KR101404058B1 - Method and apparatus for interference mitigation between heterogeneous wireless communication systems - Google Patents

Abstract

Disclosed are a method and apparatus for reducing interference due to a heterogeneous wireless communication system using the same frequency band executed by a wireless terminal. The method for reducing the interference due to the heterogeneous wireless communication system using the same frequency band executed by the wireless terminal includes the steps of: dividing and setting the frequency band for packet transmission into K sub frequency bands; sensing a signal level according to each sub frequency band comprising the K sub frequency bands; obtaining interference information according to each sub frequency band; and determining a channel encoding rate based on the interference information.

Description

[0001] The present invention relates to a method and apparatus for interference mitigation between heterogeneous wireless communication systems,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wireless communication, and more particularly, to a wireless communication apparatus to which an interference mitigation method and a method in a heterogeneous wireless communication system can be applied.

2. Description of the Related Art [0002] Recently, various wireless communication systems have been introduced and used through the rapid development of wireless communication technology. The wireless communication system transmits information such as signals, codes, images, and sounds through the airwaves by using the air as a medium in comparison with a wired communication system.

As information technology is introduced into the society, the transmission / reception of information through the wireless communication system is rapidly increasing, and accordingly, a study has been made on a method of efficiently using frequency resources, which are finite resources.

The frequency band that can be used for wireless communication is limited by various reasons such as physical characteristics, related laws, regulations, and regulations. Therefore, when the heterogeneous wireless communication system uses the same frequency band or a part of the used frequency band overlaps Situations can arise.

When different types of communication systems use the same frequency band, the signal of any communication system may cause a problem of interference between communication systems operating as noise to other communication systems using the same frequency band due to the characteristics of the wireless communication system .

The problem of interference between communication systems can be a problem with use and abandonment of the corresponding frequency band and can act as a limitation on the bandwidth of the usable channel. Also, if interference is severe depending on the degree of interference, modulation and coding rate and output are affected in transmission using the corresponding frequency band, which may result in lower reliability and channel capacity of transmission over the corresponding frequency band.

Reducing interference in wireless communication systems is a very important issue in order to efficiently use limited frequency resources and increase transmission reliability. Wireless communication systems employ methods to reduce interference and minimize interference. In the wireless communication system, it is assumed that an entity schedules a transmission / reception schedule of a terminal participating in a wireless communication system, or if a channel to be used before each packet is transmitted is available, And a method of avoiding a collision by reserving packet transmission when it is being used is an example. In addition, a method of minimizing interference by forming and transmitting a beam through a directional antenna, and a cognitive communication method in which a frequency band to be transmitted is adaptively changed according to a situation is applied.

Conventional interference avoiding methods are used for avoiding collision in packet transmission between homogeneous communication systems or when a system having usage right of a specific frequency band is not used and a corresponding frequency band is not used, There are certain limitations in the way they are used. Therefore, there is a need to consider interference mitigation methods that can reduce interference between heterogeneous wireless communication systems using the same frequency band.

The present invention provides a method for reducing interference between heterogeneous wireless communication systems in which the same or a part of the used frequency bands overlap.

In addition, the present invention provides a wireless communication system in which a terminal of a wireless communication system having a relatively short transmission distance in a frequency band used by a heterogeneous wireless communication system having a different coverage transmits, for each band of a wireless communication system having a relatively long transmission distance, It provides a method for measuring strength and interference and using it for its own operation.

A wireless communication system having a relatively short transmission distance in a frequency band where interference between heterogeneous wireless communication systems can occur can minimize a mutual interference to thereby increase the reliability of transmission and at the same time provide a maximum rate of channel coding rate determination do.

According to an aspect of the present invention, a method for mitigating interference by a heterogeneous wireless communication system using the same frequency band performed by a wireless terminal is disclosed.

The interference mitigation method according to an embodiment of the present invention includes a sub frequency band setting step of dividing and setting a frequency band used for packet transmission into K sub frequency bands, And a channel coding rate determining step of determining a channel coding rate based on the interference information.

The interference information may include a probability that a terminal of the heterogeneous communication system transmits a packet through each of the sub-frequency bands.

The channel coding rate may be determined by discarding data transmitted through a sub-frequency band having a predetermined threshold interference or more by a receiving terminal and decoding data transmitted only through data transmitted through a sub- The channel coding rate can be determined.

The interference information can be obtained from the interference of the pilot pattern of the sub-frequency band signal.

The transmission distance of the wireless terminal may be shorter than the transmission distance of the terminal of the heterogeneous wireless system.

The width of the frequency band used by the wireless terminal for packet transmission may be larger than the width of the frequency band used by the heterogeneous wireless system.

The wireless terminal may be a terminal of a wireless LAN system, and the heterogeneous communication system may be a WMAN system.

According to another aspect of the present invention, a wireless terminal according to an embodiment of the present invention includes a processor and a transceiver operably connected to the processor and configured to transmit or receive a wireless packet, For each of the sub-frequency bands constituting the K sub-frequency bands, and acquires interference information for each sub-frequency band by detecting a signal level for each sub-frequency band constituting the K sub-frequency bands, And is set to determine the coding rate.

The interference mitigation method according to the present invention can reduce the interference between heterogeneous wireless communication systems in which the same or a part of the used frequency bands are overlapped to increase the reliability and achieve a high data rate. As a result, efficient utilization of frequency resources can be achieved.

FIG. 1 illustrates a case where a WLAN terminal receives interference from a WMAN terminal during packet transmission.
2 illustrates the received signal strength for each bandwidth different from whether the packet transmission / frequency of the near terminal and the far terminal is different.
3 shows a pilot pattern of the wireless LAN system (IEEE 802.11a).
4 illustrates an example of a communication environment to which the present invention can be applied.
FIG. 5 is a graph illustrating a comparison between methods using a fixed channel coding rate and a method of selecting and transmitting an appropriate channel coding rate according to a given interference situation.
FIG. 6 is a graph showing the amount of normalized data transmission according to an increase in the probability that transmission of a remote terminal will start during one slot.
7 is a block diagram illustrating a configuration of a short-range terminal to which an interference mitigation method according to an embodiment of the present invention can be applied.

While the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and similarities. 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.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In addition, numerals (e.g., first, second, etc.) used in the description of the present invention are merely an identifier for distinguishing one component from another.

Also, in this specification, when an element is referred to as being "connected" or "connected" with another element, the element may be directly connected or directly connected to the other element, It should be understood that, unless an opposite description is present, it may be connected or connected via another element in the middle.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate a thorough understanding of the present invention, the same reference numerals are used for the same means regardless of the number of the drawings.

The same kind of wireless communication devices having the same transmission distance can avoid collision by recognizing the other party to transmit. However, when heterogeneous wireless communication systems having different transmission distances coexist in the same frequency band, (Hereinafter referred to as a near terminal) may be severely interfered by a terminal (hereinafter referred to as a remote terminal) of the remote wireless communication system.

Hereinafter, the long-range wireless communication system and the short-range wireless communication system are based on a relative comparison of the coverage area of the communication system in a relative concept. For example, when a wireless communication system is classified into a wireless personal area network (WPAN), a wireless local area network (WLAN), a wireless metropolitan area network (WMAN), and a wireless wideband area network (WWAN) May be a short range communication system in the context of a WMAN wireless communication system, but may be a vigorous communication system in relation to a WPAN wireless communication system. In some cases, the wireless communication system classified as WMAN may be a long-distance communication system and a short-distance communication system depending on the shortest distance of the transmission distance.

A remote terminal of a remote communication system and a near terminal of a near system mean a terminal operating in each communication system which is a relative concept, and a remote terminal and a near terminal are not necessarily physically distinguished. For example, a wireless terminal supporting the WCDMA, LTE protocol of the 3GPP standard classified as the WAN, the wireless LAN protocol of the IEEE802.11 standard classified as the WLAN, and the Bluetooth protocol of the IEEE802.15 standard may be connected to a remote terminal or a near- .

Hereinafter, the WLAN terminal will be described as an example of a remote terminal and the WLAN terminal will be described as an example of a local terminal. However, as described above, And it does not mean that the interference mitigation method of the present invention can be applied to a specific communication system. The distinction between a near terminal and a remote terminal is also intended to clarify the technical structure and effects of the present invention more clearly and to facilitate understanding, but the present invention does not necessarily presuppose a difference in transmission distance.

While a packet of a remote terminal (for example, a terminal supporting the WMAN terminal or the IEEE 802.16 (mobile wimax) standard) is transmitted, a local terminal (for example, a WLAN terminal) recognizes the transmission of the remote terminal, While the packet of the terminal is being transmitted, the remote terminal does not recognize the packet transmission of the near terminal, so that it can start transmitting its own packet and consequently disturb the packet transmission of the near terminal. As a result, the communication of the near terminal is seriously interfered and the packet transmission is not properly performed.

In this situation, if the near terminal uses the same or narrower bandwidth than the remote terminal, packet transmission is impossible when there is interference of the remote terminal (packet transmission of the remote terminal). However, if the bandwidth of the near terminal is wider, it is possible to transmit data according to the channel coding rate since there is a band used by a near terminal that is not used for packet transmission of a band-interference terminal.

Generally, a short distance terminal is less burdened on transmission power and frequency reuse can be dense, so using a wide bandwidth may not be a relatively large burden compared to a remote terminal. For example, when a WLAN terminal and a WMAN terminal coexist at 3.65 GHz, a WMAN terminal uses a bandwidth of 5 MHz, while a WLAN terminal uses a bandwidth of a maximum of 20 MHz.

If the near terminal can use a wider bandwidth than the far terminal, the near terminal can mitigate the interference using the low channel coding rate. FIG. 1 illustrates a case where a WLAN terminal receives interference from a WMAN terminal during packet transmission. If the bandwidth of the near terminal is wider than the bandwidth of the remote terminal, there is a band that is not interfered. Therefore, even when there is interference due to packet transmission of the far terminal by using proper channel coding rate - generally low channel coding rate Do. However, when the low channel coding rate is used, the data rate is lowered. Therefore, it is necessary to use an appropriate channel coding rate considering the loss of the data rate.

Considering only the same wireless communication system without consideration of a heterogeneous wireless communication system, there are two cases when packet transmission fails: (1) transmission failure due to bad channel, and (2) collision with another local terminal And the like.

In case (1), the strength of the received signal is insufficient. In this case, the data rate is usually lowered to solve the problem. The wireless communication system has a plurality of selectable predetermined data transmission rates and can select and transmit a data transmission rate according to the strength of the received signal. The data rate is mainly determined by the modulation method. If the signal intensity is low, a low modulation scheme such as BPSK or QPSK, or a high modulation scheme such as 16QAM or 64QAM when the signal intensity is high can be used. However, it may be necessary to use a very low channel coding rate in the presence of interference from the far-end terminal, but in general, the wireless communication device does not provide such a function (a combination of a high modulation scheme and a low channel coding rate generally does not exist ) There is no method for determining the channel coding rate.

In case (2), there is interference from another wireless communication device. In this case, the WLAN terminal increases the contention window through a binary exponential backoff in order to reduce the congestion. However, in case of interference from the remote terminal, the remote terminal does not receive interference from the near terminal, and therefore, there is no change. On the other hand, only the near terminal-WLAN terminal performs the binary index backoff, thereby degrading the performance of the near terminal.

Since the current method of operating the wireless communication system does not consider the interference from the heterogeneous communication system, when the heterogeneous communication systems coexist, the near terminal is greatly influenced by the communication due to serious interference from the remote terminal.

Hereinafter, a communication environment in which a short distance terminal of a wide area communication system having a wide bandwidth available for packet transmission and a remote terminal of a long distance communication system having a narrow bandwidth available for packet transmission coexist is assumed. In the assumed communication environment, when a near terminal is observing a channel condition without transmitting or receiving a packet, (a) when there is not much packet transmission between a near terminal and a remote terminal, (b) , and (c) when there are many packet transmissions of the remote terminal.

For example, if it is assumed that the bandwidth of the near terminal is N times the bandwidth of the remote terminal, and the received signal strength of the near terminal is measured for each of the N bands, (B), high signal strength is measured in all bands. In (c), the signal strength is high in the specific band and low in the other band. do.

If a small received signal strength is measured in all bands for most of the time, the near terminal maintains a relatively small contention window and a high channel coding rate considering (a). If the high received signal strength is measured in all bands and the signal strength is high only in some bands during the non-negligible time (adaptively determined according to the embodiment, or for a time equal to or greater than a predetermined threshold) It is possible to apply a relatively high contention window and a high channel coding rate. If the high received signal strength is measured only in some bands and the high received signal strength is not measured in all bands for a negligible time, then a small contention window and a low channel coding rate can be applied considering (c) .

Even when receiving a packet, it is possible to check whether there is an interference of a near terminal or an interference of a remote terminal through measurement of an interference signal strength as well as a received signal strength.

3 shows a pilot pattern of the wireless LAN system (IEEE 802.11a).

In FIG. 3, it can be confirmed whether or not the interference is large by comparing similarities of the pilot signals adjacent in time, and it is possible to measure the presence or absence of interference for each band.

When the near terminal fails to transmit a packet, the following three situations can be assumed.

(i) Transmission failed due to bad channel

(ii) transmission failed due to a conflict with another local terminal

(iii) transmission failed due to interference from the remote terminal

According to the embodiment of the present invention, when there is not much interference in all the bands and the received signal strength is low, the near terminal can consider the case of (i) and adjust the data rate, especially MCS, to lower the modulation scheme. If the received signal strength is sufficient but interference is considered to be large for all bands, it is regarded as case (ii) and the contention window is increased through binary index backoff.

If it is determined that the received signal strength is sufficient but the interference is large in some bands, the near terminal may consider the case of (iii) and lower the channel coding rate.

(I) in the case of lowering the channel coding rate, but in the case of (i), the lower channel coding rate is applied without changing the modulation scheme And the like.

Hereinafter, an example of the channel coding rate determination method will be described in more detail.

4 illustrates an example of a communication environment to which the present invention can be applied.

배 넓은 대역폭을 사용한다고 가정하자. 근거리 단말이 패킷 전송에 사용하는 대역폭을

개의 주파수 영역으로 나눌 때

번째 영역에서 수신되는

번째 신호는 수식 1과 같이 쓸 수 있다.In the example of FIG. 4, the near terminal is strongly interfered by the far terminal. The local terminal may further include a remote terminal for alleviating interference from the remote terminal

Suppose you are using a wider bandwidth. The bandwidth used by the near terminal for packet transmission is

When divided into frequency regions

Lt; th >

Th signal can be written as shown in Equation (1).

은 수신신호,

는 채널,

는 송신신호,

은 간섭신호,

는 잡음이며

는 간섭이 있을 경우 1, 간섭이 없을 경우 0이다. In Equation 1

Lt; / RTI >

A channel,

A transmission signal,

Is an interference signal,

Is the noise

Is 1 when there is interference and 0 when there is no interference.

The near terminal estimates the presence or absence of interference for each frequency domain before the received signal is input to the channel decoder, and discards the received signal in the corresponding frequency domain if there is interference. That is, the input signal of the channel decoder of the near terminal is expressed by Equation (2).

As described above, the near terminal can estimate the presence or absence of interference in the received packet by measuring whether the noise is abnormally large in the pilot signal belonging to each frequency region.

The channel code uses a low channel coding rate capable of restoring the discarded received signal so that there is interference in some frequency domain so that communication can be performed even if a signal transmitted in the frequency domain is discarded.

개의 영역 중

개의 영역에 간섭이 있어서 폐기되어

의 데이터가 폐기되었을 때 이를 복원할 수 있는 부호화율을

라 하면, 근거리 단말의 패킷 전송 시 적절한 부호화율

를 선택함으로써 원거리 단말로부터의 간섭이 있는 경우에도 통신이 가능하도록 한다. According to an embodiment of the present invention

Of areas

There are interference in

Of the data is discarded.

, A proper coding rate

So that communication can be performed even when there is interference from the remote terminal.

, 원거리 단말의 간섭이 있을 때 패킷 구간 동안 원거리 단말의 전송이 끝날 확률을

라고 할 때,

개의 주파수 영역 중 간섭이 있는 주파수 영역의 수는 평균적으로

가 된다. 패킷 전송을 시작하기 전

개의 영역 중

개의 영역에 간섭이 있을 때

의 부호화율로 패킷 전송을 시작하였다면 추가로 발생하는 간섭이

이하일 때 전송에 성공하게 된다.

개의 영역 중

개의 영역에 간섭이 있을 때

의 부호화율로 패킷 전송을 시작하였다면

개의 영역은 폐기 되었고 나머지

영역에서

이상의 간섭이 발생하면 전송 실패이므로 전송에 실패할 확률은 수식 3으로 얻어진다.When there is no interference from the remote terminal in a certain frequency domain, the probability that the remote terminal's transmission will start while the packet of the near terminal is transmitted

, The probability of the end of transmission of the remote terminal during the packet interval when there is interference from the remote terminal

When you say,

The number of frequency regions with interference among the frequency regions is averaged

. Before starting packet transmission

Of areas

When there are interference in the area

If the packet transmission starts at the coding rate of

The transmission is successful.

Of areas

When there are interference in the area

If the packet transmission is started at the coding rate of

The zones are discarded and the rest

In the area

If the above interference occurs, since the transmission is failed, the probability of failure in transmission is obtained by Equation (3).

Therefore, when the transmission rate is 1 in an environment with no interference, the transmission rate in an environment with interference is obtained as shown in Equation (4).

를 예측하고, 패킷 전송을 시작하기 전, 간섭이 있는 주파수 영역의 수

을 찾은 뒤, 수식 4의

을 최대화시키는

를 찾아서

의 부호화율로 전송을 한다.The near terminal observes the signal level of each frequency domain while not transmitting, so that the probability that the transmission of the far terminal will start during the packet transmission time

And before starting packet transmission, the number of frequency regions with interference

Then,

Maximizing

To find

Of the transmission rate.

) 일부 주파수 영역으로 전송된 신호가 폐기되었을 때, 복호가 가능한 채널부호화 방법이 있는지 확인하기 위하여 구속장 9, 부호화율 1/3의 길쌈 부호(convolutional code)에서 임의로 데이터를 선택하여 반복시키고 임의로 데이터를 선택하여 폐기하여 부호화율

(즉, 1/3, 1/4, 1/6, 1/12)을 얻었을 때 프레임 오류율(frame error rate, FER) 성능을 살펴보면, 도 4에서 확인할 수 있는 바와 같이 데이터 전송률은

대비 1, 3/4, 2/4, 1/4로 감소시키면서 4개 영역 중 0, 1, 2, 3개의 영역을 임의로 폐기해도 FER 성능은 유사함을 볼 수 있다. In the transmission of a short-range terminal with a bandwidth four times that of a remote terminal (

) When a signal transmitted in some frequency domain is discarded, in order to check whether there is a decodable channel encoding method, data is arbitrarily selected and repeated in convolutional code 9 with a coding rate of 1/3, And then discarded and the coding rate

As shown in FIG. 4, when the frame error rate (FER) performance is obtained when the frame rate is 1/3, 1/4, 1/6, 1/12,

The FER performance is similar even if the 0, 1, 2, or 3 areas of the four areas are arbitrarily discarded while decreasing the contrast to 1, 3/4, 2/4, and 1/4.

FIG. 5 is a graph illustrating a comparison between methods using a fixed channel coding rate and a method of selecting and transmitting an appropriate channel coding rate according to a given interference situation.

를 가정하였으며

는 0.1로 하였고

는 0에서 0.32까지 변화시켰다. 간섭 상황에 따라 적절한 채널부호화율을 사용하는 방법은 패킷 전송 시 간섭이 있는 주파수 영역을 확인하고 수식 4를 이용하여 적절한

값을 선택하여 전송한다.The channel coding rate is

And

Was 0.1

Was changed from 0 to 0.32. The method of using the appropriate channel coding rate according to the interference situation is to check the frequency domain with interference in the packet transmission and use Equation 4

Value is selected and transmitted.

의 증가에 따른 정규화된 데이터 전송량을 보여주는 그래프이다.FIG. 6 is a graph illustrating a probability that a transmission of a far-

The amount of normalized data transmission according to the increase of the data transmission rate.

값 구간을 벗어날 경우 성능이 매우 떨어질 뿐만 아니라 적절한

값 구간에서도 일시적으로 간섭을 받는 주파수 영역이 많고 적음에 적응하지 못하고 고정된 채널부호화율을 사용하므로 성능이 만족스럽지 못한 반면 주어진 간섭 상황에 따라 적응적으로 채널부호화율을 정하는 방법은 고정된 채널부호화율을 사용하는 방법들에 비해서 모든

값 구간에서 우수한 성능을 보임을 알 수 있다.The method of using the fixed channel coding rate is appropriate

Beyond the value range, performance is very poor,

The performance is unsatisfactory because a fixed number of channel coding rates is used because the number of frequency regions which are temporarily interfered with each other is large in the value interval. On the other hand, a method of adaptively setting a channel coding rate according to a given interference situation is called a fixed channel coding In contrast to methods that use rates

It can be seen that the performance is excellent in the value interval.

The interference mitigation method according to an embodiment of the present invention uses a wider bandwidth than a remote terminal in order to effectively mitigate interference when heterogeneous communication systems having different transmission distances coexist and a proper channel coding rate Can be selected and transmitted. The near terminal estimates the interference probability for each frequency domain when not transmitting data, estimates the packet transmission probability of the remote terminal, measures the interference amount for each frequency domain at the time of packet reception, can do. The near terminal and the remote terminal of the heterogeneous communication system can coexist in the same band and the near terminal can operate optimally in a given situation despite the interference of the remote terminal.

7 is a block diagram illustrating a configuration of a wireless device to which an interference mitigation method according to an embodiment of the present invention can be applied. The wireless device 700 may be a WLAN terminal as a near terminal.

The wireless device 700 includes a processor 710, a memory 720, and a transceiver 730. The transceiver 730 is configured to transmit and / or receive packets of the present invention and the processor 710 is operatively coupled to the transceiver 730 to be configured to perform the interference mitigation method described above. When the wireless device 700 is a WLAN terminal, the processor 710 and the transceiver 730 may implement the IEEE 802.11 physical layer and MAC layer.

Processor 710 and / or transceiver 730 may include an application-specific integrated circuit (ASIC), other chipset, logic circuitry, and / or data processing device. The memory 720 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and / or other storage devices. When the embodiment is implemented in software, the above-described techniques may be implemented with modules (processes, functions, and so on) that perform the functions described above. The module may be stored in memory 720 and executed by processor 710. [ The memory 720 may be internal or external to the processor 710 and may be coupled to the processor 710 in a variety of well known means.

The above-described embodiments include examples of various aspects. While it is not possible to describe every possible combination for expressing various aspects, one of ordinary skill in the art will recognize that other combinations are possible. Accordingly, it is intended that the invention include all alternatives, modifications and variations that fall within the scope of the following claims.

700: wireless terminal
710: Processor
720: Memory
730: Transceiver

Claims (10)

A method for mitigating interference in a terminal of a wireless communication system having a relatively short transmission distance among heterogeneous wireless communication systems having different transmission distances,
Determining interference between wireless communication systems based on the strength of the measured signals in a plurality of sub-frequency bands;
Determining whether the interference is caused by the homogeneous radio system or the heterogeneous radio system based on the distribution of the measured signal intensity when it is determined that there is interference between the wireless communication systems; And
Adjusting the channel coding rate according to the determination result
/ RTI >
2. The method of claim 1,
Wherein the at least one of the strength of the received signal and the strength of the interference signal
Interference mitigation method.
2. The method of claim 1,
Determining that there is interference between the wireless communication systems when the received signal strength is greater than a predetermined value in at least one sub-frequency band among the plurality of sub-frequency bands,
/ RTI >
The method of claim 1, wherein the step of determining whether the wireless system is based on the homogeneous or heterogeneous wireless system comprises:
If the received signal strength above the set value is measured in all sub-frequency bands, or if the received signal strength above the set value is measured in all sub-frequency bands and there is interference in all sub-frequency bands, A step of judging that there is
/ RTI >
5. The method of claim 4, wherein the adjusting the channel coding rate comprises:
In case of interference by the homogeneous radio system, a step of applying a higher channel coding rate to the case of no interference
/ RTI >
The method of claim 1, wherein the step of determining whether the wireless system is based on the homogeneous or heterogeneous wireless system comprises:
When a received signal strength of a predetermined value or more is measured in a sub-frequency band of a plurality of sub-frequency bands or a received signal strength of a set value or more is measured in all sub-frequency bands and it is determined that there is interference in a sub- A step of determining that there is interference by the heterogeneous wireless system
/ RTI >
7. The method of claim 6, wherein the adjusting the channel coding rate comprises:
In case of interference by heterogeneous wireless systems, applying a lower channel coding rate compared to the case of no interference
/ RTI >
An apparatus for mitigating interference in a terminal of a wireless communication system having a relatively short transmission distance among heterogeneous wireless communication systems having different transmission distances,
A transceiver for transmitting and receiving a packet; And
Determining interference between the wireless communication systems on the basis of the intensity of the measured signals in the plurality of sub-frequency bands and, when it is determined that there is interference between the wireless communication systems, And determines whether the interference is caused by the heterogeneous wireless system or the heterogeneous wireless system, and adjusts the channel coding rate according to the determination result
And an interference canceller.
9. The apparatus of claim 8,
If the received signal strength above the set value is measured in all sub-frequency bands, or if the received signal strength above the set value is measured in all sub-frequency bands and there is interference in all sub-frequency bands, And a higher channel coding rate is applied than in the case where there is no interference
Interference mitigation device.
9. The apparatus of claim 8,
When a received signal strength of a predetermined value or more is measured in a sub-frequency band of a plurality of sub-frequency bands or a received signal strength of a set value or more is measured in all sub-frequency bands and it is determined that there is interference in a sub- , It is determined that there is interference by the heterogeneous radio system and a lower channel coding rate is applied than when there is no interference
Interference mitigation device.

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