KR20160099405A - A signal interference between terminals preventing method in full-duplex wireless network - Google Patents

Abstract

Disclosed is a method for preventing signal interference between terminals in a full-duplex wireless communication network. The method includes the steps of: (a) operating a timer using a selected random number by a plurality of terminals and an AP; (b) when some terminals of the plurality of terminals or the AP detects that a count value of the timer arrives at zero, starting data transmission while the terminals or the AP has a higher priority; and (c) when the plurality of terminals or the AP detects the data transmission corresponding to the higher priority, in a state in which the terminals or the AP has a lower priority, selecting a terminal having a minimum value or a maximum value among values of an interference matrix (S_i,j) and upwardly or downwardly transmitting data, wherein the interference matrix (S_i,j) implies the average intensity of interference when a terminal i receives a signal of a terminal j.

Description

Technical Field [0001] The present invention relates to a method of preventing signal interference between terminals of a full-duplex wireless communication network,

More particularly, the present invention relates to a method for preventing inter-terminal signal interference, and more particularly, to a method for selecting a terminal having a predetermined interference matrix value after selecting a data transmission start priority among a terminal and an AP in a full- To-end signal interference in a full-duplex wireless communication network in which a data transmission start backward side transmits data downward or upward.

Recent explosive growth in mobile traffic has required continued efforts to increase the wireless transmission capacity of mobile networks.

Among them, Single-Channel Full-Duplex (FD) communication is attracting attention as an epoch-making communication method that can greatly improve the radio transmission capacity.

Current wireless communication systems assume Half-Duplex (HD) communication in which a node performs only one operation, either transmission or reception, at a specific time-frequency.

In this case, the uplink transmission and the downlink transmission use separate radio resources, respectively. On the other hand, full-duplex communication means that a node transmits a radio signal while receiving another signal at the same frequency.

Since both the uplink and downlink transmission are performed using the same radio resources, the full-duplex communication can improve the transmission capacity of the radio link up to twice as much as the current HD scheme.

User terminals connected to the same cell in an existing wireless network use orthogonal radio resources such as different frequencies and time slots, so that there is no interference between them.

However, there is a problem in that interference may occur between user terminals even in a cell in a full duplex wireless network.

FIG. 1 is a schematic diagram of a full duplex wireless communication system in which inter-terminal interference occurs in a communication in a general full duplex mode based wireless network, in which a plurality of terminals 100-1, 100-2, and 100- And an access point (AP).

As shown in FIG. 1, when an access point (AP) performs uplink and downlink communication with the first and second terminals 100-1 and 100-2, The signal transmitted from the terminal 1 (100-1) acts as an interference to the terminal 2 (100-2) because transmission of the terminal 100-1 and reception of the terminal 2 (100-2) are performed.

If the two terminals are close to each other, this interference can greatly affect the wireless communication performance of transmitting and receiving wireless data.

Therefore, it is possible to stably perform wireless communication not only between terminals having a small interference with each other in a full-duplex wireless communication network but also between terminals having a wide range of possible interference between terminals, It is inevitable to develop a technology capable of efficiently performing communication.

(Patent Document 1) KR10-2014-0010377 A

(Patent Document 2) KR10-2011-0060304A

An object of the present invention is to provide a method and apparatus for selecting a terminal having a predetermined value among interference matrix values when a terminal or an AP activates a timer in a full duplex wireless communication network, Terminal signal interference in a full-duplex wireless communication network capable of preventing inter-terminal signal interference by transmitting an uplink signal or an uplink signal.

The problem to be solved by the present invention is not limited to the above-mentioned problem (s), and another problem (s) not mentioned can be clearly understood by a person skilled in the art from the following description.

According to another aspect of the present invention, there is provided a method for preventing inter-terminal signal interference in a full duplex wireless communication network including: (a) operating a timer using a random number selected by a plurality of terminals and an AP; (b) when a predetermined terminal or the AP among the plurality of terminals detects that the count value of the timer has reached 0, starting to transmit data on a priority side; And (c) if the plurality of terminals or the AP detects the data transmission on the priority side, selects a terminal having a minimum value or a maximum value among the values of the interference matrix (S _{i, j} ) The interference matrix S _{i, j} means an average interference strength when the terminal i receives the signal of the terminal j.

In order to achieve the above object, a method for preventing inter-terminal signal interference in a full duplex wireless communication network according to the present invention includes: measuring a signal strength of another terminal before the step (a); And reporting the measured signal strength information of the other terminal to the AP.

To achieve the above object, a method for preventing inter-terminal signal interference in a full-duplex wireless communication network according to the present invention includes the steps of operating the timer for the selected random number time when the predetermined terminal is on the priority side in step (b) ; Determining whether the predetermined terminal has reached a count value of the timer of 0; When the count value of the timer reaches 0, the predetermined terminal starts data transmission; And selecting a terminal having the minimum value or the maximum value of the interference matrix value and transmitting the downlink when the AP detects data transmission of the predetermined terminal.

In order to achieve the above object, the step (c) of the method for preventing inter-terminal signal interference in a full-duplex wireless communication network according to the present invention comprises the steps of: (c-1) Selecting a terminal having the terminal; And (c-2) selecting a terminal having the maximum value of the interference matrix value if the inter-terminal interference matrix is higher than the interference matrix with the AP by a predetermined gap or more.

To achieve the above object, a method for preventing inter-terminal signal interference in a full-duplex wireless communication network according to the present invention includes: decoding a signal of a predetermined terminal through sequential interference cancellation; And removing the decoded signal from the data transmitted signal and decoding the signal of the AP.

To achieve the above object, there is provided a method for preventing inter-terminal signal interference in a full-duplex wireless communication network in which, when the AP is located on the priority side in step (b), a plurality of terminals, Identifying a terminal that has transmitted data; Calculating a new value from the maximum and minimum interference intensities of the terminals detected by the AP, and generating a random number and comparing the calculated value with the calculated value; And transmitting, by the terminal i, the data to the AP, the generated random number being smaller than the calculated value among the plurality of detected terminals.

In order to accomplish the above object, the present invention provides a method for preventing inter-terminal signal interference in a full-duplex wireless communication network, wherein the terminal i has a first equation (a / min_j {S _{i, j} } _, a is a constant) a * max_j {S _{i, j} } _{, where} a is a constant); Calculating a maximum value among calculation results of the first and second equations; And generating a random number by the terminal i and comparing the random number with the maximum value.

In order to achieve the above object, the step (c) of the method for preventing inter-terminal signal interference in a full-duplex wireless communication network according to the present invention comprises the steps of: (c-1) Selecting a terminal having the terminal; And (c-2) selecting a terminal having the maximum value of the interference matrix value if the interference matrix with the AP is higher than the inter-terminal interference matrix by a predetermined gap or more.

To achieve the above object, the present invention provides a method for preventing inter-terminal signal interference in a full-duplex wireless communication network, comprising the steps of: (a) decoding a signal of an AP through sequential interference cancellation; And removing the decoded signal from the data-transmitted signal and decoding the signal of the terminal i.

The details of other embodiments are included in the detailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and / or features of the present invention and the manner of achieving them will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. And is provided to fully explain the scope of the present invention to those skilled in the art.

According to the present invention, it is possible to overcome the limitation that only a communication with a terminal having a small interference in a full-duplex mode wireless communication network can be overcome, and stable wireless communication can be performed even among a wide range of terminals with possible inter-terminal interference.

In addition, it is possible to efficiently perform communication between the access point and a plurality of terminals in the full duplex wireless communication, thereby improving the yield.

FIG. 1 is a schematic diagram of a full duplex wireless communication system in which inter-terminal interference occurs in a communication in a general full duplex mode wireless network.
2 is a flowchart illustrating an overall operation of a method for preventing inter-terminal signal interference in a full duplex wireless communication network according to the present invention.
FIG. 3 is a schematic configuration diagram of a full duplex wireless communication system showing a case where the terminal 1 (100-1) is discriminated as a priority side in the step S106 of the operation of the inter-terminal signal interference prevention method shown in FIG.
4 is a flowchart showing the operation in the case where the terminal 1 (100-1) is discriminated to the priority side in the step S106 of the operation of the inter-terminal signal interference prevention method shown in Fig.
FIG. 5 is a schematic configuration diagram of a full duplex wireless communication system showing a case where an access point (AP) is discriminated as a priority side in step S106 of the operation of the inter-terminal signal interference prevention method shown in FIG.
6 is a flowchart showing an operation in a case where an access point (AP) is determined as a priority side in step S106 of the operation of the inter-terminal signal interference prevention method shown in FIG.

Hereinafter, a method for preventing inter-terminal signal interference in a full-duplex wireless communication network according to the present invention will be described with reference to the accompanying drawings.

2 is a flowchart illustrating an overall operation of a method for preventing inter-terminal signal interference in a full duplex wireless communication network according to the present invention.

1 and 2, an overall operation of a method for preventing inter-terminal signal interference in a full-duplex wireless communication network according to the present invention will be described.

First, an access point (AP) manages the influence of interference between connected terminals by using an interference matrix (S).

That is, the element S _{i, j} of the interference matrix S _{i, j} means the average interference strength when the terminal i receives the signal of the terminal j.

In this case, since the terminal 0 means an access point (AP), the interference matrix S _{i, 0} is an average interference intensity when the terminal i receives a signal of the access point AP.

In order to acquire such information, a plurality of terminals measures the signal strength of the other terminal (S101), and reports the signal strength information of the other terminal measured by itself to the access point (AP) (S102).

At this time, information of other terminals not reported by the terminal is set to a specific threshold value.

That is, when the terminal i does not receive the signal of the terminal j and does not report the signal, the access point AP sets the interference matrix S _{i, j} to a specific threshold (base lower limit value).

Thereafter, it is determined whether there is data to be transmitted among the terminal and the access point (AP) (S103).

If there is data to be transmitted, the plurality of terminals and the AP operate the timer using the selected random number (S104).

If it is detected that the count value of the timer has reached 0, data transmission is started (S105). Through this operation, the terminal or AP that has first started transmission in the wireless channel becomes the data transmission start priority side.

When the data transmission start side of the terminal and the access point AP detects data transmission on the priority side (S106), a terminal having the minimum or maximum value of the interference matrix (S _{i, j} ) is selected (S107).

The downstream side transmits data to the selected terminal or transmits it to the access point (AP) (S108).

FIG. 3 is a schematic configuration diagram of a full duplex wireless communication system showing a case where the terminal 1 (100-1) is discriminated as a priority side in the step S106 of the operation of the inter-terminal signal interference prevention method shown in FIG.

4 is a flowchart showing the operation in the case where the terminal 1 (100-1) is discriminated to the priority side in the step S106 of the operation of the inter-terminal signal interference prevention method shown in Fig.

When the terminal 1 (100-1) starts uplink transmission first and the access point (AP) starts downlink transmission for a full-duplex mode after a certain time, the terminal 1 (100-1) Is determined by the existing link layer protocol.

For example, in the IEEE 802.11 wireless LAN, a plurality of terminals select a random number for each terminal (S110) and operate a timer for the number of times (S120).

The terminal 1 (100-1) determines whether the count value of the timer has decreased to 0 (S130).

If the count value of the timer reaches 0, the terminal 1 (100-1) starts data transmission (S140).

When the access point AP detects data transmission of the terminal 1 (100-1) (S150), the access point AP compares the values of the interference matrix S _{i, 1} of the interference matrix S _, (S160) and performs downlink transmission (S180).

At this time, when the access point AP selects the terminal having the lowest interference matrix S _{i, 1} (S170), the terminal 1 100-1 gives the lowest interference to the terminal 2 100-2 It is because we expect it.

On the other hand, the highest interference matrix (S _{i, 1)} with the case of selecting the terminal to the terminal 2 (100-2) (S175), the interference than the interference matrix (S _2,0) matrix (S _2,1) is constant It should be higher than the gap.

This is because the signal received from the terminal 1 (100-1) is stronger than the signal received from the access point (AP) by the terminal 2 (100-2) and decodes the signal of the terminal 1 (100-1) first (S176) It is supposed that it is possible to successfully decode the signal of the access point AP (S177) by removing it from the received signal through successive interference cancellation (SIC).

If a terminal having the lowest value among the interference matrices S _{i, 1} , or a terminal having the highest value, or a plurality of terminals in these two cases, a random terminal is selected or a data transmission rate , The quality of service of the scheduler, the total gain, and the like.

FIG. 5 is a schematic configuration diagram of a full duplex wireless communication system in which an access point (AP) is discriminated as a priority side in step S103 of the operation of the inter-terminal signal interference prevention method shown in FIG.

FIG. 6 is a flowchart showing the operation in the case where the access point AP is discriminated as the priority side in the step S103 of the operation of the inter-terminal signal interference prevention method shown in FIG. 2. FIG.

When the access point AP first starts the downlink transmission (S210) and the terminal 1 (100-1) performs the uplink transmission for the full duplex mode after a predetermined time, the access point (AP) (S220), which is the target terminal of the AP transmission.

(A / min_j {S _{i, j} } _, a is a constant) and the second equation (a * max_j {S _{i, j} } _, a is a constant) in a terminal i among a plurality of terminals detected _, And then calculates a maximum value among the two values (S230).

Then, the terminal selects a random number in a predetermined range, for example, [0, 1] (S240), and compares the calculated value and the random number (S250).

If the random number is smaller than the calculated value, the corresponding terminal i performs uplink transmission to the AP (S260), and otherwise does not perform transmission.

This is because there is a high possibility that the terminal 1 (100-1) that gives the highest or lowest interference to the terminal 2 (100-2) performs uplink transmission.

The signal received from the access point AP is stronger than the signal received from the terminal 100-1 by the terminal 2 100-2 so that the signal received from the access point AP) of the mobile station.

The signal received from the terminal 1 (100-1) is stronger than the signal received from the access point (AP) so that the terminal 2 (100-2 ) because of the expected to successfully decode a signal AP removed after decoding the signal before it through the successive interference cancellation (Successive interference Cancellation, SIC) in the received signal.

As described above, in the full duplex wireless communication network, when the priority of the terminal and the AP starts data transmission, the terminal or the AP that receives the data selects the terminal having the predetermined value among the interference matrix values by sensing the priority, To-end signal interference in a full-duplex wireless communication network capable of preventing inter-terminal signal interference by transmitting or receiving upstream or downstream data on a transmission start side.

In this way, it is possible to overcome the limitation that only a communication with a terminal having a small interference in a full-duplex wireless communication network can be overcome, and stable wireless communication is possible even among a wide range of terminals that are likely to interfere with each other. In addition, it is possible to efficiently perform communication between the access point and a plurality of terminals in the full duplex wireless communication, thereby improving the yield.

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, It will be understood by those skilled in the art that various changes, modifications, substitutions, and equivalents may be made therein without departing from the spirit and scope of the invention.

100-1, 100-2, and 100-X: a plurality of terminals
AP: access point

Claims (9)

(a) operating a timer using a random number selected by a plurality of terminals and an AP, respectively;
(b) when a predetermined terminal or the AP among the plurality of terminals detects that the count value of the timer has reached 0, starting to transmit data on a priority side; And
(c) if the plurality of terminals or the AP detects the data transmission on the priority side _, it selects a terminal having a minimum value or a maximum value among the values of the interference matrix (S _{i, j} ) Or uplink transmission,
Wherein the interference matrix S _{i, j} means the average interference strength when the terminal i receives the signal of the terminal j.
A method for preventing interference between terminals of a full duplex wireless communication network.
The method according to claim 1,
Before the step (a)
Measuring a signal strength of the other terminal by the plurality of terminals; And
Reporting the measured signal strength information of the other terminal to the AP;
Lt; RTI ID = 0.0 > 1, < / RTI &
A method for preventing interference between terminals of a full duplex wireless communication network.
The method according to claim 1,
In the step (b)
Activating the timer for a time of the selected random number when the predetermined terminal is on the priority side;
Determining whether the predetermined terminal has reached a count value of the timer of 0;
When the count value of the timer reaches 0, the predetermined terminal starts data transmission; And
Selecting a terminal having the minimum value or the interference matrix value of the maximum value and transmitting the downlink if the AP detects data transmission of the predetermined terminal;
≪ / RTI >
A method for preventing interference between terminals of a full duplex wireless communication network.
The method of claim 3,
The step (c)
(c-1) selecting a terminal having the minimum value of the interference matrix value if it is expected to give the lowest interference among the terminals; And
(c-2) selecting a terminal having the maximum value of the interference matrix value if the inter-terminal interference matrix is higher than the interference matrix with the AP by a predetermined gap or more.
A method for preventing interference between terminals of a full duplex wireless communication network.
5. The method of claim 4,
The step (c-2)
Decoding a signal of the predetermined terminal through sequential interference cancellation; And
Removing the decoded signal from the data transmitted signal and decoding the signal of the AP;
≪ / RTI >
A method for preventing interference between terminals of a full duplex wireless communication network.
The method according to claim 1,
In the step (b)
When the AP is on the priority side,
Identifying a terminal to which the AP has transmitted data, the plurality of terminals sensing transmission of the AP;
Calculating a new value from the maximum and minimum interference intensities of the terminals detected by the AP, and generating a random number and comparing the calculated value with the calculated value;
Transmitting, by the terminal i, the data to the AP, the generated random number being smaller than the calculated value among the plurality of detected terminals;
≪ / RTI >
A method for preventing interference between terminals of a full duplex wireless communication network.
The method according to claim 6,
Wherein the terminal i calculates a first equation (a / min_j {S _{i, j} } _, a is a constant) and a second equation (a * max_j {S _{i, j} } _, a is a constant); And
Calculating a maximum value among calculation results of the first and second equations;
Generating a random number by the terminal i and comparing the random number with the maximum value;
Lt; RTI ID = 0.0 > 1, < / RTI >
A method for preventing interference between terminals of a full duplex wireless communication network.
8. The method of claim 7,
The step (c)
(c-1) selecting a terminal having the minimum value of the interference matrix value if it is expected to give the lowest interference among the terminals; And
(c-2) selecting a terminal having the maximum value of the interference matrix value if the interference matrix with the AP is higher than the inter-terminal interference matrix by a predetermined gap or more.
A method for preventing interference between terminals of a full duplex wireless communication network.
9. The method of claim 8,
The step (c-2)
Decoding the signal of the AP first through sequential interference cancellation; And
Removing the decoded signal from the data transmitted signal and decoding the signal of the terminal i;
≪ / RTI >
A method for preventing interference between terminals of a full duplex wireless communication network.

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