KR20060002433A - Method for allocation of safety channel in communication system using orthogonal frequency division multiple access scheme - Google Patents

Abstract

The present invention relates to a stable channel structure applicable to downlink FUSC and uplink PUSC and a method for implementing the same in a communication system using an orthogonal frequency division multiple access scheme. The present invention uses a stable channel. When a terminal to be generated occurs, the serving cell and the neighboring cell generate FUSC subchannels having the same subcarriers using the same cell identifier value, and when the configuration of the FUSC subchannel is completed, the base station of the serving cell uses a stable channel. Determining the number of subchannels for the stable channel based on the number of terminals to be used and the frequency usage state in the current cell; and reserving the determined number of subchannels for the terminal that wants the stable channel and the necessary stable channel. After assigning, subcarriers of the remaining subchannels except the stable channel Renumbering the indices of, and after performing the numbering, the serving cell and the neighboring cell involved in the stable channel configure a FUSC subchannel using subcarriers renumbered using their own cell identifiers; Allocating a stable channel to a terminal that wants a stable channel, and assigning the configured sub-channel to a general terminal that is not. Through this structure, the present invention can provide reliable services to terminals at the cell boundary and reduce interference between cells.

4G, OFDMA, Safety Channel, FUSC

Description

Stable Channel Allocation Method for Communication System using Orthogonal Frequency Division Multiple Access Method [METHOD FOR ALLOCATION OF SAFETY CHANNEL IN COMMUNICATION SYSTEM USING ORTHOGONAL FREQUENCY DIVISION MULTIPLE ACCESS SCHEME}             

1 illustrates a frame structure of an uplink / downlink link in a general wideband orthogonal frequency multiplexing access system;

2 is a diagram illustrating a configuration method of a downlink subchannel in a general wideband orthogonal frequency multiplexing access system;

3 illustrates a tile structure of an uplink in a general wideband orthogonal frequency multiplexing access system;

4 illustrates an embodiment of a stable channel structure applied to downlink according to the present invention;

5 is a diagram illustrating a structure of a transmitter of a neighbor cell base station applied to downlink according to the present invention;

6 is a diagram illustrating a structure of a transmitting device of a serving cell base station applied to downlink according to the present invention;

7 is a diagram illustrating a structure of a receiving device of a terminal using a stable channel applied to downlink according to the present invention;

8 is a view showing another embodiment of the structure of a stable channel applied to the uplink / downlink according to the present invention,

9 is a diagram illustrating the structure of a transmission apparatus of a base station and a terminal for stable channel allocation applied to uplink / downlink according to the present invention;

FIG. 10 is a diagram illustrating the structure of a base station and a receiver of a terminal for stable channel allocation applied to uplink / downlink according to the present invention; FIG.

11 is a diagram schematically illustrating a FUSC subchannel allocation scheme for a terminal using a stable channel in an OFDMA-TDD communication system according to the present invention.

The present invention relates to a communication system (hereinafter referred to as "OFDMA communication system") using an Orthogonal Frequency Division Multiple Access (OFDMA) scheme, in particular, broadband The present invention relates to a stable channel structure applicable to downlink full usage of subchannels (FUSC) and uplink partial usage of subchannels (PUSC) in a time division fourth generation OFDMA communication system, and an operation method thereof.

In general, in the 4th Generation (hereinafter, referred to as '4G') communication system, services having various Quality of Service (hereinafter referred to as 'QoS') having a transmission rate of about 100 Mbps Active research for providing users is in progress. Currently, 3rd generation communication systems generally support transmission rates of about 384kbps in outdoor channel environments with relatively poor channel environments, and up to 2Mbps in indoor channel environments with relatively good channel environments. It supports a transfer rate of about.

Meanwhile, wireless local area network (LAN) systems and wireless urban area network (MAN) systems generally support transmission rates of 20 Mbps to 50 Mbps. Therefore, in the current 4G communication system, a new communication system is developed in a form of guaranteeing mobility and QoS in a wireless LAN system and a wireless MAN system that guarantee a relatively high transmission speed to provide a high-speed service to be provided in the 4G communication system. There is a lot of research going on to support it.

The wireless MAN system is a broadband wireless access (BWA) communication system, which has a wider service area and supports higher transmission speed than the wireless LAN system. Orthogonal Frequency Division Multiplexing (OFDM) and Orthogonal Frequency Division Multiple Access (OFDM) for supporting a broadband transmission network in a physical channel of the wireless MAN system (OFDMA: Orthogonal Frequency Division Multiplexing Access, hereinafter referred to as "OFDMA") is a system that applies the IEEE (Institute of Electrical and Electronics Engineers) 802.16 communication system.

As described above, the OFDM / OFDMA scheme has recently been proposed as a physical layer of a 4G communication system. The OFDM / OFDMA method is a method used in IEEE 802.16 and transmits modulation symbols input in parallel as parallel data. In addition, as the duplex method, frequency division duplexing (FDD) and time division duplexing (TDD) may be used. have.

Next, an uplink / downlink frame structure of the IEEE 802.16d communication system will be described below with reference to FIG. 1 using the IEEE 802.16d communication system as an example.

FIG. 1 is a diagram schematically illustrating the structure of a PUSC and a FUSC of a general IEEE 802.16 TDD-OFDMA communication system.

1, the IEEE 802.16d communication system is a broadband wireless access communication system using a TDD-OFDMA scheme. Since the IEEE 802.16d communication system applies the OFDMA scheme to the wireless MAN system, high-speed data transmission is possible by transmitting a physical channel signal using a plurality of subcarriers.

Referring to FIG. 1, a downlink (DL) 149 and an uplink (UL) 153 are configured by time division. Here, the vertical axis includes a plurality of subchannels 147 and the horizontal axis includes an OFDMA symbol 145. In the downlink 149, the preamble 111 is located at the front end, and then broadcast data information such as the FCH 113, the DL_MAP 115, and the UL_MAP 117 is located, and the downlink is located in the subsequent symbols. Bursts DL_burst 121, 123, 125, 127, and 129 are located. In the uplink 153, preambles 131, 133, and 135 exist in front of each uplink burst UL, bursts 137, 139, and 141, and a ranging subchannel 143 for ranging exists. Information about the position and allocation of the uplink bursts 137, 139, and 141 and the downlink bursts 121, 123, 125, 127, and 129 is informed to the UE through the DL_MAP 115 and the UL_MAP 117. The terminal communicates by receiving a variably allocated subchannel in which a frequency and a symbol are combined every frame. That is, each subframe may use different subchannels instead of fixed subchannels. Since neighboring cells also communicate with each other using the same frequency band, when the cell is in a cell boundary region, when the same subchannel is used in different cells, the neighboring cells may operate as a large interference signal to each other.

In the IEEE 802.16d communication system, the subchannel forming method is different depending on the frequency resource utilization method. That is, the downlink subchannel formation method is a diversity subchannel formation method, and there are FUSC basic specifications and FUSC selection specifications, and PUSC for sector division. There is also an optional AMC subchannel forming method. UL subchannel formation methods include PUSC and AMC. In addition, both the uplink and the downlink can use a stable channel under the AMC subchannel. However, no stable channel configuration under the diversity subchannel has been devised until now.                         

In the current standard (IEEE 802.16d), subchannels can be roughly divided into PUSC subchannels and FUSC subchannels as described above. The PUSC subchannel and the FUSC subchannel may be divided into time divisions on the same frame. FIG. 1 illustrates an example of subcarrier allocation of a cell using a downlink PUSC subchannel and a downlink FUSC subchannel, and an uplink FUSC subchannel and an uplink FUSC subchannel in the IEEE 802.16 OFDMA-TDD system.

Here, the PUSC scheme is a scheme in which only some subchannels are allocated for each sector among all subchannels, and this case corresponds to a case where a frequency reuse factor is greater than one. In this case, different sectors of the PUSC subchannel are allocated to sectors of two adjacent cells to avoid mutual interference between sectors. However, it is difficult for two base stations to allocate a PUSC subchannel having the same subcarrier to a terminal located at a cell boundary.

Next, the FUSC scheme is a scheme in which all subchannels are allocated to all sectors of all cells, and this case corresponds to a case where frequency reuse efficiency is set to one. In the FUSC method, all subchannels can be used in all sectors, but in order to minimize interference between subchannels of each sector, a subcarrier set of subchannels is configured differently for each sector. That is, the FUSC subchannels are designed to minimize the hit probability of the corresponding subcarriers between the subchannels. However, although the same subchannel having the same subcarrier should be allocated in two sectors, the FUSC of the IEEE 802.16d D5 standard currently has a problem that it is difficult to allocate the same subchannel having the same subcarrier in both sectors.

Accordingly, in the present invention, a new stable channel applied to downlink FUSC and uplink PUSC of the wideband wireless orthogonal frequency multiple access communication system, which has been discussed so far, will be described. In addition, the structure and operation of the new stable channel is proposed to ensure the service quality of the terminal existing in the cell boundary area and to minimize interference to the terminal of the neighboring cell.

Therefore, the present invention was devised to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a novel structure and stable operation scheme for stable channel allocation applied to downlink FUSC requirements in a wideband wireless orthogonal frequency multiple access scheme. In providing.

Another object of the present invention is to provide a novel structure and a management method for stable channel allocation applied to downlink FUSC selection in a wideband wireless orthogonal frequency multiple access scheme.

It is still another object of the present invention to provide a novel structure and operation method for stable channel allocation applied to uplink PUSC requirements in a wideband wireless orthogonal frequency multiple access scheme.

It is still another object of the present invention to provide a novel structure and operation method for stable channel allocation applied to uplink PUSC selection in a wideband wireless orthogonal frequency multiple access scheme.

In the present invention for achieving the above object, in a stable channel allocation method in a communication system using an orthogonal frequency division multiple access method,

When a terminal to use a stable channel is generated, the serving cell and the neighboring cell generate the FUSC subchannels having the same subcarriers using the same cell identifier value, and when the configuration of the FUSC subchannel is completed, the base station of the serving cell Determining the number of subchannels for the stable channel based on the number of terminals to use the stable channel and the frequency usage state in the current cell, and reserving the determined number of subchannels for the terminal for the stable channel. After allocating the necessary stable channel, renumbering the indexes of subcarriers of the remaining subchannels except the stable channel; and after performing the numbering, the serving cell and the neighboring cell participating in the stable channel use their own unique cell identifiers. Configuring the FUSC subchannel by using the renumbered subcarriers, And assigning a stable channel to the terminal that wants the stable channel.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.                     

First, when all cells use all the bands in a multi-cell system using the conventional OFDMA scheme, interference signals are received from terminals using the same frequency band located in neighboring cells. Accordingly, by allocating a frequency band not used by neighboring cells to terminals in the border region, cell capacity can be increased by minimizing interference signals from neighboring cells.

In general, a downlink frame of a time division wideband orthogonal frequency multiple access system is defined by grouping several OFDM symbols consecutive in time in one unit. In one frame, the OFDM symbol used as the preamble comes first, followed by the OFDM symbols carrying the broadcast message, followed by the OFDM symbols transmitting the user's data.

In addition, the OFDM symbols for transmitting the user's data are divided into subchannel units, so that each terminal in the cell is assigned one or more subchannels. At this time, the subchannel is composed of a plurality of subcarriers, and the method of configuring a subchannel from physical subcarriers is applied differently to uplink and downlink, and there are various methods according to characteristics of frequency resource utilization.

In the current standard, the FUSC subchannel is configured using two permutations in downlink, and the FUSC subchannel is configured using two permutations in uplink. One of each of these two permutations is necessarily used and the other is optional.

That is, there is a FUSC subchannel as a first method of utilizing downlink frequency resources of the IEEE 802.16d communication system. This is to use one subchannel as a logical unit by combining subcarriers scattered at different positions. Hereinafter, a method of forming an FUSC subchannel from subcarriers constituting an OFDM symbol will be described with reference to FIGS. 2 and 3.

FIG. 2 is a diagram illustrating a configuration method of a downlink subchannel in a general wideband orthogonal frequency multiplexing access system, and FIG. 3 is a diagram illustrating an uplink tile structure in a general wideband orthogonal frequency multiplexing access system.

Referring to FIG. 2, among the subcarriers constituting one OFDM symbol, the remaining data subcarriers except the guard band and the DC carrier are sequentially numbered. The data subcarriers are divided into groups of constant size. In addition, the one subchannel is formed by taking out one subcarrier from each group. The other subchannel is configured by applying the same method to the above from the remaining subcarriers except for the subcarriers used in the above-described subchannel. In addition, there are two methods for extracting subcarriers from each group, as described above, two different permutation formulas, and different distributions of the number of subcarriers shared by two subchannels. .

Next, referring to FIG. 3, the uplink of the IEEE 802.16d communication system forms a subchannel in a tile structure. Essential and optional items are also defined in the tile structure, as shown in FIGS. 3A and 3B, respectively. That is, as shown in FIG. 3A, one requirement is to configure one tile as three symbols and four subcarriers (4 × 3 structure). The 4 x 3 tile includes all 12 subcarriers, of which 4 subcarriers are used as pilot carriers and the remaining 8 subcarriers are used as data carriers. On the other hand, the option is to configure one tile as 3 symbols, 3 subcarriers (3 x 3 structure), as shown in Figure 3b. The tiles of the 3x3 structure all use nine subcarriers, one of which is used as a pilot subcarrier, and the remaining eight subcarriers are used as data subcarriers.

Next, there is an AMC (Adaptive Modulation and Coding) subchannel as a second method of using frequency resources. This is a method of configuring a subchannel by grouping subcarriers in physically contiguous positions into one logical unit.

Hereinafter, in the present invention, when a terminal moves between cells in a multi-cell environment, the terminal receives interference from adjacent cells as the terminal approaches a cell boundary. Therefore, there is a need for a subchannel or subcarrier allocation method that can reduce interference for a limited time while the terminal stays at the cell boundary. Therefore, we propose a stable channel to reduce the influence of interference on the terminal when the terminal using the downlink FUSC subchannel and the uplink PUSC subchannel is located at the cell boundary.

<Example 1>

Embodiment 1 proposes a stable channel allocation method applied to downlink FUSC basics. In the case of the FUSC subchannel of the present invention, the subcarriers constituting the subchannel are determined by permutation, and the rules of the permutation are different for each cell. Therefore, the set of subcarriers constituting subchannel n of cell A and subchannel m of cell B does not match. Hereinafter, these permutations constituting the FUSC subchannel will be described based on the equations.

Equation 1 below is an expression representing an essential permutation constituting the FUSC subchannel in downlink, and shows an example of a subcarrier allocation rule of the diversity subchannel.

는 s번째 서브채널에서의 k번째 부반송파의 부반송파 인덱스를 나타낸 것이다. 상기 s는 FUSC 부채널의 인덱스를 나타낸 것으로

를 가진다. 상기 k는 상기 부채널 s 안에서의 부반송파 인덱스를 나타낸 것으로

를 가진다. 상기

는 FUSC 총 부채널의 개수를 나타내는 값(예컨대, 32)을 의미한다. 상기 n_k는

을 의미한다. 이 때, 상기

은 한 부채널당 부반송파의 개수(예컨대, 48)를 나타낸다. 다음으로, 상기 ID_cell는 셀 식별자(ID: identifier, 이하 "ID"라 칭하기로 한다)를 나타낸 것이다. 상기 p_s는 기본 순열 p₀을 왼쪽으로 상기 s번 사이클릭 쉬프트(s-Cyclic Shift) 하여 얻은 순열을 나타낸 것이다. 여기서 상기 기본 순열 P₀는 다음과 같이 나타낼 수 있다.Where

Denotes the subcarrier index of the kth subcarrier in the sth subchannel. S represents the index of the FUSC subchannel.

Has K denotes a subcarrier index within the subchannel s.

Has remind

Denotes a value (eg, 32) indicating the number of FUSC total subchannels. N _k is

Means. At this time,

Represents the number of subcarriers (eg, 48) per one subchannel. Next, the ID _cell represents a cell identifier (ID: hereinafter referred to as "ID"). The p _s represents a permutation obtained by s-cyclic shifting the basic permutation p ₀ to the left. Here, the basic permutation P ₀ may be represented as follows.

As shown in Equation 1, all cells have their IDs and form different FUSC subchannels through permutations represented by Equation 1 according to this value. In other words, as in the example of the subcarrier allocation rule, two different subchannels in one cell do not share subcarriers, and two subchannels belonging to two different cells are designed to share only a small number of subcarriers. This is to minimize interference between subchannels belonging to different cells.

Next, a method of allocating and using a stable channel by a base station and a terminal using a channel, which is a requirement for downlink FUSC according to the present invention, will be described with reference to FIGS. 4 to 7.

이다. 또한 각 셀의 기지국은 안정적 채널로 사용될 연속된 부반송파의 그룹을 한 개 지정한다.First, as shown in FIG. 2, the allocation rule of the subcarriers is performed by selecting subcarriers one by one from a group consisting of physically continuous subcarriers. If the subcarrier group index is g, the range of g is

to be. In addition, the base station of each cell designates one group of consecutive subcarriers to be used as a stable channel.

First, the case in the adjacent cell will be described. All terminals in the neighboring cell should not use the subchannel s and the subcarrier k obtained by applying the number of the cell to which they belong, that is, the cell number and the group number g of the neighboring cell in Equation 2 below, and the base station of the neighboring cell. Again, information symbols should not be transmitted in subchannel s and subcarrier k obtained by applying its cell number, i.e., the cell number and group number g of an adjacent cell, to Equation 2.

4 shows a method of allocating subcarriers for a stable channel from each subchannel in an adjacent cell using a band corresponding to the group number g as a stable channel. FIG. 5 illustrates a transmitter structure of an adjacent cell having a stable channel according to Embodiment 1, which is applied to downlink FUSC basics.

에 속하는 모든 부반송파의 값을 0으로 하며, 각 부채널의 입력으로 들어오는 데이터 심볼을, 안정적 채널을 구성하는 부반송파들을 제외한 모든 부반송파에 할당하는 기능을 한다. 안정적 채널 부반송파 제거기(503)는 파일럿 심볼 삽입기(504)를 거쳐 역 고속 푸리에 변환(IFFT: Inverse Fast Transform, 이하 "IFFT"라 칭하기로 한다)기(505)로 입력된다.The stable channel subcarrier remover 503 of FIG. 5 is a subcarrier group designated as a stable channel.

All subcarriers belonging to are set to 0, and data symbols coming into the input of each subchannel are allocated to all subcarriers except subcarriers constituting a stable channel. The stable channel subcarrier canceler 503 is input to an inverse fast transform (IFFT) device 505 via a pilot symbol inserter 504.

는 p₀의 역 순열을 나타낸 것으로, 상기 예의 p₀에 대한 역 순열

은 다음과 같이 주어진다.Where

It is intended only to show the inverse permutation of p _0, inverse permutation of the above example p ₀

Is given by

Next, the operation of the serving cell will be described. When the terminal requests the serving base station to use the stable channel, the serving base station informs the terminal of the subcarrier group index g of the neighboring base station to which the terminal is to move. In addition, the base station of the serving cell transmits a data symbol for a terminal that intends to use a stable channel in (s, k) obtained by inputting g and its cell number into Equation 2 above.

4 shows a method of allocating subcarriers for a stable channel from each subchannel in a serving cell using a band corresponding to the group number g as a stable channel. 6 illustrates a structure of a transmitter of a serving base station for allocating a stable channel according to Embodiment 1 applied to downlink FUSC basics.

Referring to FIG. 6, the stable channel 602 of FIG. 6 stores data symbols for a terminal using the channel, and the permutation apparatus 603 includes data symbols for a terminal using the stable channel. In other words, the data of all the other terminals belonging to the serving cell are properly arranged according to the permutation formula. The output of the permutation device 603 is input to the pilot symbol inserter 604, and the output of the pilot symbol inserter 604 is input to the input of the IFFT device 505.

Hereinafter, operations of a terminal belonging to an adjacent base station and a terminal belonging to a serving base station will be described.                     

The terminal belonging to the neighboring base station does not receive the data symbols located at (s, k) obtained by applying the cell number and the group number g of the neighboring base station to Equation 2 above. As a terminal belonging to a serving base station, a terminal that does not use a stable channel does not receive data symbols located at (s, k) obtained by applying the cell number and group number g of the serving cell base station to Equation 2 above. A terminal using a stable channel as a terminal belonging to a serving base station receives data symbols located at (s, k) obtained by applying the cell number and group number g of the serving cell base station to Equation 2 above. 4 shows a method of allocating subcarriers for a stable channel from each subchannel by a terminal of a serving cell using a band corresponding to the group number g as a stable channel.

7 illustrates a receiver structure of a terminal using a stable channel according to the first embodiment applied to downlink FUSC basics.

The output of the Fast Fourier Transform (FFT) 701 of FIG. 7 passes through a pilot tone remover 702 and passes through a symbol demodulator 703. The output of the symbol demodulator 703 is input to the stable channel extractor 704. The stable channel extractor 704 receives the group number of the stable channel held by the neighboring cell and the ID of the serving cell as input factors.

<Example 2>

In Embodiment 2, a new subchannel formation method supporting a stable channel is proposed in the essential requirements of the downlink FUSC subchannel allocation method. A new subchannel forming method that supports a stable channel in the downlink FUSC can be obtained by applying the formula of Equation 3 below in two steps.

는 부채널의 개수(예컨대, 32)를 나타낸 것이고, 상기

는 필요한 안정적 부채널의 개수를 나타낸 것이다. 또한 상기

는 한 부채널당 부반송파의 개수(예컨대, 48)를 나타낸 것이고, 상기 n_k는

를 의미하고, 상기 p_s[i]는 상기 p₀를 왼쪽으로 s번 cyclic shift 한 것의 i번째 값을 나타낸 것이다. 이 때, 상기 i는

을 의미한다. 다음으로, 상기 p₀는 상기

가 0일 경우에는 p와 동일하고, 0 이상의 값일 때는 상기 p로부터

값에 해당하는 원소들을 제거한 후의 순열을 의미한다. 여기서, 상기 p는 다음과 같이 나타난다.Here, s represents the subchannel number, m represents the number of subcarriers in the subchannel,

Denotes the number of subchannels (eg, 32), and

Shows the number of stable subchannels required. Also above

Is the number of subcarriers (for example, 48) per subchannel, and n _k is

P _s [i] represents the i-th value of the cyclic shift of p ₀ to the left by s times. In this case, i is

Means. Next, the p ₀ is the

Is equal to p when 0, and from p above when the value is 0 or more.

The permutation after removing the elements corresponding to the value. Where p is represented as follows.

Next, the ID _cell represents a cell ID.

가 0이 되면 상기한 수학식 1에서와 같은 형태가 됨을 알 수 있다. 이는 후술되는 수학식 4, 5, 6에서도 마찬가지로 적용된다. 즉, 상기에서 제안하는 수학식은 기존의 수식을 그대로 포함하면서 안정적 채널을 위해 필요한 부분을 포함한다. 상기 수학식 3에 대해 좀 더 구체적으로 살펴보면, 안정적 채널을 위해 액티브 셋에 포함된 셀들은 동일한 ID_cell 값을 통해 동일한 FUSC 부채널을 구성해야 한다. 즉, 상기 수학식 3에서 ID_cell과

를 모두 0으로 하고 부채널에 매핑되는 부반송파들을 결정하여 FUSC 부채널을 구성한다. 그런 다음 안정적 채널을 위해 필요한

를 결정하고, 상기 결정된 값에 해당하는 부채널들을 제외한 나머지 부채널들에 부반송파들은 다시 넘버링한다. 그런 다음 사기 ID_cell에는 각 셀 고유의 값을 대입하고, 상기

에는 상기에서 결정된 값을 대입한 후 다시 한번 부채널에 매핑되는 부반송파들을 결정하여 FUSC 부채널을 구성하게 되는 것이다.In Equation 3 described above

When 0 becomes 0, it can be seen that the form as shown in the equation (1). The same applies to the following equations (4), (5) and (6). That is, the above-described equation includes the parts necessary for the stable channel while including the existing equation as it is. Referring to Equation 3 in more detail, cells included in the active set for the stable channel should configure the same FUSC subchannel through the same ID _cell value. That is, the ID _cell and the equation (3)

Set all to 0 and determine the subcarriers mapped to the subchannel to configure the FUSC subchannel. Then you need to get a stable channel

Next, the subcarriers are renumbered in the remaining subchannels except for the subchannels corresponding to the determined value. Then, each cell unique value is assigned to the fraudulent ID _cell.

Next, after substituting the value determined above, the subcarriers mapped to the subchannel are once again configured to configure the FUSC subchannel.

=0으로 두고 상기 수학식 3을 적용시킨다. 그렇게 해서 얻은 부채널 중에서 한개 이상의 부채널을 선택한다. 이것을 안정적 채널로서 보류한다. 두 번째 단계에서는 남은 부채널을 0에서부터 차례로 번호를 다시 넘버링 한다. 다음으 로 서빙 기지국은 자신의 ID_cell(예를 들어, ID_cell=1)과 사용하고자 하는 안정적 부채널의 개수를

으로서 지정한 다음, 상기에서와 같이 번호가 다시 넘버링된 부채널에 상기 수학식 3을 적용하여 새로운 부채널을 형성한다. 이 때, 상기

의 값은 안정적 채널을 사용하고자 하는 단말기의 데이터를 수용할 수 있을 만큼 커야 한다. 인접 기지국은 자신의 ID_cell(예를 들어, ID_cell=2)과 사용하고자 하는 안정적 부채널의 개수를

으로서 지정한 다음, 상기에서와 같이 번호가 다시 넘버링된 부채널에 상기 수학식 3을 적용하여 새로운 부채널을 형성한다. 이렇게 형성된 부채널은 서빙 셀의 기지국과, 인접셀의 기지국에서 안정적 채널이 아닌 채널로서 사용되며, 첫 번째 단계에서 설정된 안정적 채널은 인접 기지국에서 사용되지 않아야 하며, 서빙 기지국은 안정적 채널을 안정적 채널을 사용하고자 하는 단말기에게 할당한다. In other words, in the first step, the serving base station and the neighboring base station may use ID _cell = 0,

Equation 3 is applied while setting = 0. One or more subchannels are selected from the subchannels thus obtained. Hold this as a stable channel. In the second step, the remaining subchannels are renumbered from 0 in order. Next, the serving base station determines its ID _cell (for example, ID _cell = 1) and the number of stable subchannels to use.

Next, Equation 3 is applied to the sub-numbered subchannels as described above to form a new subchannel. At this time,

The value of must be large enough to accommodate the data of the terminal to use the stable channel. The adjacent base station determines its ID _cell (for example, ID _cell = 2) and the number of stable subchannels to use.

Next, Equation 3 is applied to the sub-numbered subchannels as described above to form a new subchannel. The subchannel thus formed is used as a non-stable channel in the base station of the serving cell and the base station of the neighboring cell, and the stable channel set in the first step should not be used in the adjacent base station. Assign to the terminal you want to use.

=0이면 기존의 IEEE 802.16d 통신 시스템의 부채널 할당 공식으로 돌아간다.Meanwhile, above

If = 0, return to the subchannel allocation formula of the existing IEEE 802.16d communication system.

Next, Equations 4, 5, and 6 to be described below are used in the same manner as described above.

<Example 3>

In Embodiment 3, in the selection of the downlink FUSC subchannel allocation method, a new subchannel allocation method supporting a stable channel is proposed. A new subchannel forming method that supports a stable channel in the selection of the downlink FUSC subchannel allocation method can be obtained by applying Equation 4 below in two steps.

는 부채널의 개수(예컨대, 32)를 나타낸 것이고, 상기

는 안정적 채널을 위해 필요한 부채널의 개수를 나타낸 것이다. 또한, 상기 k는

를 의미하고, 상기

은 부채널당 부반송파의 개수(예컨대, 48)를 나타낸 것이고, 상기 k'는 k'=kmod(Nsubch-1)를 의미하고, 상기 c₁은 c₁=ID_cellmodN_subch를 의미하고, 상기 c ₂는 c₂ = [ID_cell/N_subch] 를 의미한다.Here, s represents the subchannel number, m represents the number of subcarriers in the subchannel,

Denotes the number of subchannels (eg, 32), and

Shows the number of subchannels required for the stable channel. In addition, k is

Means, said

Denotes the number of subcarriers (eg, 48) per subchannel, k 'denotes k' = kmod (Nsubch-1), c ₁ denotes c ₁ = ID _cell modN _subch , and c ₂ C ₂ = [ID _cell / N _subch ].

를 의미한다. 또한, 상기 p₁은 상기 p_1,base로부터

을 제거하고 난 후의 순열을 의미한다. 이 때, 상기 p_1,base는 하기와 같다.In addition, p _{1, c1} [i] represents the i-th value of the cyclic shift of p ₁ to the left c ₁ , where i is

Means. In addition, the p ₁ is from the p _{1, base}

Means the permutation after removing. At this time, the p _{1, base} is as follows.

을 제거하고 난 후의 순열을 의미한다. 이 때, 상기 p_2,base는 하기와 같다.Also, the p ₂ is from the p _{2, base}

Means the permutation after removing. At this time, the p _{2, base} is as follows.

는 x와 y를 이진수로 표현한 것을 각 자리수마다 XOR을 적용하여 획득한 값, 예를 들어 x=9=(1001)₂ 이고 y=1=(0001)₂이면, 상기

는

=(1000)₂=8이 된다.Next, the ID _cell represents a cell ID,

Is a value obtained by applying XOR to each digit of the representation of x and y in binary, for example, x = 9 = (1001) ₂ and y = 1 = (0001) _2.

Is

= (1000) ₂ = 8

를 모두 0으로 하고 부채널에 매핑되는 부반송파들을 결정하여 FUSC 부채널을 구성한다. 그런 다음 안정적 채널을 위해 필요한

를 결정하고, 상기 결정된 값에 해당하는 부채널들을 제외한 나머지 부 채널들에 부반송파들은 다시 넘버링 한다. 그런 다음 상기 ID_cell에는 각 셀 고유의 값을 대입하고, 상기

에는 상기에서 결정된 값을 대입한 후 다시 한번 부채널에 매핑되는 부반송파들을 결정하여 FUSC 부채널을 구성하게 되는 것이다.Referring to Equation 4 in more detail, cells included in the active set for the stable channel should configure the same FUSC subchannel through the same seed value. That is, the ID _cell and the equation (4)

Set all to 0 and determine the subcarriers mapped to the subchannel to configure the FUSC subchannel. Then you need to get a stable channel

Next, the subcarriers are renumbered in the remaining subchannels except for the subchannels corresponding to the determined value. Then, a unique value of each cell is substituted into the ID _cell , and the

Next, after substituting the value determined above, the subcarriers mapped to the subchannel are once again configured to configure the FUSC subchannel.

=0으로 두고 상기 수학식 4를 적용시킨다. 그렇게 해서 획득한 부채널 중에서 한개 이상의 부채널을 선택한다. 이것을 안정적 채널로서 보류한다. 두 번째 단계에서는 남은 부채널을 0에서부터 차례로 번호를 다시 매긴다. 서빙 기지국은 자신의 ID_cell(예를 들어, ID_cell=1)과 사용하고자 하는 안정적 부채널의 개수를

으로서 지정한 다음, 상기에서와 같이 번호가 다시 매겨진 부채널에 상기 수학식 4를 적용하여 새로운 부채널을 형성한다. 다음으로, 인접기지국은 자신의 ID_cell(예를 들어, ID_cell=2)과 사용하고자 하는 안정적 부채널의 개수를

으로서 지정한 다음, 상기에서와 같이 번호가 다시 매겨진 부채널에 상기 수학식 4를 적용하여 새로운 부채널을 형성한다. 이 때, 상기

의 값은 안정적 채널을 사용하고자 하는 단말기의 데이터를 수용할 수 있을 만큼 커야 한다. 이렇게 형성된 부채널은 서빙 셀의 기지국과, 인접 셀의 기지국에서 안정적 채널이 아닌 채널로서 사용되며, 첫 번째 단계에서 설정된 안정적 채널은 인접 기지국에서 사용되지 않아 야 하며, 서빙 기지국은 안정적 채널을 안정적 채널을 사용하고자 하는 단말기에게 할당한다. 여기서, 상기

가 '0'이면 기존의 IEEE 802.16d 통신 시스템의 부채널 할당 공식으로 돌아간다.
In other words, in the first step, the serving base station and the neighboring base station are one example, ID _cell = 0,

Equation 4 is applied while setting = 0. Thus, one or more subchannels are selected from the obtained subchannels. Hold this as a stable channel. In the second step, the remaining subchannels are renumbered in order from zero. The serving base station determines its ID _cell (eg, ID _cell = 1) and the number of stable subchannels to use.

Next, Equation 4 is applied to the subchannels renumbered as described above to form a new subchannel. Next, the neighboring base station determines its ID _cell (for example, ID _cell = 2) and the number of stable subchannels to use.

Next, Equation 4 is applied to the subchannels renumbered as described above to form a new subchannel. At this time,

The value of must be large enough to accommodate the data of the terminal to use the stable channel. The subchannel thus formed is used as a non-stable channel in the base station of the serving cell and the base station of the neighboring cell, and the stable channel set in the first step should not be used in the neighboring base station, and the serving base station is a stable channel Allocates to the terminal to use. Where

'0' returns to the subchannel allocation formula of the existing IEEE 802.16d communication system.

<Example 4>

In Embodiment 4, a new subchannel forming method for supporting a stable channel is proposed in essential requirements of an uplink PUSC subchannel allocation method. A new subchannel formation method supporting a stable channel in the essential requirements of the uplink PUSC subchannel allocation method can be obtained by applying the following formula in two steps.

는 서브 채널의 개수(예컨대, 70)를 나타낸 것이고, 상기

는 안정적 채널을 위해 필요한 부채널의 개수를 나타낸 것이고, 상기 p는 p₀에서

-1를 제외한 것을 의미한다. 여기서, 상기 p₀는 다음과 같다. Here, s denotes the number of subchannels, n denotes the number of tiles in the subchannel, and tile (n, s) denotes the number of actual tiles corresponding to the nth tile in subchannel s. To the above

Denotes the number of subchannels (eg, 70), and

Is the number of subchannels required for the stable channel, and p is at p ₀

Means except -1. Here, p ₀ is as follows.

p ₀ = {6, 48, 58, 57, 50, 1, 13, 26, 46, 44, 30, 3, 27, 53, 22, 18, 61, 7, 55, 36, 45, 37, 52, 15, 40, 2, 20, 4, 34, 31, 10, 5, 41, 9, 69, 63, 21, 11, 12, 19, 68, 56, 43, 23, 25, 39, 66, 42, 16, 47, 51,8, 62, 14, 33, 24, 32, 17, 54, 29, 67, 49, 65, 35, 38, 59, 64, 28, 60, 0}

Next, the UL _cell represents an uplink number allocated differently for each cell.

를 모두 0으로 하고 부채널에 매핑되는 부반송파들을 결정하여 FUSC 부채널을 구성한다. 그런 다음 안정적 채널을 위해 필요한

를 결정하고, 상기 결정된 값에 해당하는 부채널들을 제외한 나머지 부채널들에 부반송파들은 다시 넘버링 한다. 그런 다음 상기 UL_cell에는 각 셀 고유의 값을 대입하고, 상기

에는 상기에서 결정된 값을 대입한 후 다시 한번 부채널에 매핑되는 부반송파들을 결정하여 FUSC 부채널을 구성하게 되는 것이다.Referring to Equation 5 in more detail, cells included in the active set for the stable channel should configure the same FUSC subchannel through the same seed value. That is, the UL _cell and in the equation (4)

Set all to 0 and determine the subcarriers mapped to the subchannel to configure the FUSC subchannel. Then you need to get a stable channel

Next, the subcarriers are renumbered in the remaining subchannels except for the subchannels corresponding to the determined value. Then, a unique value of each cell is substituted into the UL _cell , and

Next, after substituting the value determined above, the subcarriers mapped to the subchannel are once again configured to configure the FUSC subchannel.

=0 으로 두고 상기 수학식 5를 적용시킨다. 그렇게 해서 얻은 부채 널 중에서 한 개 이상의 부채널을 선택한다. 이것을 안정적 채널로서 보류한다. 두 번째 단계에서는 남은 부채널을 0에서부터 차례로 번호를 다시 매긴다. 서빙 기지국은 자신의 UL_cell(예를 들어, UL_cell=1)과 사용하고자 하는 안정적 부채널의 개수를

으로서 지정한 다음, 상기에서와 같이, 번호가 다시 매겨진 부채널에 상기 수학식 5를 적용하여 새로운 부채널을 형성한다. 다음으로, 상기

의 값은 안정적 채널을 사용하고자 하는 단말기의 데이터를 수용할 수 있을 만큼 커야 한다. 인접기지국은 자신의 UL_cell(예를 들어, UL_cell=2)과 사용하고자 하는 안정적 부채널의 개수를 상기

으로서 지정한 다음, 상기에서와 같이 번호가 다시 매겨진 부채널에 상기 수학식 5를 적용하여 새로운 부채널을 형성한다. 이렇게 형성된 부채널은 서빙 셀의 기지국과, 인접 셀의 기지국에서 안정적 채널이 아닌 채널로서 사용되며, 첫 번째 단계에서 설정된 안정적 채널은 인접 기지국에서 사용되지 않아야 하며, 서빙 기지국은 안정적 채널을 안정적 채널을 사용하고자 하는 단말기에게 할당한다. 이 때, 상기

=0이면 기존의 IEEE 802.16d 통신 시스템의 부채널 할당 공식으로 돌아간다.
In other words, in the first step, the serving base station and the neighboring base station, for example, UL _cell = 0,

Equation 5 is applied while setting 0 to 0. Select one or more subchannels from the resulting debt channels. Hold this as a stable channel. In the second step, the remaining subchannels are renumbered in order from zero. The serving base station determines the number of stable subchannels to be used with its UL _cell (for example, UL _cell = 1).

Next, as shown above, a new subchannel is formed by applying Equation 5 to the renumbered subchannels. Next, above

The value of must be large enough to accommodate the data of the terminal to use the stable channel. The neighboring base station _recalls its UL _cell (for example, UL _cell = 2) and the number of stable subchannels to be used.

Next, Equation 5 is applied to the subchannels renumbered as described above to form a new subchannel. The subchannel thus formed is used as a non-stable channel in the base station of the serving cell and the neighboring cell, and the stable channel set in the first step should not be used in the neighboring base station. Assign to the terminal you want to use. At this time,

If = 0, return to the subchannel allocation formula of the existing IEEE 802.16d communication system.

<Example 5>

In Embodiment 5, a new subchannel forming method supporting a stable channel is proposed in a selection (3 × 3 tile structure) of an uplink PUSC subchannel allocation method. A new subchannel formation method that supports a stable channel in the selection of the uplink PUSC subchannel allocation method can be obtained by applying the following formula in two steps.

이다. 다음으로, 상기

는 안정적 부채널의 개수를 나타낸 것이고, 상기 s는 서브 채널 번호를 나타낸 것으로

를 나타낸다. 다음으로, 상기 m은 한 개의 서브 채널 내에서 m번 타일을 나타낸 것으로, m=0,1,2,...,5를 나타낸다. 다음으로, 상기 m'는 m'=mmodN_t-1)를 의미하고, 상기 S는 S=[s/N_t]를 의미하고, 상기 s'는 s'=smodN_t를 의미하고, 상기 c₁은 c₁=ID_cellmodN_t를 의미하고, 상기 c₂ 는 c₂ = [ID_cell/N_t]를 의미한다. 또한, 상기

는 p₁를 c₁만큼 왼쪽 cyclic shift 시킨 순열의 i번째 값을 의미하며 상기 i는 i=0,1,2,...,30 를 가진다. 또한 상기 p_2,c2[i]는 상기 p₂를 c₂ 만큼 왼쪽 cyclic shift 시킨 순열의 i번째 값을 의미하며, 상기 i는 i=0,1,2,...,30 을 가진 다. 다음으로 상기 상기 p₁은 상기

에서

를 제거시켜 얻은 순열을 나타내며, 상기 p₂는 상기

에서

를 제거시켜 얻은 순열을 나타내면, 상기 P₁ 및 P₂는 각각 하기와 같이 나타낼 수 있다.Here, N _t represents the number of tiles constituting one group (for example, 32).

to be. Next, above

Denotes the number of stable subchannels, and s denotes the subchannel number.

Indicates. Next, m represents tile m in one subchannel, and m = 0,1,2, ..., 5. Next, m 'means m' = mmodN _t -1), S means S = [s / N _t ], s 'means s' = smodN _t , c ₁ Means c ₁ = ID _cell modN _t , and c ₂ means c ₂ = [ID _cell / N _t ]. Also, the

Denotes the i th value of the permutation in which p ₁ is left cyclic shifted by c ₁ and i has i = 0,1,2, ..., 30. In addition _, p ₂ , c ₂ [i] refers to the i-th value of the permutation of the left side cyclic shifted by p ₂ by c ₂ , wherein i has i = 0,1,2, ..., 30. Next, the p ₁ is the

in

Denotes a permutation obtained by removing the p ₂ is the

in

Representing a permutation obtained by removing the, P ₁ and P ₂ can be represented as follows, respectively.

Finally, the ID _cell represents a cell ID.

를 모두 0으로 하고 부채널에 매핑되는 부반송파들을 결정하여 FUSC 부채널을 구성한다. 그런 다음 안정적 채널을 위해 필요한

를 결정하고, 상기 결정된 값에 해당하는 부채널들을 제외한 나머지 부채널들에 부반송파들은 다시 넘버링 한다. 그런 다음 상기 ID_cell에는 각 셀 고유의 값을 대입하고, 상기

에는 상기에서 결정된 값을 대입한 후 다시 한번 부채널에 매핑되는 부반송파들을 결정하여 FUSC 부채널을 구성하게 되는 것이다.Referring to Equation 6 in more detail, cells included in the active set for the stable channel should configure the same FUSC subchannel through the same seed value. That is, the ID _cell and in the equation (6)

Set all to 0 and determine the subcarriers mapped to the subchannel to configure the FUSC subchannel. Then you need to get a stable channel

Next, the subcarriers are renumbered in the remaining subchannels except for the subchannels corresponding to the determined value. Then, a unique value of each cell is substituted into the ID _cell , and the

Next, after substituting the value determined above, the subcarriers mapped to the subchannel are once again configured to configure the FUSC subchannel.

=0 으로 두고 상기 수학식 6을 적용시킨다. 그렇게 해서 얻은 부채널 중에서 한 개 이상의 부채널을 선택한다. 이것을 안정적 채널로서 보류한다. 두 번째 단계에서는 남은 부채널을 0에서부터 차례로 번호를 다시 매긴다. 서빙 기지국은 자신의 ID_cell(예를 들어, ID_cell=1)과 사용하고자 하는 안정적 부채널의 개수를

으로서 지정한 다음, 상기에서와 같이, 번호가 다시 매겨진 부채널에 상기 수학식 6을 적용하여 새로운 부채널을 형성한다.

의 값은 안정적 채널을 사용하고자 하는 단말기의 데이터를 수용할 수 있을 만큼 커야 한다. 다음으로, 인접기지국은 자신의 ID_cell(예를 들어, ID_cell=2)과 사용하고자 하는 안정적 부채널의 개수를

으로서 지정한 다음, 상기에서와 같이, 번호가 다시 매겨진 부채널에 상기 수학식 6을 적용하여 새로운 부채널을 형성한다. 이렇게 형성된 부채널은 서빙 셀의 기지국과, 인접셀의 기지국에서 안정적 채널이 아닌 채널로서 사용되며, 첫 번째 단계에서 설정된 안정적 채널은 인접 기지국에서 사용되지 않아야 하며, 서빙 기지국은 안정적 채널을 안정적 채널을 사용하고자 하는 단말기에게 할당한다.

=0이면 기존의 IEEE 802.16d 통신 시스템의 부채널 할당 공식으로 돌아간다.In the first step, the serving base station and the neighboring base station, for example, ID _cell = 0,

Equation 6 is applied while setting = 0. One or more subchannels are selected from the subchannels thus obtained. Hold this as a stable channel. In the second step, the remaining subchannels are renumbered in order from zero. The serving base station determines its ID _cell (eg, ID _cell = 1) and the number of stable subchannels to use.

Next, as shown above, a new subchannel is formed by applying Equation 6 to the renumbered subchannels.

The value of must be large enough to accommodate the data of the terminal to use the stable channel. Next, the neighboring base station determines its ID _cell (for example, ID _cell = 2) and the number of stable subchannels to use.

Next, as shown above, a new subchannel is formed by applying Equation 6 to the renumbered subchannels. The subchannel thus formed is used as a non-stable channel in the base station of the serving cell and the base station of the neighboring cell, and the stable channel set in the first step should not be used in the adjacent base station. Assign to the terminal you want to use.

If = 0, return to the subchannel allocation formula of the existing IEEE 802.16d communication system.

Next, an operation process to which Embodiments 2, 3, 4, and 5 as described above are applied will be described with reference to FIGS. 8 to 11.

FIG. 8 is a diagram schematically illustrating a FUSC subchannel allocation scheme, in which a subchannel for a stable channel is configured in the same manner for cells included in an active set as in FIG. 8 using the above equations. Some of them are allocated, and the remaining subchannels are configured to configure different FUSC subchannels for each cell. Here, FIG. 8 shows the permutation of subcarriers over two stages as described above, and also applies to the selection of downlink FUSC subchannel allocation method and uplink PUSC, which will be described later. In this case, it should be noted that permutation in the uplink means permutation of tiles, not permutations of subcarriers.

9 illustrates structures of a base station transmitter and a terminal transmitter for stable channel allocation applied to downlink FUSC and uplink PUSC to which embodiments of the present invention are applied.

Referring to FIG. 9, the modulation symbols 901 are rearranged through the first-stage permutation apparatus 902, and after the rearrangement, the stable channel separator 903 performs a stable channel (from the output of the first-stage permutation apparatus 902). 904 is separated. The remaining normal channel 905 is input to the second stage permutation device 906 with its cell number. The stable channel and the output of the two-stage permutation device are input to the IFFT unit 907.

10 illustrates structures of a base station receiver and a terminal receiver for stable channel allocation applied to a downlink FUSC and an uplink PUSC to which embodiments of the present invention are applied.

Referring to FIG. 10, the received signal passes through the FFT unit 1001, and the output of the FFT unit 1001 passes through the reverse permutation apparatus 1002 of the first stage permutation. The output of the reverse permutation apparatus 1002 of the first stage permutation is separated into the stable channel 1004 and the normal channel 1005 by the stable channel separator 1003. The normal channel is converted to the modulation &lt; RTI ID = 0.0 &gt; symbol 1008 &lt; / RTI &gt;

FIG. 11 is a diagram schematically illustrating a FUSC subchannel allocation scheme for a terminal using a stable channel in an OFDMA-TDD communication system according to the present invention.

)를 결정하고(1103), 상기 결정된 수만큼의 부채널은 안정적 채널을 원하는 단말기를 위해 예약해 둔다. 다음으로, 상기 필요한 안정적 채널을 할당한 후에는 안정적 채널을 제외한 나머지 부채널들의 부반송파들의 인덱스를 다시 넘버링 한다(1104). 상기 넘버링 수행 후, 안정적 채널에 관여하는 서빙 셀과 인접 셀은 자신의 고유 ID_cell을 이용하여 다시 넘버링 된 부반송파들을 가지고 FUSC 부채널을 구성한다(1105). 그런 다음, 상기 안정적 채널을 원하는 단말기에는 상기 (1102)의 과정을 통해 구성된 안정적 채널을 할당하고 그렇지 않은 일반적 단말기에는 상기 (1105)의 과정에서 구성된 부채널을 할당하게 된다(1106).Referring to FIG. 11, when a terminal to use a stable channel is generated (1101), the serving cell and the neighbor cell generate FUSC subchannels having the same subcarriers using the same ID _cell value (1102). After the configuration of the FUSC subchannel, the base station of the serving cell determines the number of subchannels for the stable channel based on the number of terminals to use the stable channel and the frequency usage state in the current cell.

(1103), the determined number of subchannels is reserved for a desired terminal. Next, after allocating the necessary stable channel, the indexes of subcarriers of the remaining subchannels except for the stable channel are renumbered (1104). After performing the numbering, the serving cell and the neighboring cell involved in the stable channel configure the FUSC subchannel with subcarriers renumbered using their unique ID _cells (1105). Then, the stable channel is allocated to the terminal that wants the stable channel through the process of 1102, and the subchannel configured by the process of 1105 is allocated to the general terminal that is not (1106).

를 반영하여 만들어지게 된다. In the above method, there are two permutations that configure the FUSC subchannel by mapping subcarriers to subchannels, respectively, in downlink and uplink.

It will be made to reflect.

As described above, although the detailed description of the present invention has been described by way of limited embodiments and drawings, the scope of the present invention is not limited thereto, and the scope of the present invention will be described by those skilled in the art to which the present invention pertains. Various modifications and variations are possible without departing from the spirit and scope of the appended claims.

As described above, according to the stable channel configuration method in the communication system using the orthogonal frequency division multiple access method of the present invention, in the OFDMA communication system, a stable channel implementation applied to the downlink FUSC subchannel and the uplink PUSC subchannel For this purpose, we propose a permutation formula that expresses a method of configuring uplink and downlink channels. In addition, through the above configuration, by implementing a stable channel using the subchannel configuration method and the subcarrier allocation method of the present invention, there is an advantage that can reduce the large interference caused by the neighboring cell that the conventional method can bring. In addition, through the above configuration, in a communication system using an orthogonal frequency division multiple access scheme, there is an advantage of reducing interference between cells and reliable service between terminals.

Claims (3)

A stable channel allocation method in a communication system using an orthogonal frequency division multiple access method, Generating a FUSC subchannels having the same subcarriers using the same cell identifier value when the terminal to use the stable channel is generated; After the configuration of the FUSC subchannel, determining the number of subchannels for the stable channel based on the number of terminals to use the stable channel in the serving cell and the frequency usage state in the current cell; Renumbering the indexes of subcarriers of the remaining subchannels except the stable channel after reserving the determined number of subchannels for a terminal that wants a stable channel and allocating the necessary stable channel; After performing the numbering, configuring a FUSC subchannel using subcarriers renumbered using a unique cell identifier of a serving cell and a neighboring cell involved in a stable channel; And allocating a stable channel to a terminal desiring the stable channel. The method of claim 1, The permutations constituting the FUSC subchannel by mapping the subcarriers to subchannels are provided in downlink and uplink, respectively, and each of the permutations is generated by reflecting the number of subchannels for stable channels in the existing permutations. . 2. The method of claim 1, further comprising: allocating a subchannel configured by using renumbered subcarriers except the stable channel to a terminal that does not want the stable channel.

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