KR101204373B1 - Method for cooperative communication in cooperative communication network - Google Patents

Abstract

The present invention relates to a cooperative communication network including a source node, a destination node and a relay node, and more particularly, to maximize channel capacity in a cooperative communication network including a plurality of source nodes, one relay node, and one destination node. The present invention relates to a method for selecting a source node and a method for selecting a destination node that maximizes channel capacity in a cooperative communication network including one source node, one relay node, and a plurality of destination nodes.
To this end, in a cooperative communication network including at least two source nodes and one destination node, and one relay node relaying the source node and the destination node of the present invention, the cooperative operation maximizes the channel capacity set from the source node to the destination node. The communication method includes a signal-to-noise ratio for a channel established between the source node and the relay node, a signal-to-noise ratio for a channel established between the relay node and a destination node, and a signal-to-noise ratio for a channel established between the source node and the destination node. Calculating an output of the maximum ratio combining at the destination terminal, and calculating channel capacity using the calculated maximum ratio combining.

Description

Cooperative communication method for maximizing channel capacity in cooperative communication network {Method for cooperative communication in cooperative communication network}

The present invention relates to a cooperative communication network including a source node, a destination node and a relay node, and more particularly, to maximize channel capacity in a cooperative communication network including a plurality of source nodes, one relay node, and one destination node. The present invention relates to a method for selecting a source node and a method for selecting a destination node that maximizes channel capacity in a cooperative communication network including one source node, one relay node, and a plurality of destination nodes.

Recently, multiple antenna (MIMO: multiple-input-multiple-output) technology has been proposed to implement a wireless network. However, implementing a wireless network between digital devices using such a multi-antenna technology increases power consumption, increases the size of node devices, reduces portability, and complicates the system structure and costs. In order to solve the problem of the multi-antenna technology, many researches have been conducted on a cooperative communication network in which multiple nodes having a single antenna cooperate to implement the multi-antenna technology in a distributed manner.

1 is a diagram schematically illustrating a cooperative communication network. According to FIG. 1, the cooperative communication network may comprise a relay node R which uses relays for decoding and forwarding data communicated from the source node S to the destination node D. FIG. Therefore, the source node S may be directly connected to the destination node D or through the relay node R. If there are no relay nodes around the source node S, the source node S is directly connected to the destination node D. However, if the source node S is in proximity to the relay node R, or if the use of the relay node R is advantageous in terms of certain metrics such as power consumption, then the node may pass through the relay node R to the base station. Can be connected.

As shown in FIG. 1, in a decoding and forwarding scenario, a series of time frames are utilized, where each time frame has two time slots. In the first time slot, the source node transmits at power level P1, and the relay node and the receiving node receive signals from the source node. In the second time slot, the relay node forwards the signal received from the source node to the receiving node, which receives two signals, i.e., a signal directly received from the source node, in order to take advantage of cooperative diversity between the nodes. And a signal relayed by the relay node.

In such a cooperative communication network, when there are a plurality of source nodes and one delivery-destination node in pairs, techniques through cooperation between source nodes (distributed beamforming or distributed space-time code) Has been studied a lot, but these techniques have the disadvantage that time / frequency synchronization between multiple source nodes must match. And in a cooperative communication network, when there are a plurality of destination nodes and one source-delivery node pair, technologies through cooperation between destination nodes have been studied a lot, and problems similar to those of a plurality of source nodes exist.

However, a source node selection technique in a cooperative communication network in which a plurality of source nodes exist and a destination node selection technique in a cooperative communication network in which a plurality of destination nodes exist have an advantage that such synchronization is not necessary and can be easily implemented in an actual system. Although such a node selection technique has many forms of relay node selection in a cooperative communication network, a destination node is selected in a cooperative communication network in which a plurality of source nodes exist and a source node selection in a cooperative communication network in which a plurality of source nodes still exist. There is no specific discussion of options.

An object of the present invention is to propose a source node selection method for maximizing channel capacity in a cooperative communication network having a plurality of source nodes and one relay-destination node pair.

Another object of the present invention is to propose a destination node selection method for maximizing channel capacity in a cooperative communication network having a plurality of destination nodes and one source-relay terminal pair.

To this end, in a cooperative communication network including at least two source nodes and one destination node, and one relay node relaying the source node and the destination node of the present invention, the cooperative operation maximizes the channel capacity set from the source node to the destination node. The communication method includes a signal-to-noise ratio for a channel established between the source node and the relay node, a signal-to-noise ratio for a channel established between the relay node and a destination node, and a signal-to-noise ratio for a channel established between the source node and the destination node. Calculating an output of the maximum ratio combining at the destination terminal, and calculating channel capacity using the calculated maximum ratio combining.

To this end, in a cooperative communication network including one source node and at least two destination nodes and one relay node relaying the source node and the destination node of the present invention, the channel capacity set from the source node to the destination node is maximized. The cooperative communication method includes a signal-to-noise ratio for a channel established between the source node and the relay node, a signal-to-noise ratio for a channel established between the relay node and a destination node, and a signal-to-noise ratio for a channel configured between the source node and the destination node. Calculating an output of the maximum ratio combining in the destination terminal using; and calculating a channel capacity using the calculated maximum ratio combining.

Channel capacity can be maximized in a cooperative communication network comprising a plurality of source nodes, one relay node and one destination node according to the present invention. In addition, the channel capacity can be maximized in a cooperative communication network including one source node, one relay node, and a plurality of destination nodes.

1 illustrates a cooperative communication network,
2 illustrates a cooperative communication network including a plurality of source nodes, one relay node, and one destination node according to an embodiment of the present invention.
3 illustrates a cooperative communication network including one source node, one relay node, and a plurality of destination nodes according to an embodiment of the present invention.

The foregoing and further aspects of the present invention will become more apparent through the preferred embodiments described with reference to the accompanying drawings. Hereinafter will be described in detail to enable those skilled in the art to easily understand and reproduce through this embodiment of the present invention.

2 illustrates a cooperative communication network including a plurality of source nodes, one relay node, and one destination node according to an embodiment of the present invention. Hereinafter, a process of calculating channel capacity in a cooperative communication network including a plurality of source nodes, one relay node, and one destination node according to an embodiment of the present invention will be described with reference to FIG. 2.

Referring to FIG. 2, in a cooperative communication network, a source node transmits a signal to a destination node in a communication network including a plurality of source nodes, one relay node, and one destination node.

이고, R과 D사이 채널의 순간 신호대 잡음비는

이고, S_i과 D사이 채널의 순간 신호대 잡음비는

이다. In a cooperative communication network, a source node sends a signal to a destination node with the aid of a relay node. The instantaneous signal-to-noise ratio of the channel between S _i and R is

And the instantaneous signal-to-noise ratio of the channel between R and D is

And the instantaneous signal-to-noise ratio of the channel between S _i and D is

to be.

)이며, 다른 하나는 소스 노드에서 중계 노드를 경유하여 목적지 노드로 전송되는 중계 경로 (

)이다. 목적지 단말에서 최대 비율 결합(maximal ratio combining)의 출력

은 하기 수학식 1과 같이 주어진다.If S _i sends a signal and R retransmits, there are two paths from which the signal is sent from the source node to the destination node. That is, one is a direct path (directly transmitted from the source node to the destination node).

And the other is the relay path (transmitted from the source node to the destination node via the relay node).

)to be. Output of maximum ratio combining at destination terminal

Is given by Equation 1 below.

[Equation 1]

을 이용해서 채널 용량(channel capacity)

는 하기 수학식 2와 같이 주어진다.At this time,

Channel capacity using

Is given by Equation 2 below.

&Quot; (2) "

은 하기 수학식 3과 같이 정해진다.Selected to maximize channel capacity

Is determined as in Equation 3 below.

&Quot; (3) "

를 이용하여 통신을 수행하면 채널 용량을 최대화 통해 통신을 하면, 채널 용량을 최대화할 수 있다. Therefore, the source node selected through Equation 3

If communication is carried out using maximizing channel capacity, communication can be maximized.

을 이용한 전체 신호 전송은 도 2에 도시되어 있다. 첫 번째 타임 슬롯(time slot)에는

가 신호를 전송하며, 두 번째 타임 슬롯에는

에 관계없이 중계 노드가 신호를 재전송하게 된다.
Selected by Equation 3

The overall signal transmission using is shown in FIG. In the first time slot

Sends a signal, and in the second time slot

Regardless, the relay node will retransmit the signal.

3 illustrates a cooperative communication network including one source node, one relay node, and a plurality of destination nodes according to an embodiment of the present invention. Hereinafter, a process of calculating channel capacity in a cooperative communication network including one source node, one relay node, and a plurality of destination nodes according to an embodiment of the present invention will be described with reference to FIG. 3.

According to FIG. 3, in a cooperative communication network, a source node transmits a signal to a destination node in a communication network including one source node, one relay node, and a plurality of destination nodes.

이고, R과 D_i사이 채널의 순간 신호대 잡음비는

이고, S과 D_i사이 채널의 순간 신호대 잡음비는

이다. In a cooperative communication network, a source node sends a signal to a destination node with the aid of a relay node. The instantaneous signal-to-noise ratio of the channel between S and R

And the instantaneous signal-to-noise ratio of the channel between R and D _i

And the instantaneous signal-to-noise ratio of the channel between S and D _i

to be.

)이며, 다른 하나는 소스 노드에서 중계 노드를 경유하여 목적지 노드로 전송되는 중계 경로 (

)이다. 목적지 단말에서 최대 비율 결합(maximal ratio combining)의 출력

은 하기 수학식 4와 같이 주어진다.If S sends a signal and retransmits it, there are two paths from which the signal is sent from the source node to the destination node. That is, one is a direct path (directly transmitted from the source node to the destination node).

And the other is the relay path (transmitted from the source node to the destination node via the relay node).

)to be. Output of maximum ratio combining at destination terminal

Is given by Equation 4 below.

&Quot; (4) "

을 이용해서 채널 용량(channel capacity)

는 하기 수학식 5와 같이 주어진다.At this time,

Channel capacity using

Is given by Equation 5 below.

[Equation 5]

은 하기 수학식 6에 의해 산출된다.Selected to maximize channel capacity

Is calculated by the following equation (6).

&Quot; (6) "

을 통해 통신을 하면, 채널 용량을 최대화할 수 있다. Therefore, the destination terminal selected through the equation (6)

Communicating over it maximizes channel capacity.

을 이용한 전체 신호 전송은 도 3에 도시되어 있다. 첫 번째 타임 슬롯(time slot)에는 S가 신호를 전송한다. 두 번째 타임 슬롯에는

에 관계없이 중계 노드가 신호를 재전송하게 된다. 따라서 두 타임 슬롯동안

은 모두 신호를 수신하게 된다.Selected by equation (6)

The entire signal transmission using is shown in FIG. S transmits a signal in the first time slot. In the second time slot

Regardless, the relay node will retransmit the signal. So for two time slots

Will all receive a signal.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the scope of the present invention .

S: source node R: relay node
D: destination node

Claims (6)

A cooperative communication method of maximizing a channel capacity set from a source node to a destination node in a cooperative communication network including at least two source nodes and one destination node, and one relay node relaying the source node and the destination node.
The destination using a signal-to-noise ratio for the channel established between the source node and the relay node, a signal-to-noise ratio for the channel established between the relay node and the destination node, and a signal-to-noise ratio for the channel established between the source node and the destination node Calculating an output of the maximum ratio combining at the terminal;
Calculating channel capacity using the calculated maximum ratio combining;
The output of the maximum ratio combining in a cooperative communication network including L source nodes is calculated by the following equation (7).
&Quot; (7) "

Output of maximum rate combine:

Instantaneous signal-to-noise ratio of the channel between S _i and R:

Instantaneous signal-to-noise ratio of the channel between R and D:

Instantaneous signal-to-noise ratio of the channel between S _i and D:

delete The method of claim 1, wherein the channel capacity is calculated by Equation (8).
&Quot; (8) "

Channel capacity
A cooperative communication method of maximizing a channel capacity set from a source node to a destination node in a cooperative communication network including a source node and at least two destination nodes, and a relay node relaying the source node and the destination node.
The destination using a signal-to-noise ratio for the channel established between the source node and the relay node, a signal-to-noise ratio for the channel established between the relay node and the destination node, and a signal-to-noise ratio for the channel established between the source node and the destination node Calculating an output of the maximum ratio combining at the terminal;
Calculating channel capacity using the calculated maximum ratio combining;
The output of the maximum ratio combining in a cooperative communication network including L destination nodes is calculated by the following equation (9).
[Equation 9]

Output of maximum rate combine:

Instantaneous signal-to-noise ratio of the channel between S and R:

Instantaneous signal-to-noise ratio of the channel between R and D _i :

Instantaneous signal-to-noise ratio of the channel between S and D _i :

delete 5. The cooperative communication method according to claim 4, wherein the channel capacity is calculated by Equation 10 below.
[Equation 10]

Channel capacity

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