KR101422578B1 - Method and apparatus for allocating resource by using inter-cell interference separation - Google Patents

Abstract

Disclosed is a resource allocation technology using inter-cell interference separation, which can increase a voice over Internet protocol (VoIP) capacity by efficiently managing VoIP resources through minimization of inter-cell interference. A method for allocating resources using the inter-cell interference separation according to the present invention, in which a base station allocates a packet of each of multiple terminals to a frequency resource in a preset cell, comprises the following steps: assigning, by the base station, an allocation priority to allocate a packet of each of multiple terminals to a frequency resource in consideration of intensity of a signal received from each of the multiple terminals and intensity of interference from a base station of an adjacent cell interfered most by the multiple terminals; defining an in-band of the frequency resource to which a preset number of packets with high allocation orders of priority among the packets are allocated; allocating the preset number of packets with high allocation orders of priority to the in-band; and allocating, in consideration of an in-band of the adjacent cell, remaining packets to an area of the frequency resource apart from the in-band of the adjacent cell.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for resource allocation using an inter-cell interference separation technique,

The present invention relates to a resource allocation method and apparatus using an intercell interference separation technique. More particularly, the present invention relates to a resource allocation method and apparatus using an inter-cell interference separation technique capable of efficiently managing Voice over Internet Protocol (VoIP) resources and minimizing VoIP capacity by minimizing inter-cell interference.

Global mobile wireless communication technology is evolving from existing WCDMA (Wideband Code Division Multiple Access) technology to LTE (Long Term Evolution) technology. The 3rd Generation Partnership Project (3GPP), a standardization body of LTE technology, adopted Voice over Internet Protocol (VoIP) technology in LTE, which is expressed as VoLTE (Voice over LTE), as a standard technology for providing voice service. However, since the VoLTE service requires QoS different from data traffic, that is, low transmission delay and packet loss rate, a suitable resource allocation scheduling method is needed.

As the demand for mobile data traffic increases rapidly, one of the strategies for accepting this tendency is to increase the overall system performance without shading area by gradually reducing the cell size. However, in such a small-sized cell, interference from surrounding cells is more important than system noise.

The characteristics of the semi-persistent scheduling scheme can be used as a multi-cell resource management scheme in a femtocell environment. In order to successfully implement cooperative scheduling scheme in multi - cell environment, it is necessary to exchange mutual information at high speed between multiple cells. However, too much overhead is required for neighboring femtocells to share the entire scheduling information used in each femtocell, and it is practically impossible to consider the backhaul delay occurring in connection characteristics of the femtocell network. However, information about resources that are periodically allocated over a long period of time is still valid even if information is exchanged after a relatively long delay. Therefore, it is possible for neighboring femtocells to share resource information that is periodically allocated. Then, it is possible to measure the average signal-to-interference-noise ratio (SINR) of each femtocell when periodically allocated resources are used, and it can be utilized for scheduling.

In this regard, Korean Patent Publication No. 10-2011-0087999 discloses a technique related to "adaptive semi-persistent scheduling method and apparatus ".

SUMMARY OF THE INVENTION It is an object of the present invention to provide a scheduling technique for reducing inter-cell interference in an uplink situation in which packets of a small size such as VoLTE are periodically formed.

It is another object of the present invention to improve VoIP capacity by managing VoIP resources efficiently by minimizing inter-cell interference.

According to another aspect of the present invention, there is provided a method of allocating resources using an inter-cell interference separation technique, the method comprising: Assigning an allocation priority assigned to a frequency resource to packets of each of the plurality of terminals; Defining, in the frequency resource, an in-band to which packets of a predetermined number of allocation priority among the packets are to be allocated; Allocating the packets having the predetermined number of allocation priority to the in-band; And allocating remaining packets in an area excluding the in-band of the adjacent cell in the frequency resource, considering the in-band of the adjacent cell.

In this case, the step of assigning the allocation priority may be performed such that the strength of a signal received from the user by the base station serving the user, and the strength of the inter-cell interference to the base station, And allocating the allocation priority assigned to the frequency resource to each of the packets using a reference ratio that is a ratio of the sum of the noise.

In this case, in the step of assigning the allocation priority, the allocation priority is calculated by using a value obtained by subtracting the number of times the packet fails to allocate the frequency resource and the number of retransmissions of the packet because the transmission fails, .

In this case, the predetermined cell is formed of a three-sector model including a first sector, a second sector and a third sector, and the frequency resource includes a first subband, a second subband, and a third subband And the step of defining the in-band may be performed such that each of the first to third sectors defines different subbands in-band.

In this case, the step of defining the in-band may include the steps of: in the first sector, the first sub-band, the second sector in the second sub-band, and the third sector in the third sub- It can be defined as a band.

At this time, in the step of defining the in-band, in the first sector, a sub-band corresponding to the number of the predetermined sector may be allocated to a packet that has the greatest interference to a predetermined sector of the neighboring cell among the residual packets Band and defining the subbands other than the in-band and the non-band as an out-band, and allocating the residual packets may allocate the residual packets to the out-band .

At this time, the step of allocating the packets having the predetermined number of allocation priorities to the in-band may allocate the packets having the predetermined number of allocation priorities from the center of the frequency band in the in-band.

At this time, the step of allocating the residual packets may allocate the residual packets from the outer part to the central part of the frequency band in the out-band.

In this case, when the resources of the out-band are exhausted, the allocation of the residual packets may allocate the residual packets from the outer part to the central part of the frequency band in the negative-band.

At this time, the step of allocating the remaining packets may include a step of allocating remaining packets to the base station by considering a first transmission for the remaining packets and a retransmission until a timeout, The residual packets may be allocated to frequency resources whose packet drop rate is less than or equal to a predetermined value.

According to another aspect of the present invention, there is provided an apparatus for allocating resources using an inter-cell interference separating method, the apparatus comprising: A priority assigning unit for assigning allocation priorities assigned to frequency resources to packets of each of the plurality of terminals in consideration of the strength; A band defining unit that defines, in the frequency resource, an in-band to which packets having a predetermined number of allocation priority among the packets are allocated; A first allocator allocating the packets having the predetermined number of allocation priorities to the in-band; And a second allocating unit for allocating residual packets in an area excluding the in-band of the neighboring cell in the frequency resource, considering the in-band of the neighboring cell.

In this case, the priority assigning unit may be configured such that the strength of the signal received from the user by the base station serving the user, and the strength of the inter-cell interference to the base station in which the user has the greatest interference, The allocation priority assigned to the frequency resource may be assigned to each of the packets using the non-reference criterion ratio.

At this time, the priority assigning unit may assign the allocation priority by using a value obtained by subtracting the number of times the packet fails to allocate the frequency resource and the number of times the packet is retransmitted due to the failure in the reference ratio .

In this case, the predetermined cell is formed of a three-sector model including a first sector, a second sector and a third sector, and the frequency resource includes a first subband, a second subband, and a third subband And the band defining unit may define different subbands in the first to third sectors as an in-band.

In this case, the band defining unit may define the first sub-band as the first sub-band, the second sector as the second sub-band, and the third sector as the in- have.

At this time, in the first sector, in the first sector, a subband corresponding to the number of the predetermined sector is defined as an exclusion-band with respect to a packet having the greatest interference to a predetermined sector of the neighboring cell among the residual packets. Band, and the second allocation unit may allocate the remaining packets to the out-band.

In this case, the first allocator may allocate packets having the predetermined number of allocation priorities from the center of the frequency band in the in-band.

At this time, the second allocator may allocate the residual packets from the outer part to the central part of the frequency band in the out-band.

In this case, if the resources of the out-band are exhausted, the second allocator may allocate the residual packets from the outer part to the central part of the frequency band in the excluded-band.

In this case, when the first transmission of the residual packet and the retransmission until the timeout are considered, the second allocating unit allocates the packet drop rate, which is a probability that transmission of the residual packet can not be successfully transmitted to the base station, The residual packet may be allocated to frequency resources whose packet drop rate is less than or equal to a predetermined value.

According to the embodiment of the present invention, it is possible to provide a scheduling technique for reducing inter-cell interference in an uplink situation in which packets of a small size such as VoLTE are periodically formed.

Accordingly, the present invention minimizes inter-cell interference, thereby effectively managing VoIP resources and improving VoIP capacity.

FIG. 1 is a diagram for explaining a semi-persistent scheduling scheme to which a resource allocation method using an inter-cell interference separation technique according to an embodiment of the present invention is applied.
2 is a flowchart illustrating a resource allocation method using an inter-cell interference separation technique according to an embodiment of the present invention.
3 is a diagram illustrating a 3-sector model to which a resource allocation method using an inter-cell interference separation technique according to an embodiment of the present invention is applied.
4 is a diagram illustrating a first application example of a resource allocation method using an inter-cell interference separation technique according to an embodiment of the present invention.
5 is a diagram illustrating a second application example of a resource allocation method using an inter-cell interference separation technique according to an embodiment of the present invention.
6 is a block diagram illustrating a resource allocation apparatus using an inter-cell interference separation technique according to an embodiment of the present invention.

The present invention will now be described in detail with reference to the accompanying drawings. Hereinafter, a repeated description, a known function that may obscure the gist of the present invention, and a detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings and the like can be exaggerated for clarity.

Hereinafter, a resource allocation method using an inter-cell interference separation technique according to an embodiment of the present invention will be described.

FIG. 1 is a diagram for explaining a semi-persistent scheduling scheme to which a resource allocation method using an inter-cell interference separation technique according to an embodiment of the present invention is applied.

Referring to FIG. 1, an anti-persistence scheduling scheme to which a resource allocation method using inter-cell interference separation scheme according to an embodiment of the present invention is applied has a problem that a channel fluctuation is very small, It is a good way to send it periodically. If the size of the packet is small, there is a large overhead of consuming the resources of the channel indicating that the resource allocation is made to the downlink in comparison with the dynamic allocation method relatively. This is because communication bottlenecks can occur due to the lack of channels that inform the resource allocation on the downlink. Also, the smaller the variation of the channel is, the better the operation is because the scheduling method operates as a persistent allocation method. This scheduling operates as follows. First, when a user sends a Scheduling Request (SR) for periodic uplink transmission to a base station, the scheduler of the base station continuously allocates the generated packets for the periodically generated user. That is, once a resource is allocated to the resource, the resource can be periodically used by the corresponding user for the uplink. In Figure 1, this is the portion indicated by Initial transmissions (persistent allocation). In this case, user 1 continues to receive the second resource on the frequency axis at a cycle of 20 ms, and the second user is also allocated to the uplink transmission at the cycle of 20 ms. It can be seen that it is used. Since the user # 3 has a scheduling request (SR) after 3ms compared to the user # 1 or # 2, it can be considered as being allocated by the scheduler after 3 ms on the time axis compared with the resource allocated by the user # 1 or # 2 If the leftmost start time is 1 ms, 4 ms, 24 ms, 44 ms, ... The resources that are repeated in the 20 ms cycle of the uplink can be used for the uplink. (Or User 3 may not have a resource that satisfies the SINR for User 3's packet even if it has done the SR at the same time as User 1, 2, or it may have been delayed from User 1, In semi-persistent allocation, packets that have not been allocated resources in persistent allocation are reallocated after 1 ms for load balancing on the time axis.)

If the persistent-allocated packet fails to be transmitted, the VoLTE retransmits after 8 ms. When retransmission fails, retransmission is performed after 8 ms. The limit of retransmission is 50 ms after the packet is generated from the user's equipment.

2 is a flowchart illustrating a resource allocation method using an inter-cell interference separation technique according to an embodiment of the present invention. The inter-cell interference separation technique according to an embodiment of the present invention relates to a technique in which a base station allocates packets of a plurality of terminals to frequency resources within a predetermined cell. Also, the resource allocation method using the inter-cell interference separation technique according to the embodiment of the present invention can be applied to the semi-persistent scheduling technique.

2, in an inter-cell interference separation technique according to an embodiment of the present invention, first, considering the strength of a signal received from a mobile station and interference strength of a neighboring cell to a base station, The allocation priority is given to the packets of the plurality of terminals when they are allocated to the frequency resources (S110).

More specifically, in step S110, the strength of the signal received from the user by the base station serving the user, and the strength of the inter-cell interference to the base station of the neighboring cell in which the user experiences the greatest interference, A non-human reference ratio is calculated, and an allocation priority assigned to the frequency resource is given to each packet using the reference ratio.

In this case, in step S110, the allocation priority may be given using a value obtained by subtracting the number of times the packet fails to allocate the frequency resource in the calculated reference ratio and the number of retransmissions of the packet because the transmission fails.

This can be expressed by the following equation (1).

The smaller the value of M (K) in Equation (1), the more the resource is allocated by the scheduler. That is, the smaller the value of M (K) is, the higher the allocation priority is. Where N _{re , k} , N _{af , k} mean the number of retransmissions and the number of failed resource allocations, respectively. As the values of N _{re , k} and N _{af, k} are larger _, the value of M (K) becomes smaller and the scheduling priority of the packet becomes higher. ω _{re , k} , and ω _{af , k} are weighting factors that determine how much weight is given to the number of retransmissions and the number of resource allocation failures in the case of packet prioritization, respectively. Also, SGINR (Signal to Generating Interference plus Noise) can be expressed by the following Equation (2).

는 사용자 k의 상향링크 전송 시 기지국이 받는 신호의 세기를 의미한다(RSS는 Received Signal Strength). 사용자 k가 상향링크 전송 시 사용자 k를 서비스하는 기지국을 제외한 다른 기지국들은 이 신호를 간섭으로 받아들이게 되는데, 사용자와 다른 기지국들과의 거리 및 각도 페이딩 등에 따라 받는 간섭의 크기가 다르게 된다. 이 때, 사용자 k가 다른 기지국들에게 미치는 간섭의 크기 중 가장 큰 값을

로 정의한다(ICI 는 Inter-cell Interference) N₀는 AWGN(Additive White Gaussian Noise)이다. 사용자 k가 생성한 패킷의 SGINR인 SGINR_K는 사용자 k를 서비스하는 기지국이 사용자 k로부터 받는 신호의 세기 대 사용자 k가 가장 큰 간섭을 미치는 기지국으로의 셀간 간섭의 세기 및 잡음의 합의 비로 정의된다. Here, k represents the index of the user,

Denotes the strength of the signal received by the base station in the uplink transmission of user k (RSS is Received Signal Strength). In the uplink transmission, the user k receives the signal as interference except for the base station servicing the user k. The size of the interference received depends on the distance between the user and other base stations, angular fading, and the like. In this case, the largest value of the interference of user k to other base stations

(ICI is Inter-cell Interference) N ₀ is Additive White Gaussian Noise (AWGN). The SGINR _{K, which} is the SGINR of the packet generated by the user k, is defined as the ratio of the strength of the signal received from the user k to the base station servicing the user k to the sum of the intensity of the intercell interference to the base station with the largest interference and the noise.

In the case of packets with the same number of retransmissions and the same number of times of failures in the persistent allocation, the SGINR is low, that is, the distance from the base station is long, so that the received signal strength received by the serving base station is small, Cell edge users that have strong interference with adjacent base stations because their distances from adjacent base stations are close to each other. In addition, if the priority is given only to the SGINR, a packet whose transmission has failed due to a bad channel once may not have a resource allocation opportunity due to packets having a lower SGINR. To compensate for this, the number of retransmissions The term to consider the number of times is added to Equation (1). When ω _{re , k} and ω _{af , k} are 0, resource allocation is performed considering only the SGINR of each user.

The effect produced when the value of? _{re , k} becomes 0 is analyzed. In the case of VoLTE, if the transmission fails for 50 ms after the packet is generated, the packet is processed as a timeout, and the packet is discarded without any further transmission opportunity. However, if the values of ω _{re , k} and ω _{af , k} are 0, the allocation priority is determined only by the SGINR. Therefore, if the SGINR is relatively large Since other packets first get good resources first by taking the opportunity of resource allocation, retransmission is likely to fail again.

The effect produced when the value of? _{af , k} becomes 0 is analyzed. If the persistent allocation fails, the VoLTE will continue to allocate the packet again after 1 ms for load balancing on the time axis. For example, It is assumed that many other packets are not allocated due to lack of resources by making a scheduling request. Then, if we try to allocate resources again after 20 ms for these failed packets, there will be a lot of packets at the previous time at t + 20n. Packets with persistent allocation failures can be considered to be packets that have been dropped in priority because the SGINR is higher than other packets. Therefore, there is a high probability that the priority is low even in other time zones, and the communication may be interrupted because it is not allocated even during the timeout period. _Given a value of ω _{af , k} greater than 0 _{, the} likelihood of receiving a higher priority each time failure of persistent allocation increases. Accordingly, it is possible to increase the capacity of the stream by supporting the uplink transmission in the network.

In step S110, an in-band to which packets with a predetermined number of allocation priority among packets are allocated in the frequency resource is defined (S120).

Then, packets having a predetermined number of allocation priorities are allocated to the in-band (S130).

After the step S130, remaining packets are allocated to an area other than the in-band of the adjacent cell in the frequency resource of the predetermined cell, considering the in-band of the adjacent cell (S140).

Steps S120 to S140 will be described in more detail. The predetermined cell may be formed of a 3-sector model including a first sector, a second sector, and a third sector, and the frequency resource may include a first subband, a second subband, and a third subband. In step S120, the first through third sectors may be defined to define different subbands as in-band. That is, in step S120, the first sector may be defined as a first subband, the second sector as a second subband, and the third sector as an in-band. In step S120, a subband corresponding to a number of a predetermined sector is defined as an exclusion-band with respect to a packet that interferes with a predetermined sector of a neighboring cell among remaining packets in the first sector, and in- Subbands other than bands can be defined as out-band. In step S140, remaining packets are allocated to the out-band.

At this time, in step S130, packets having a predetermined number of allocation priorities may be allocated from the center of the frequency band in the in-band. In step S150, remaining packets may be allocated from the outer part of the frequency band to the center part in the out-band. If the frequency resources of the out-band are exhausted in step S150, the remaining packets can be allocated from the outer part to the central part of the frequency band in the excluded-band.

In addition, in step S150, when considering retransmission until the first transmission and the timeout of the residual packet are considered, the packet drop rate, which is the probability that the transmission of the residual packet can not be successfully transmitted to the base station, The remaining packets can be allocated only to frequency resources having a predetermined value or less.

Hereinafter, an application example of the resource allocation method using the inter-cell interference separation technique according to the embodiment of the present invention will be described.

3 is a diagram illustrating a 3-sector model to which a resource allocation method using an inter-cell interference separation technique according to an embodiment of the present invention is applied. 4 is a diagram illustrating a first application example of a resource allocation method using an inter-cell interference separation technique according to an embodiment of the present invention. 5 is a diagram illustrating a second application example of a resource allocation method using an inter-cell interference separation technique according to an embodiment of the present invention.

Referring to FIG. 3, in a three-sector model in which a resource allocation method using an inter-cell interference separation technique according to an embodiment of the present invention is applied, each of the base stations A, B, C, D, , A second sector, and a third sector.

In the three-sector model, the entire sub-band is equally divided into three equal parts so that the first sub-band is the in-band of the first sector, the second sub-band is the in-band of the second sector, In-band. The out-band and the exclusion-band are changed according to a packet to which a resource is allocated. The number of subbands corresponding to the number of the in-band of the base station of the adjacent cell, Band, and the remaining subbands other than the in-band and the excluded-band are defined as out-bands. The priority of available resources is in-band highest, followed by out-band and exclusion-band. In a band of the same kind, in-band resources have a higher priority in a central resource, and other bands have a higher priority in a resource in an outer band.

More specifically, the 3-sector model of FIG. 3 shows the antenna pattern when fading is not considered. The contour line is a set in which a user receives the corresponding signal at the same power when broadcasting a downlink reference signal at the base station (the closer the base station is to the base station, the stronger the power is received from the base station). In Fig. 3, ⑨, ⑩, ⑪, and ⑫ show the position of the user, and ⑨ and ⑫ have the largest interference to the third sector of the B cell. Therefore, when the scheduler of the base station of the first sector of the predetermined cell having the A base station with the A base station allocates resources, the excluded-band will be the third sub-band. Also, the users (10) and (11) have the largest interference to the second sector of the predetermined cell having the C base station. Therefore, when the schedulers of the base stations of the first sector of a certain cell having the A base station in the A-base station are allocated resources, the excluded-band will be the second sub-band.

Considering the allocation priority of the packets together with FIG. 3, the user ⑩ is in the same contour line (the numerator value is the same in SGINR), but the user ⑨ having a larger amount of interference will have a higher priority. Users ⑪ and ⑫ will have a relatively low priority because SGINR value will be bigger compared to users ⑨ and ⑩ (the numerator value will be bigger and the denominator value will be smaller). When comparing the allocation priorities of users ⑪ and ⑫, the user ⑪ has a higher priority because the maximum interference value on the adjacent cell is similar and the user ⑫ is closer to the base station and the SGINR value is larger. Taken together, if the number of retransmissions and the number of persistent allocation failures are all the same, the allocation priority will be given in the order of users ⑨, ⑩, ⑪, and ⑫.

FIG. 4 shows an example of a technique in which a frequency resource is divided into first to third subbands, and in-band, out-band, and exclusion-band according to the present invention. The number inside the resource allocation unit indicates each user, and a smaller number indicates a user having a higher allocation priority. In particular, Fig. 4 (a) shows an example of allocating resources to packets generated by user 9 or 12 in Fig. 3, and Fig. 4 (b) This can be an example of allocating a resource to a packet generated by #n.

FIG. 5 shows which resources are allocated to the users (9), (10), (11), and (12) in FIG. At this time, the number of the user indicates the allocation priority. That is, in the case of the user 1, the desired resource can be selected from the entire resources. Since users ① to ⑧ have higher allocation priority than ⑨ and ⑩, they are packets that are at the edge of cell, have SGINR similar to users ⑨ and ⑩, or fail to continue allocation, It can be said that it is preferentially placed in the in-band. Then, it can be confirmed that the user 9 is located at the outer edge of the second subband. This is because the index of the in-band sub-band of the adjacent cell with the greatest interference of the user is 3 and the third sub-band is designated as the negative-band and the allocation priority is low. In the out-band, since the resource of the outer frame portion has the highest priority, it can be seen that the end portion resource of the outer frame portion of the second sub-band is used.

If the resource is allocated in this way, it can be seen that the first sector will have the lowest interference level in its in-band, and in particular, the centered resource will have a lower interference level. Because other base stations are basically going to fill users in the middle of the in-band of the sector first, basically, the SGINR is low (the strength of the signal received by the connected base station is weak and the maximum interference is high). And, if the in-band resources are insufficient, based on the information that each user has the greatest interference to a certain base station, the in-band of the base station avoids resources and allocates resources first. In addition, since the resource allocation starts from the both ends in the out-band, a packet having a relatively high SGINR, that is, a relatively small intensity of interference, is placed in the out-band central resource. The interference can be separated between each base station through the resource allocation method.

Since the semi-persistent scheduling scheme is used, it is relatively easy to predict how resources will be used in the future compared to the dynamic scheduling scheme. Therefore, the value of interference in the SINR (Signal to Interference plus Noise to Ratio) used when estimating whether or not to allocate resources to the resource when allocating resources is determined by interference amount of each resource before one cycle (20 ms before VoLTE) Predict. This allows a more accurate future interference prediction in the SPS.

Hereinafter, a configuration and operation of a resource allocation apparatus using an inter-cell interference separation technique according to an embodiment of the present invention will be described.

6 is a block diagram illustrating a resource allocation apparatus using an inter-cell interference separation technique according to an embodiment of the present invention.

Referring to FIG. 6, a resource allocation apparatus 100 using an inter-cell interference separation technique according to an embodiment of the present invention includes a priority assignment unit 110, a band definition unit 120, a first allocation unit 130, And a second allocation unit 140. [ The resource allocation apparatus using the inter-cell interference separation technique according to an embodiment of the present invention relates to a technique in which a base station allocates packets of a plurality of terminals to frequency resources in a predetermined cell. The resource allocation apparatus using the inter-cell interference separation scheme according to the embodiment of the present invention can be applied to the semi-persistent scheduling scheme. In this case, the predetermined cell is formed of a three-sector model including a first sector, a second sector and a third sector, and a frequency resource allocated by the base station includes a first subband, a second subband, And the like.

The priority assigning unit 110 assigns a frequency resource to each of the plurality of terminals in consideration of the strength of a signal received from each terminal and the intensity of interference to a base station of a neighboring cell, And assigns an allocation priority assigned to each of them.

In this case, the priority assigning unit 110 determines whether the strength of the signal received from the user by the base station serving the user, the strength of the inter-cell interference to the base station in which the user has the greatest interference, Using the non-human reference ratio, each packet may be assigned an allocation priority assigned to a frequency resource. More specifically, the priority assigning unit 110 may assign an allocation priority to the reference ratio using a value obtained by subtracting the number of times the packet fails to allocate the frequency resource and the number of retransmissions of the packet because the transmission fails. have.

The band defining unit 120 defines an in-band to which packets having a predetermined number of allocation priority among the packets are allocated in the frequency resource. The band defining unit 120 defines different subbands in each of the first to third sectors of a predetermined cell as an in-band. In addition, the band defining unit 120 may define the first subband as the first sector, the second subband as the second sector, and the third subband as the in-band. In this case, the band defining unit 120 defines a subband corresponding to the number of the predetermined sector as a negative-band with respect to a packet that has the greatest interference to a predetermined sector of a neighboring cell among remaining packets in the first sector, The in-band and the non-band-defined subbands are defined as out-band.

The first allocator 130 allocates the packets having the predetermined number of allocation priorities to the in-band. In this case, the first allocator 130 may allocate a predetermined number of packets having a higher priority from the center of the frequency band in the in-band. The first allocator 130 may allocate a predetermined number of packets having a higher priority from the center of the frequency band in the in-band.

The second allocating unit 140 allocates remaining packets in an area excluding the in-band of the adjacent cell in the frequency resource, considering the in-band of the adjacent cell. At this time, the second allocator 140 may allocate the remaining packets to the out-band. The second allocator 140 may allocate the residual packets from the outer part to the central part of the frequency band in the out-band. In addition, when the resources of the out-band are exhausted, the second allocator 140 may allocate the residual packets from the outer part to the central part of the frequency band in the exclusion-band. In addition, when considering the first transmission for a residual packet and the retransmission until a time-out, the second allocator 140 determines whether a packet drop rate (Packet), which is a probability that the transmission of the residual packet can not be successfully transmitted to the base station the drop rate may be allocated to frequency resources less than or equal to a predetermined value.

As described above, the resource allocation method and apparatus using the inter-cell interference separation technique according to the present invention are not limited to the configuration and method of the embodiments described above, but the embodiments can be variously modified All or some of the embodiments may be selectively combined.

100; Resource allocation device
110; Priority availability
120; Band definition section
130; The first assigning unit
140; The second allocation unit

Claims (20)

1. A resource allocation method for allocating packets of a plurality of terminals to a frequency resource by a base station in a predetermined cell,
Considering the strength of a signal received from each of the UEs and the strength of an interference to a Node B of a neighboring cell in which the UE experiences the greatest interference, an allocation priority assigned to a frequency resource for each of the plurality of UEs Ranking;
Defining, in the frequency resource, an in-band to which a predetermined number of packets with a higher allocation priority than the other packets are to be allocated;
Allocating a predetermined number of packets having higher allocation priority than other packets among the packets to the in-band; And
And allocating remaining packets in an area other than the in-band of the neighboring cell in the frequency resource considering the in-band of the neighboring cell.
The method according to claim 1,
Wherein the step of assigning the allocation priority comprises:
Using a reference ratio, which is a ratio of the strength of a signal received from the user to the base station serving the user to the intensity of the inter-cell interference to the base station in which the user has the greatest interference and the sum of the noise, And assigning the allocation priority assigned to the frequency resource to the packets. The method of claim 2,
Wherein the step of assigning the allocation priority comprises:
Wherein the allocation priority is given using a value obtained by subtracting the number of times the packet fails to allocate the frequency resource and the number of retransmissions of the packet due to the failure in transmission at the reference ratio. Assignment method. The method according to claim 1,
Wherein the predetermined cell is formed of a three-sector model including a first sector, a second sector and a third sector, the frequency resource including a first subband, a second subband, and a third subband,
The step of defining the in-
Wherein each of the first to third sectors is configured to define different subbands as an in-band. The method of claim 4,
The step of defining the in-
Wherein the first sector defines the first subband, the second sector defines the second subband, and the third sector defines the third subband as an in-band. Resource allocation method. The method of claim 5,
The step of defining the in-
In the first sector, a subband corresponding to a number of the predetermined sector is defined as an exclusion-band with respect to a packet having the greatest interference to a predetermined sector of the neighboring cell among the residual packets, and the in- Excluding sub-bands are defined as out-bands,
The step of allocating residual packets comprises:
And allocating the residual packet to the out-band. The method of claim 6,
Wherein the step of allocating a predetermined number of packets having a higher allocation priority than the other packets among the packets to the in-
And allocating the packets having the predetermined number of allocation priorities from the center of the frequency band in the in-band.
The method of claim 6,
The step of allocating residual packets comprises:
And allocating the residual packets from the outer part to the central part of the frequency band in the out-band. The method of claim 8,
The step of allocating residual packets comprises:
And allocating the remaining packets from the outer part to the central part of the frequency band in the excluded-band when resources of the out-band are exhausted. The method according to claim 1,
The step of allocating residual packets comprises:
The packet drop rate, which is a probability that the transmission of the residual packet can not be successfully transmitted to the base station, is considered when considering the retransmission until the first transmission and the timeout of the remaining packet are considered. And allocating the residual packets to frequency resources having a value equal to or less than a predetermined value. A resource allocation apparatus in which a base station allocates packets of a plurality of terminals to a frequency resource in a predetermined cell,
Considering the strength of a signal received from each terminal and the intensity of interference to a base station of a neighboring cell in which the terminal experiences the greatest interference, an allocation priority assigned to a frequency resource for each of the plurality of terminals A priority order granting a priority;
A band defining unit for defining, in the frequency resource, an in-band to which a predetermined number of packets with a higher allocation priority than the other packets are allocated;
A first allocator allocating a predetermined number of packets having a higher allocation priority than other packets among the packets to the in-band; And
And a second allocator for allocating residual packets in an area excluding the in-band of the neighboring cell in the frequency resource considering the in-band of the neighboring cell. Device.
The method of claim 11,
Wherein the priority-
Using a reference ratio, which is a ratio of the strength of a signal received from the user to the base station serving the user to the intensity of the inter-cell interference to the base station in which the user has the greatest interference and the sum of the noise, And allocates the allocation priority assigned to the frequency resource to the packets. The method of claim 12,
Wherein the priority-
Wherein the allocation priority is given using a value obtained by subtracting the number of times the packet fails to allocate the frequency resource and the number of retransmissions of the packet due to the failure in transmission at the reference ratio. Allocation device. The method of claim 11,
The predetermined cell is formed of a three-sector model including a first sector, a second sector, and a third sector, and the frequency resource includes a first subband, a second subband, and a third subband ,
The band defining unit may include:
Wherein different subbands are defined as in-bands in each of the first to third sectors. 15. The method of claim 14,
The band defining unit may include:
Wherein the first sector defines the first subband, the second sector defines the second subband, and the third sector defines the third subband as an in-band. Resource allocation apparatus using resource allocation. 16. The method of claim 15,
The band defining unit may include:
In the first sector, a subband corresponding to a number of the predetermined sector is defined as an exclusion-band with respect to a packet having the greatest interference to a predetermined sector of the neighboring cell among the residual packets, and the in- Excluding sub-bands are defined as out-bands,
Wherein the second allocating unit allocates,
And allocating the remaining packets to the out-band. 18. The method of claim 16,
Wherein the first allocating unit allocates,
Wherein a predetermined number of packets having a higher allocation priority than other packets among the packets are allocated from the center of the frequency band in the in-band.
18. The method of claim 16,
Wherein the second allocating unit allocates,
And allocating the residual packets from the outer part to the central part of the frequency band in the out-band. 19. The method of claim 18,
Wherein the second allocating unit allocates,
And allocating the remaining packets from the outer part to the central part of the frequency band in the excluded-band when resources of the out-band are exhausted. The method of claim 11,
Wherein the second allocating unit allocates,
The packet drop rate, which is a probability that the transmission of the residual packet can not be successfully transmitted to the base station, is considered when considering the retransmission until the first transmission and the timeout of the remaining packet are considered. Wherein the remaining packets are allocated to frequency resources having a value equal to or less than a predetermined value.

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