KR101998221B1 - Resource Allocation Method for Multiple Device-to-Device Cluster Multicast Communications Underlay Cellular Networks and Apparatus thereof - Google Patents

Abstract

A resource allocation method and apparatus for multi-D2D cluster multicast communication are disclosed. A method for allocating resources for multiple D2D cluster multicast communication according to an embodiment of the present invention is a method for allocating at least one cellular terminal and at least one D2D cluster in a cell covered by one base station, A method for allocating resources to D2D clusters in a system in which a transmitting terminal and a plurality of receiving terminals are located, the method comprising the steps of: acquiring location information of a cellular terminal and a transmitting terminal located in a cell, Calculating an outage probability of a corresponding D2D cluster using the calculated transmission power, calculating a transmission power of a transmitting terminal by using a predetermined out-of-cell probability and an outage probability, The sum of throughputs of all D2D clusters is calculated using the calculated outage probability And allocating a channel to be maximized.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resource allocation method for multiple D2D cluster multicast communication,

The present invention relates to a resource allocation method and apparatus for multi-D2D (Multi-D2D) cluster multicast communication, and more particularly, to a method and apparatus for allocating resources for a multi- The present invention relates to a resource allocation method and apparatus for multiple D2D cluster multicast communication.

D2D (Device to Device) communication, which can directly transmit data between terminals without passing through network infrastructure such as base stations and repeaters, has been developed with the spread of smart phones and pad type mobile terminals and various service demands using mobile terminals Has been highlighted.

In a network capable of D2D communication, a terminal of a base station-based communication system and a D2D communication terminal share the same frequency resource and coexist in a conventional cellular system.

Therefore, interference between D2D terminals and cellular terminals may occur. In order to solve this problem, it is important to appropriately allocate resources such as transmission power and frequency within a range where interference intensity is allowed in a cellular network in D2D communication.

However, conventionally, the base station allocates resources (Channel Allocation using Full Information of Device Locations (CA-FIL)) by knowing location information of all the cellular terminals, D2D transmitting terminals, and D2D receiving terminals located in the cell covered by the base station, There is a problem that overhead is generated a lot. In case of CA-FIL, overhead is also increased when the number of D2D receiving terminals multicasting data by the D2D transmitting end increases.

Therefore, it is required to develop a technique that can reduce the overhead in allocating resources to multiple D2D clusters.

In this regard, Korean Patent Registration No. 10-1672632 entitled " Dynamic Cluster-Based Resource Allocation Method for D2D Communication "exists.

The present invention is directed to a resource allocation method for multiple D2D cluster multicast communication in which resources are allocated using a location of a cellular terminal in a cell covered by one base station and a transmitting terminal located in a multiple D2D cluster, And to provide such a device.

Another object of the present invention is to provide a resource allocation method and apparatus for multiple D2D cluster multicast communication in which frequency resources are allocated so as to maximize the effective throughput (ET) of a D2D cluster will be.

The technical problems of the present invention are not limited to the above-mentioned technical problems, and other technical problems which are not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a method for allocating resources for multiple D2D cluster multicast communication according to an exemplary embodiment of the present invention, including: providing at least one cell terminal and at least one D2D cluster in a cell covered by one base station A method for allocating resources to D2D clusters in a system in which a transmitting terminal and a plurality of receiving terminals are located in each D2D cluster, the method comprising the steps of: acquiring location information of a cellular terminal and a transmitting terminal located in a cell; , The base station calculates a transmission power of a transmitting terminal using the location information and a predetermined out-of-cellular probability, and the base station calculates an outage probability of the corresponding D2D cluster using the calculated transmission power And the base station uses the calculated outage probability And allocating a channel to each D2D cluster, wherein the outage probability of the D2D cluster is determined based on an average of the receiving terminal data rates calculated using the distance between the cellular terminal and the transmitting terminal and the transmission power of the transmitting terminal .

Preferably, calculating the transmission power of the transmitting terminal may include calculating a distance between the cellular terminal and the base station, a distance between the transmitting terminal and the base station using the position information of the cellular terminal and the transmitting terminal, The transmission power of the transmitting terminal can be calculated using the cellular outage probability and the transmission power of the cellular terminal.

Preferably, the calculating the outage probability of the D2D cluster includes calculating a distance between the cellular terminal and the transmitting terminal using the location information of the cellular terminal and the transmitting terminal, calculating the distance between the calculated distance and the calculated transmission Calculating an average of the reception terminal data rates using the power and calculating an outage probability of the D2D cluster based on the average of the calculated reception terminal data rates.

Advantageously, the step of allocating channels may allocate channels such that the sum of throughputs of all D2D clusters is maximized.

Advantageously, the step of allocating channels may allocate channels using a bipartite matching algorithm.

According to another aspect of the present invention, there is provided a resource allocation apparatus comprising: a location information acquiring unit acquiring location information of a cellular terminal and a transmitting terminal located in a cell; A transmission power allocation unit for calculating and allocating a transmission power of a transmitting terminal using an outage probability; an outage probability calculating unit for calculating an outage probability of the corresponding D2D cluster using the allocated transmission power, Wherein the outage probability of the D2D cluster is calculated by using a distance between the cellular terminal and the transmission terminal and a transmission power of the transmission terminal, Lt; RTI ID = 0.0 > data rates. ≪ / RTI >

Preferably, the transmission power allocation unit calculates the distance between the cellular terminal and the base station and the distance between the transmitting terminal and the base station using the location information of the cellular terminal and the transmitting terminal, and calculates the distance, the cellular outage probability, The transmission power of the transmitting terminal can be calculated using the transmission power of the terminal.

Preferably, the channel allocation unit calculates the distance between the cellular terminal and the transmission terminal using the location information of the cellular terminal and the transmission terminal, and calculates a distance between the cellular terminal and the transmission terminal using the calculated distance and the allocated transmission power, And calculate an outage probability of the D2D cluster based on the average of the calculated reception terminal data rates.

Advantageously, the channel allocator may allocate a channel using a bipartite matching algorithm.

According to the present invention, the overhead of the base station can be reduced by allocating resources using only the positions of the cellular terminal and the transmitting terminal. That is, even if the number of receiving terminals supported by the D2D cluster increases, the overhead of the base station is not affected.

In addition, by designing a resource allocation scheme for multiple D2DC multicast communication underlay cellular networks, it is possible to maximize the total effective throughput assuming that the cellular link is guaranteed a certain level of QoS.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood to those of ordinary skill in the art from the following description.

에 대한 CA-PIL의 ET 최대합을 나타낸 도면이다.
도 6은 활성 D2D 클러스터당 ET 최대합을 나타낸 도면이다.1 is a diagram for explaining a multicast communication system based on multiple D2D clusters according to an embodiment of the present invention.
2 is a flowchart illustrating a resource allocation method for multicast communication of multiple D2D clusters in a cellular network according to an exemplary embodiment of the present invention.
3 is a view for explaining a base station allocating resources to multiple D2D clusters according to an embodiment of the present invention.
FIG. 4 is a diagram showing maximum ET sums of CA-FIL and CA-PIL (analytic, actual) for the receiving terminal Nm.
Figure 5

0.0 > CA-PIL < / RTI >
6 is a graph showing the maximum ET sum per active D2D cluster.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

The terms first, second, A, B, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

The D2D communication described below is basically based on a mobile communication network. The technique described below also relates to a technique by which a base station manages resources in D2D communication. A typical D2D communication environment includes a D2D terminal (terminal pair) that performs D2D communication on one base station coverage and a general cellular terminal that performs general mobile communication. A typical cellular terminal is hereinafter referred to as a CU (Cellular User).

The resource allocation scheme for D2D communication, which will be described below, assumes that a D2D terminal and a CU are distributed in a cell according to a uniform distribution, and a CU has more network environments than a D2D terminal. Assuming a general mobile communication cell environment

Hereinafter, the SINR of the transmitting terminal and the transmission power of the transmitting terminal have been described. However, this may have the same meaning as the SINR and the transmitting power of the D2D cluster to which the transmitting terminal belongs.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram for explaining a multicast communication system based on multiple D2D clusters according to an embodiment of the present invention.

1, a multi-D2D cluster-based multicast communication system according to an embodiment of the present invention includes K cellular terminals 300 and M D2D clusters 200 in a cell covered by a base station 100 And each D2D cluster 200 includes one D2D transmitting terminal 210 and a plurality of D2D receiving terminals 220.

The base station 100 allocates resources to the respective D2D clusters 200 using the location information of the cellular terminal 200 and the D2D transmitting terminal 210 belonging to each D2D cluster 200. [ Here, the resource may include a power resource (Tx power) and a frequency resource (Channel).

The base station 100 may be, for example, a base transceiver station (BTS) in GSM or CDMA, a NodeB in WCDMA, or an advanced NodeB (eNB or e-NodeB) in LTE, But is not limited to the examples.

The D2D transmitting terminal (DTx) 210 multicasts data to the D2D receiving terminals 220 located in the cluster to which the D2D transmitting terminal (DTx) 210 belongs using the power and channel allocated from the base station 100. [

Hereinafter, for convenience of explanation, the cellular terminal 300 is referred to as a CU, the D2D cluster 200 as a cluster, the D2D transmitting terminal 210 as a transmitting terminal, and the D2D receiving terminal 220 as a receiving terminal. Since the number of the transmitting terminal 210 and the number of the clusters 200 are the same, it is assumed that m (m = 1, 2, .., M) and the radius of the cluster m is r _m . Further, when the position of the base station 100 is defined as the origin o in the two-dimensional space, and the cell is a circle having a radius r _c , the cell is represented by b (o, r _c ). If the location of the transmitting terminal 210 located in the cluster m is y ^D _m, then the cluster m can be represented as b (y ^D _m , r _m ). When the positions of the CU 300 and the transmitting terminal 210 are modeled by a BPU (uniform binomial point process), the K CUs 300 and the M transmitting terminals 210 are distributed in b (o, r _c ) . Also, modeling the location of the receiving terminal 220 in each cluster 200 in a uniform BPP, Nm reception device (DRx) 220 are uniformly distributed independent of b (y ^D _m, r _m) . Therefore, when the positions of the k-th CU and the m-th transmitting terminal are denoted by y ^C _k and y ^D _m , respectively, the positions of the CU and the transmitting terminal 210 have a probability density function (pdf) as shown in Equation 1 below .

the positions of the receiving devices 220 of the cluster m denoted by y ^m _n have a probability density function as shown in Equation 2 below.

In the multi-D2D cluster multicast communication system constructed as described above, D2DC communication is allowed by sharing a channel with only one CU during an uplink period of cellular communication. At this time, different D2D clusters use a unique channel.

2 is a flowchart illustrating a resource allocation method for multicast communication of multiple D2D clusters in a cellular network according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the base station acquires location information of a cellular terminal and a transmitting terminal belonging to each cluster (S210), calculates a distance between the transmitting terminal and the base station, and a distance between the cellular terminal and the base station (S220). At this time, the base station may calculate the distance between the cellular terminal and the transmitting terminal by using the location information of the cellular terminal and the location information of the transmitting terminal. The method of calculating the distance between the two devices uses a conventional method, and a description thereof will be omitted.

When step S220 is performed, the base station calculates and allocates the transmission power of the transmitting terminal using the distance between the transmitting terminal and the base station, and the distance between the cellular terminal and the base station (S230). At this time, the base station can calculate the transmission power of the transmitting terminal by using the distance between the transmitting terminal and the base station, the distance between the cellular terminal and the base station, and the probability of the cellular outage.

The cluster may multicast data in the underlay cellular network over channel k only if it does not violate the cellular outage probability. Therefore, the cellular outage probability should be calculated.

)을 산출할 수 있다. Therefore, the base station can calculate the outage probability of the link from the cellular terminal to the base station using Equation (3)

) Can be calculated.

는 기지국의 SINR,

는 임계치,

는 채널 k를 통한 셀룰러 단말의 송신 전력,

는 채널 k를 통한 송신 단말의 송신전력,

는 송신단말과 기지국간의 거리,

은 셀룰러 단말과 기지국간의 거리, α는 경로손실지수,

는 잡음분산을 의미할 수 있다.here,

Is the SINR of the base station,

Lt; / RTI >

The transmission power of the cellular terminal through the channel k,

Is the transmission power of the transmitting terminal through the channel k,

Is the distance between the transmitting terminal and the base station,

Is the distance between the cellular terminal and the base station,? Is the path loss index,

May mean noise variance.

)은 아래 기재된 수학식 4를 이용하여 산출할 수 있다. The base station's SINR (

) Can be calculated using Equation (4) described below.

는 채널 k를 통한 셀룰러 단말과 기지국간의 채널이득,

는 채널k를 통한 송신단말과 기지국간의 채널이득일 수 있다. here,

A channel gain between a cellular terminal and a base station through a channel k,

May be the channel gain between the transmitting terminal and the base station over channel k.

로 미리 설정될 수 있다. 기지국의 아웃티지 확률이 미리 설정되면, 송신단말의 송신전력(

)은 아래 수학식 5와 같이 제한된다.As described above, the base station can calculate the outline of the cluster using Equation (3), but the uplink probability of the uplink from the cellular terminal to the base station is

As shown in FIG. If the outage probability of the base station is set in advance, the transmission power of the transmitting terminal (

) Is limited as shown in Equation (5) below.

는

와 같다.According to Equation (5), the transmission power of the transmitting terminal

The

.

로 미리 설정되면, 수학식 3의

를

로 변경하고, 그 수학식으로부터 송신단말의 송신전력을 산출할 수 있다. Further, the uplink probability of the uplink from the cellular terminal to the base station is

Is set in advance in Equation (3)

To

And the transmission power of the transmitting terminal can be calculated from the equation.

That is, the base station can calculate the transmission power of the transmitting terminal using Equation (6) described below.

는 셀룰러 단말로부터 기지국까지의 링크의 아웃티지 확률로, 미리 설정된 값일 수 있다.

는 셀룰러 단말의 송신전력,

는 임계치,

는 셀룰러 단말과 기지국간의 거리,

는 송신단말과 기지국간의 거리, α는 경로손실지수일 수 있다. here,

May be a preset value with an outage probability of a link from the cellular terminal to the base station.

Is the transmission power of the cellular terminal,

Lt; / RTI >

The distance between the cellular terminal and the base station,

Is the distance between the transmitting terminal and the base station, and? Is the path loss index.

)을 이용하여 각 수신단말의 데이터율(data rate)을 산출하고(S240), 수신단말들의 데이터율 평균(average data rate)을 이용하여 각 클러스터의 아웃티지 확률을 각각 산출한다(S250).
한편, 본 발명의 경우 셀룰러 단말과 송신단말간의 거리는 클러스터의 반경보다 무한히 크고(

), 이로 인해 셀룰러 단말과 수신단말간의 거리와 셀룰러 단말과 송신단말간의 거리는 근사화(

)할 수 있다. 또한,

의 분포가 주어진 k를 가진 모든 수신단말(n)에 대해 동일하다는 가정하에서,

또한 고정 k에 대해 수신단말(n)에 대해 동일하게 분포되고, d_mn = r이므로, 단계 S240는 생략될 수 있다. 이 경우, 기지국은 후술할 수학식 12 및 13을 이용하여 이용하여 수신단말 데이터율(data rate)들의 평균을 산출하며, 산출된 평균 데이터율을 이용한 수학식 11을 이용하여 각 클러스터의 아웃티지 확률을 산출할 수 있다.When the step S230 is performed, the BS calculates the distance between the cellular terminal and the transmission terminal and the allocated transmission power (

The data rate of each receiving terminal is calculated at step S240 and the outage probability of each cluster is calculated using the average data rate of the receiving terminals at step S250.
Meanwhile, in the present invention, the distance between the cellular terminal and the transmitting terminal is infinitely greater than the radius of the cluster

), Which causes the distance between the cellular terminal and the receiving terminal and the distance between the cellular terminal and the transmitting terminal to approximate (

)can do. Also,

Is the same for all receiving terminals n having a given k,

Is also uniformly distributed with respect to the receiving terminal n for fixed k, and d _mn = r, so that step S240 can be omitted. In this case, the base station calculates the average of the data rates of the receiving terminal using Equations (12) and (13) to be described later, and calculates the outage probability of each cluster using Equation (11) using the calculated average data rate Can be calculated.

Hereinafter, a method of calculating the outage probability of each cluster by the base station will be described in detail.

)을 산출한다. The base station calculates the SINR of the transmitting terminal using Equation (7)

).

는 채널 k를 통한 셀룰러 단말과 수신단말간의 채널이득,

는 채널k를 통한 송신단말과 수신단말 사이의 채널이득,

는 채널 k를 통한 셀룰러 단말의 송신 전력,

는 채널 k를 통한 송신 단말의 송신전력,

는 송신단말과 수신단말간의 거리,

는 셀룰러 단말과 수신단말간의 거리, α는 경로손실지수,

는 잡음분산을 의미할 수 있다. here,

A channel gain between a cellular terminal and a receiving terminal over a channel k,

A channel gain between the transmitting terminal and the receiving terminal through the channel k,

The transmission power of the cellular terminal through the channel k,

Is the transmission power of the transmitting terminal through the channel k,

The distance between the transmitting terminal and the receiving terminal,

Is the distance between the cellular terminal and the receiving terminal,? Is the path loss index,

May mean noise variance.

When the SINR of the transmitting terminal is calculated, the base station can calculate the outline of the cluster using Equation (8) described below.

는 채널 k를 통한 클러스터 m의 아웃티지 확률(outage probability)이고,

는 목표 처리량으로 아래 기재된 수학식 9로 산출될 수 있다. here,

Is the outage probability of the cluster m over channel k,

Can be calculated by the following equation (9) as the target throughput.

는 개별 D2D 링크의 아웃티지 확률의 임계치일 수 있다. here,

May be a threshold of the outage probability of an individual D2D link.

As described above, the base station can calculate the outage probability of the cluster using the SINR from the transmitting terminal to the receiving terminal, but the criterion for finally determining the outage is the average data rate. Therefore, in the present invention, the base station can calculate the outline of each cluster using Equation (11).

), 이로 인해 셀룰러 단말과 수신단말간의 거리와 셀룰러 단말과 송신단말간의 거리는 근사화(

)할 수 있다. 따라서, 수학식 7에서

는

로 근사화되고,

로 정의할 수 있으므로, 수학식 7은 아래 기재된 수학식 10으로 근사화된다. Generally, a cluster shares a channel with a cellular terminal at a remote location. Therefore, the distance between the cellular terminal and the transmitting terminal is infinitely larger than the radius of the cluster (

), Which causes the distance between the cellular terminal and the receiving terminal and the distance between the cellular terminal and the transmitting terminal to approximate (

)can do. Therefore, in Equation (7)

The

Lt; / RTI >

, Equation (7) is approximated by Equation (10) described below.

는 평균(

)과 분산

을 가지는 가우스 랜덤 변수로 수렴된다. 그러면, 많은 수의 Nm(클러스터에 포함된 수신단말)에 대해,

은 아래 기재된 수학식 11로 근사화될 수 있다. Considering the case where Nm (receiving terminal included in the cluster) in the equation (10) is sufficiently large asymptote and using the central limit theorem,

The average (

) And dispersion

To the Gaussian random variable. Then, for a large number of Nm (receiving terminals included in the cluster)

Can be approximated by Equation 11 described below.

Therefore, the base station can calculate the outage probability of each cluster using Equation (11) described below.

의 분포가 주어진 k를 가진 모든 수신단말(n)에 대해 동일하다는 가정하에서,

또한 고정 k에 대해 수신단말(n)에 대해 동일하게 분포되고, d_mn = r이다. 수학식 11에서 평균(

)을 구하기 위해서

를 r의 확률밀도함수(pdf)라 하고,

이고,

정의한다. 여기서

는 채널 이득에 대한 기대치, 즉

과

을 나타낸다. 수신단말의 data rate의 평균(

)은 아래 기재된 수학식 12로 유도될 수 있다.

Is the same for all receiving terminals n having a given k,

Is also uniformly distributed with respect to the receiving terminal (n) for fixed k, and d _mn = r. In Equation 11,

To obtain

Is called a probability density function (pdf) of r,

ego,

define. here

Is the expected value for the channel gain, i. E.

and

. The average of the data rate of the receiving terminal (

) Can be derived by Equation (12) described below.

은 r에 대한 기대치,

이다. 이는 r의 누적 분포 함수 (CDF)는 수학식 2로부터

이고,

이기 때문이다. here,

Expectations for r,

to be. This is because the cumulative distribution function (CDF) of r is calculated from Equation (2)

ego,

.

은 아래 기재된 수학식 13으로 나타낼 수 있다.

Can be expressed by the following equation (13).

,

일 수 있다. here,

,

Lt; / RTI >

는 아래 기재된 수학식 14로 유도될 수 있다.≪ RTI ID = 0.0 >

Can be derived by Equation (14) described below.

일 수 있다. here,

Lt; / RTI >

When the outage probability of the cluster is calculated in step S230, the base station allocates a channel having a maximum sum of the throughputs (ET) of all clusters using the cluster outage probability (S240). At this time, the base station allocates a channel that maximizes the sum of the transmission rates as shown in Equation (15) below.

은 채널 k를 통한 클러스터 m의 유효 처리량,

는 채널할당 지표로,

로 정의되며 채널 k가 클러스터 m에 할당되면

= 1, 그렇지 않으면

= 0이 될수 있다. here,

Is the effective throughput of cluster m over channel k,

Is a channel allocation index,

And channel k is assigned to cluster m

= 1, otherwise

= 0.

을 결정한다. The base station may allocate a channel that maximizes the sum of the throughput (throughput) using a bipartite matching algorithm such as the Hungarian algorithm. That is, for all pairs of channels k and m such that the sum of ET of all clusters in the cell is maximized

.

=

이 되도록 송신전력을 선택하여 할당하고, 수학식 15를 이용하여 채널을 할당할 수 있다. As we have seen, the base station has to be able to maximize the ET of the D2D cluster for each pair of m and k

=

The transmission power can be selected and allocated, and the channel can be allocated using Equation (15).

When the above method is used, there is an effect of reducing the overhead of the base station by allocating the channel using only the positions of the cellular terminal and the transmitting terminal.

3 is a view for explaining a base station allocating resources to multiple D2D clusters according to an embodiment of the present invention.

3, a BS 100 for allocating resources to multiple D2D clusters according to an embodiment of the present invention includes a location information obtaining unit 110, a transmission power allocating unit 120, and a channel allocating unit 130 .

The location information obtaining unit 110 obtains location information of a cellular terminal located in a cell covered by the base station 100 and a transmitting terminal included in each cluster.

The transmission power allocation unit 120 calculates and allocates the transmission power of the transmitting terminal using the location information and the cellular outage probability of the cellular terminal and the transmitting terminal obtained by the location information obtaining unit 110. [ That is, the transmission power allocating unit 120 calculates the distance between the cellular terminal and the transmitting terminal using the location information of the cellular terminal and the location information of the transmitting terminal, calculates Equation 6 using the calculated distance, the cellular outage probability, To calculate the transmission power of the transmitting terminal. At this time, the cellular outage probability may be a predetermined value.

The channel allocation unit 130 calculates the outage probability of the cluster and allocates a channel having the maximum sum of the effective throughputs ET of all the clusters using the cluster outage probability. That is, the channel allocator 130 calculates the average data rate of the receiving terminals using the distance between the cellular terminal and the transmitting terminal and the allocated transmission power, Respectively. Then, the channel allocation unit 130 allocates a channel for maximizing the sum of throughputs of all clusters using a Hungarian algorithm or the like.

Hereinafter, the effect of resource allocation for multiple D2D cluster multicast communication in a cellular network will be described through experimental results.

= 23dBm,

= 15dBm,

= -104 dBm,

= 3.5,

=5 dB로 설정하였다.

가 되도록 P^k _k를 선택하고, D2D 간섭이 없는 셀룰러 아웃티지확률은 P^k _m = 0일때 수학식 3을 통해 획득된

이고,

보다 작다. 모든 클러스터에 동일한 수의 수신단말이 위치한다고 가정하고,

의 충분한 수의 조합을 무작위로 생성하였다. 각 조합에 대해

를 결정하고, CA-FIL(Channel Allocation-Full Information of Device Locations) 방식으로 최대 ET 합을 획득하였다. 또한, 채널(

)을 결정하기 위해

만을 사용한 CA-PIL(Channel Allocation-Partial Information of Device Locations)을 수행하여 수학식 11를 통해

를 획득하고, 수학식 15를 통해 최대 ET 합을 산출하고, 결과로 나온 최대 합계 ET는 CA-PIL(analytic)으로 표시하였다. CA-PIL에 의해 최적으로 결정된

와 함께 CA-FIL에서와 같이 주어진

에 대해 수학식 8의

의 수치 평가를 사용하여 실제 ET 총합을 산출하고, 결과로 나온 합계 ET는 CA-PIL(actual)로 표시하였다. 모든 조합에 대해 위에서 얻은 세 가지 종류의 결과 각각을 평균하여 도 4, 5, 6에 도시하였다. First, r _c = 500 m,

= 23 dBm,

= 15 dBm,

= -104 dBm,

= 3 . 5,

= 5 dB.

Is such that the select ^k P _k, and a cellular-out strategy probability without D2D interference is obtained through _m = 0 when ^k P Equation (3)

ego,

Lt; / RTI > Assuming that the same number of receiver nodes are located in all clusters,

≪ / RTI > were randomly generated. For each combination

And the maximum ET sum was obtained by the CA-FIL (Channel Allocation-Full Information of Device Locations) method. Also,

) To determine

And performs CA-PIL (Channel Allocation-Partial Information of Device Locations) using only < RTI ID = 0.0 >

, And the maximum ET sum is calculated using the equation (15), and the maximum ET obtained as a result is expressed as CA-PIL (analytic). Optimally determined by CA-PIL

As given in CA-FIL with

For equation

, And the resulting total ET was expressed as CA-PIL (actual). For each combination, the results of each of the three types of results obtained above are averaged and shown in Figures 4, 5, and 6.

FIG. 4 is a diagram showing maximum ET sums of CA-FIL and CA-PIL (analytic, actual) for the receiving terminal Nm. Referring to FIG. 4, since the CA-PIL is based on the Gaussian approximation to the average ratio, it can be seen that the analytic evaluation of the ET maximum sum is similar to actual as the number of receiving terminals increases. It can be seen that the CA-PIL provides a reasonable result for resource allocation even when the number of receiving terminals (Nm) is small. CA-FIL provides a larger maximum ET sum than CAPIL with Nm times higher system overhead cost. The maximum ET sum of CA-PIL increases as Nm increases and approaches CA-FIL. This confirms the practical effect of CA-PIL when D2DC supports a large number of receiving terminals.

에 대한 CA-PIL의 ET 최대합을 나타낸 도면이다. 도 5를 참조하면, 더 높은

는 송신단말의 더 높은 전송 전력을 허용하기 때문에 더 높은 ET 최대합을 제공한다는 것을 알 수 있다. 더 작은 클러스터 크기가 더 큰 ET 최대합을 제공한다는 것도 확인할 수 있다. D2DC의 ET 최대합이

에 대해 크게 변하지 않는

의 두 영역이 존재한다. 이것은 D2DC 통신의 작동 매개 변수를 설정할 때 고려해야 할 것이다. Figure 5

0.0 > CA-PIL < / RTI > Referring to Figure 5,

Lt; RTI ID = 0.0 > ET < / RTI > maximum sum because it allows higher transmission power of the transmitting terminal. It can be seen that a smaller cluster size provides a larger maximum ET sum. The maximum ET sum of D2DC is

Largely unchanged for

. This should be considered when setting the operating parameters of the D2DC communication.

6 is a graph showing the maximum ET sum per active D2D cluster. Referring to FIG. 6, when K < M, a cluster selection gain can be obtained by selecting the best K D2D cluster among M candidates to participate in D2D communication. If K> M, the channel selection gain can be obtained by selecting among the K possible channels the best M channels that can be allocated to the D2D cluster. The large difference between K and M leads to a higher selectivity gain and thus to a maximum ET per active D2DC.

The present invention has been described with reference to the preferred embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

100: base station
110: Position information obtaining unit
120: Transmission power allocation unit
130: Channel allocation unit
200: D2D cluster
210: D2D transmitting terminal
220: D2D receiving terminal
300: cellular terminal

Claims (9)

In a system in which at least one cellular terminal and at least one D2D (device-to-device) cluster exist in a cell covered by one base station and one transmitting terminal and a plurality of receiving terminals are located in each D2D cluster, each D2D In a method for allocating resources to a cluster,
The BS obtaining location information of a cellular terminal and a transmitting terminal located in a cell;
Calculating a transmission power of a transmitting terminal using the location information and a predetermined out-of-cellular probability;
The base station calculating an outage probability of the corresponding D2D cluster using the calculated transmission power; And
The BS allocating a channel to each D2D cluster using the calculated outage probability,
The outage probability of the D2D cluster,
And calculating an average of the reception terminal data rates calculated using the distance between the cellular terminal and the transmission terminal and the transmission power of the transmission terminal. The method according to claim 1,
Wherein the step of calculating the transmission power of the transmitting terminal comprises:
The distance between the cellular terminal and the base station, the distance between the transmitting terminal and the base station is calculated using the location information of the cellular terminal and the transmitting terminal, and the distance, the cellular outage probability, Wherein the transmission power of the D2D cluster multicast communication is calculated based on the calculated transmission power. The method according to claim 1,
The step of calculating the outage probability of the D2D cluster includes:
Calculating a distance between the cellular terminal and the transmitting terminal using the location information of the cellular terminal and the transmitting terminal;
Calculating an average of the reception terminal data rates using the calculated distance and the calculated transmission power and calculating an outage probability of the D2D cluster based on the calculated average of the reception terminal data rates A method for resource allocation for multiple D2D cluster multicast communications. The method according to claim 1,
Wherein the assigning of the channel comprises:
Wherein a channel is allocated such that the sum of the throughputs of all the D2D clusters is maximized. 5. The method of claim 4,
Wherein the assigning of the channel comprises:
Wherein a channel is allocated using a bipartite matching algorithm. A location information obtaining unit for obtaining location information of a cellular terminal and a transmitting terminal located in a cell;
A transmission power allocation unit for calculating and allocating a transmission power of a transmitting terminal using the obtained position information and a predetermined cellular outage probability; And
A channel allocation unit for calculating an outage probability of a corresponding D2D cluster using the allocated transmission power and allocating a channel having a maximum throughput sum of all D2D clusters using the calculated outage probability,
The outage probability of the D2D cluster,
Based on an average of the reception terminal data rates calculated using the distance between the cellular terminal and the transmission terminal and the transmission power of the transmission terminal. The method according to claim 6,
Wherein the transmission power allocating unit allocates,
The distance between the cellular terminal and the base station and the distance between the transmitting terminal and the base station are calculated using the location information of the cellular terminal and the transmitting terminal, and the distance, the cellular outage probability, and the transmission power of the cellular terminal, And the transmission power of the resource is calculated. The method according to claim 6,
The channel assigning unit,
Calculating a distance between the cellular terminal and the transmitting terminal using the location information of the cellular terminal and the transmitting terminal, calculating an average of the receiving terminal data rates using the calculated distance and the allocated transmission power, And calculates the outage probability of the D2D cluster based on the average of the terminal data rates. The method according to claim 6,
The channel assigning unit,
Wherein a channel is allocated using a bipartite matching algorithm.

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