality of vehicles according to Equation (4).

Beam power allocation step

The beam power is allocated according to Equation (3).

As described above, the vehicle communication device and the communication method thereof according to the embodiment of the present invention use an adaptive beam-based beam division multiple access scheme in a smart antenna-based communication system, The communication interference in the first cell and the communication interference between the cells in the second cell are selected and the data is transmitted. It is also possible to adjust the size of the beam power according to the magnitude of the communication interference in the cell where the beam formed towards the selected vehicle affects the other vehicle and the size of the communication interference between cells due to the beam formed from other infrastructure or the magnitude of the signal- Is applied. Thus, the beam formed toward one vehicle can mitigate interference within the cell that affects other vehicles and communication interference between cells due to beams formed from other infrastructures, thereby maximizing the capacity of the communication system.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Therefore, the spirit of the present invention should not be construed as being limited to the above-described embodiments, and all of the equivalents or equivalents of the claims, as well as the following claims, I will say.

100: First Infrastructure
200: Second Infrastructure
101:
103: Information collecting section
105: beam controller
107: Information provision

Claims (13)

1. A vehicle communication device comprising a plurality of antennas having one cell as a communication coverage,
A communication unit for transmitting and receiving information to and from each of a plurality of vehicles located in the cell;
A beam allocator for selecting a vehicle in which communication interference in the cell among the plurality of vehicles and communication interference between cells by cells adjacent to the cell are the least and allocating the adaptive beam in the selected vehicle direction; And
And a beam power allocator for controlling the size of the beam power according to the communication interference in the cell and the communication interference between the cells for the selected vehicle,
Wherein the beam allocating unit selects a vehicle having the largest signal-to-noise interference ratio of the communication link for each vehicle among the plurality of vehicles as a communication interference in the cell and a vehicle having the least communication interference among the cells,
The signal-to-
Equation

(here,

B is the adaptive beam, k is the vehicle connecting to the antenna,

Is the transmission power for the adaptive beam b in timeslot n, [theta] (b, k) is the angle between the direction of the adaptive beam b and the direction of the vehicle k,

Is the channel gain between the connected antenna and the vehicle k in the time slot n,

Indicates communication interference in the cell,

Lt; RTI ID = 0.0 > inter-cell &
Is defined as < RTI ID = 0.0 > a < / RTI >
delete delete The method according to claim 1,
remind

Corresponds to the product of the transmission power of the adaptive beam a and the interference channel gain in the vehicle k when the vehicle k is formed by the adaptive beam a formed in another vehicle via the connected antenna Wherein the vehicle communication device is a vehicle communication device.
The method according to claim 1,
remind

Corresponds to the product of the transmission power of the adaptive beam a and the interference channel gain in the vehicle k when the interference channel is formed by the adaptive beam a formed on another vehicle connected to the antenna adjacent to the antenna to which the vehicle k is connected The size of which corresponds to the size of the vehicle.
The method according to claim 1,
Wherein the beam allocating unit allocates one or more vehicles for each adaptive beam.
The method according to claim 1,
Wherein the beam power allocating unit increases the beam power when the communication interference in the cell and the communication interference between the cells for the selected vehicle are reduced. The method according to claim 1,
Wherein the beam power allocator increases the beam power when the signal-to-noise interference ratio of the communication link to the selected vehicle increases.
The method according to claim 1,
Wherein the beam power allocating unit allocates the transmission power of the adaptive beam to be larger than 0 and the total transmission power of the adaptive beam to be smaller than the maximum beam power.
1. A communication method for a vehicle communication apparatus having a plurality of antennas each having one cell as a communication coverage,
Selecting one vehicle among the plurality of vehicles in the cell that has the least communication interference between the cells and cells that are adjacent to the cell and allocating an adaptive beam in the direction of the selected vehicle; And
Controlling the magnitude of the beam power according to a magnitude of communication interference in the cell and communication interference between the cells for the selected vehicle,
Wherein the step of allocating the adaptive beam comprises:
Selecting a vehicle having the largest signal-to-noise interference ratio of a communication link for each vehicle among the plurality of vehicles as a vehicle with the least communication interference among the cells and communication interference between the cells,
The signal-to-
Equation

(here,

B is the adaptive beam, k is the vehicle connecting to the antenna,

Is the transmission power for the adaptive beam b in timeslot n, [theta] (b, k) is the angle between the direction of the adaptive beam b and the direction of the vehicle k,

Is the channel gain between the connected antenna and the vehicle k in the time slot n,

Indicates communication interference in the cell,

Lt; RTI ID = 0.0 > inter-cell &
Of the vehicle communication device.
delete 11. The method of claim 10,
The step of controlling the magnitude of the beam power comprises:
Dividing the maximum transmittable beam power by the total number of the adaptive beams and allocating the beam power equally; And
And increasing the beam power when communication interference within the cell and communication interference between the cells for the selected vehicle is reduced.
13. The method of claim 12,
The step of increasing the beam power comprises:
And increases the beam power when the signal-to-noise interference ratio of the communication link to the selected vehicle increases.

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