WO2011085514A1

WO2011085514A1 - Method and equipment for inter-cell interference coordination in relay-assisted cellular system

Info

Publication number: WO2011085514A1
Application number: PCT/CN2010/000055
Authority: WO
Inventors: 庞继勇; 王栋耀; 刘建国; 沈钢
Original assignee: 上海贝尔股份有限公司; 阿尔卡特朗讯
Priority date: 2010-01-13
Filing date: 2010-01-13
Publication date: 2011-07-21
Also published as: CN102668659A; CN102668659B

Abstract

A method for inter-cell interference coordination (ICIC) in a relay-assisted network is provided in the present invention, and in the relay-assisted network, user equipments (UE) are divided into macro UEs which are directly serviced by base stations, and relay UEs which are indirectly serviced by the base stations through relay nodes. The method includes the following steps: calculating the mean percentage of relay UEs, wherein the mean percentage of relay UEs is the mean percentage of the number of relay UEs serviced by a single relay node in the cell to the total number of UEs; according to the calculated mean percentage of relay UEs, determining the system bandwidth to be distributed to the relay nodes, and distributing the rest system bandwidth to the base station; and determining the further scheduling of the relay nodes and base station to the distributed system bandwidth based on the scheduling algorithm. An equipment for inter-cell interference coordination ICIC in the relay-assisted network is also provided in the present invention.

Description

Method and apparatus for inter-cell interference coordination in a relay-assisted cellular system

Technical field

The present invention relates to interference coordination methods and apparatus in a cellular system, and more particularly to a method and apparatus for inter-cell interference coordination in a relay assisted cellular network. Background technique

Orthogonal Frequency Division Multiple Access (OFDMA) has been accepted by 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) as a promising downlink air interface technology for next generation systems (see S. Sesia, I. Toufik) And M. Baker, "LTE - the UMTS long term evolution: from theory to practice," Wiley Press, 2009, incorporated herein by reference. OFDMA provides inherent flexibility for radio resource allocation and avoiding intra-cell interference. However, strong inter-cell interference caused by dense resource multiplexing limits the possibility of making full use of the OFDMA scheme. Therefore, to reduce inter-cell interference, it is necessary to provide suitable radio resource management (RRM).

Currently, the following three techniques for reducing inter-cell interference (ICIM) are mainly considered: 1) interference randomization, 2) interference cancellation, and 3) interference coordination (see M. Rahman, H. Yanikomeroglu, and W. Wong, "Interference avoidance With dynamic inter-cell coordination for downlink LTE system, "Proc. IEEE WCNC 09, April 2009, incorporated herein by reference. However, interference randomization does not substantially reduce interference, and interference cancellation can only eliminate primary interference, so interference coordination that limits downlink resource management in a coordinated manner to achieve optimal network performance is considered 3GPP LTE. The most promising ICIM approach.

A large number of available Inter-Cell Interference Coordination (ICIC) techniques are based on the Fractional Frequency Multiplexing (FFR) principle shown in Figure 1. FFR considers multiplexing division, in which a cell edge user equipment (UE) is allocated a resource (a part of spectrum) having a higher multiplexing factor than a cell center UE, and a resource (entire frequency band or a part of spectrum) allocated to a cell center UE is only The limited power of low power transmitted by the enhanced Node B (eNB) to the cell edge UE is multiplexed. However, based on various considerations (especially downlink power control may confuse downlink channel quality indicator (CQI) measurements, thus affecting the effectiveness of downlink adaptation and scheduling), ultimately the data channel in LTE Downlink power control is not supported on top, which makes FFR ineffective or meaningless for ICIC.

Recently, multi-hop relay technology has been widely discussed in LTE and LTE-A, and it has been introduced into 3GPP. Version 9 and higher (see 3GPP TR 36.814, "Further Advancements for E-UTRA Physical Layer Aspects," vl.2.1, June 2009, incorporated herein by reference). In a relay assistance system, each UE may actively or passively access an eNB or a relay node (RN). By deploying the RN at the cell edge, the cell edge UE can experience increased received signal power from the serving RN. In this way, FFR is available in LTE without reducing the _e NB transmission power at the cell center frequency resource. The present invention has been completed based on the above considerations. Summary of the invention

In order to solve the problems in the prior art, the present invention proposes a method and apparatus for performing inter-cell interference coordination ICIC in a relay assisted network.

According to an aspect of the present invention, there is provided a method of performing inter-cell interference coordination ICIC in a relay assistance network, in which a user equipment UE is divided into macro UEs directly served by a base station and via The relay node is indirectly relayed by the base station, and the method includes the following steps: calculating an average relay UE ratio, wherein the average relay UE ratio is a number of relay UEs served by a single relay node in the cell. Average percentage of the number of all UEs; determining the system bandwidth to be allocated to the relay node based on the calculated average relay UE ratio, and allocating the remaining system bandwidth to the base station; and determining the relay node and the base station based on the scheduling algorithm Further scheduling of the allocated system bandwidth.

Preferably, the scheduling algorithm is an enhanced proportional fair scheduling algorithm that relies on a buffer queue state factor. The system bandwidth allocated to the relay node and the system bandwidth allocated to the base station are mutually orthogonal.

The step of determining further scheduling includes: calculating, according to a first enhanced proportional fair scheduling algorithm, a first scheduling criterion for the relay node, to determine a scheduling priority that further allocates the allocated system bandwidth to the relaying UE. Scheduling Algorithm,

Where t denotes a time index, ^··· ' ^(ί ) denotes an instantaneous supportable data rate of the relay UE m, denotes an exponentially filtered average service rate of the relay UE m for a certain time constant τ, and i _£ ,. (0 represents the expected buffer rate of the relay UE m.

The step of determining further scheduling further includes: calculating a second scheduling criterion for the base station based on the second enhanced proportional fair scheduling algorithm to determine to further allocate the allocated system bandwidth to the macro UE and the relay backhaul link. Scheduling Algorithm,

Where t represents the time index, (t) represents the instantaneous supportable data rate of the macro UE n, (t) represents the exponentially filtered average service rate of the macro UE n for a certain time constant τ, and R) represents the relay The average rate of the backhaul link corresponding to UE m, and _ρ (0 represents the improved backhaul link rate considering the state of the relay buffer queue) - the method further includes, according to the current UE association scheme and traffic load information, Determine if the UE is a relay UE or a macro UE.

According to another aspect of the present invention, there is provided an apparatus for performing inter-cell interference coordination ICIC in a relay assistance network, in which a user equipment UE is divided into macro UEs directly served by a base station and via The relay node is indirectly relayed by the base station, and the device includes: a computing device, configured to calculate an average relay UE ratio, where the average relay UE ratio is a relay served by a single relay node in the cell The number of UEs is an average percentage of the number of all UEs; the allocating means is configured to determine a system bandwidth to be allocated to the relay node according to the calculated average relay UE ratio, and allocate the remaining system bandwidth to the base station; and a scheduling device, A method for determining further scheduling of the allocated system bandwidth by the relay node and the base station based on the scheduling algorithm.

Preferably, the scheduling algorithm is an enhanced proportional fair scheduling algorithm that relies on a buffer queue state factor. The system bandwidth allocated to the relay node and the system bandwidth allocated to the base station are mutually orthogonal. The scheduling apparatus includes: a first scheduling apparatus, configured to calculate, according to a first enhanced proportional fair scheduling algorithm, a first scheduling criterion for a relay node, to determine a scheduling priority for further allocating the allocated system bandwidth to the relay UE level. The first enhanced proportional fair scheduling algorithm is implemented by the following formula,

Where t represents the time index, ^'W represents the instantaneous supportable data rate of the relay UE m, represents the exponentially filtered average service rate of the relay UE m for a certain time constant, and, (0 represents the relay UE m Expected buffer rate.

The scheduling apparatus further includes: a second scheduling apparatus, configured to calculate a second scheduling criterion for the base station based on the second enhanced proportional fair scheduling algorithm, to determine to further allocate the allocated system bandwidth to the macro UE and to implement the relay back Second enhanced proportional fair scheduling algorithm,

Where t represents a time index, indicating that the instantaneous UE can support the data rate, JO represents the exponentially filtered average service rate of the macro UE n for a certain time constant τ, and represents the average rate of the path corresponding to the relay UE m And ^(0 represents an improved backhaul link considering the state of the relay buffer queue. The device further includes determining means for determining the current UE association scheme and traffic load information, Whether the UE is a relay UE or a macro UE.

The present invention is directed to a LTE downlink transmission in a relay-assisted cellular network, and proposes a new FFR-based ICIC scheme that utilizes a corresponding enhanced PFS algorithm. In the FFR model, the entire system bandwidth is divided into two orthogonal parts, one for macro UEs served directly by the eNB and the other for relay UEs served by the cell edge RN. The resources used to relay the UE may be multiplexed by all RNs because the RN has limited transmission power; similarly, resources for macro UEs may also be multiplexed by all eNBs because these resources are for cell center UEs. This spectral division does not require power control at the eNB, but is very easy to implement. The semi-static adjustment is performed by determining the number of relay UEs according to the current UE association and traffic load, and then determining the amount of relay UE resources according to the calculated average relay UE ratio. At the same time, in order to fully utilize the FFR model, an enhanced PFS that considers the state of the relay buffer in the scheduling priority criterion is proposed to provide an equalization method for resource usage. The present invention can significantly improve the system performance of a cellular system in which a relay node is deployed. DRAWINGS

The above and other aspects, features, and advantages of the present invention will become more apparent from the detailed description of the appended claims.

FIG. 1 illustrates a typical FFR configuration in accordance with an exemplary embodiment of the present invention;

2 shows a schematic diagram of relay assisted transmission in accordance with an exemplary embodiment of the present invention;

3 is a block diagram showing the structure of an inter-cell interference coordination apparatus according to an exemplary embodiment of the present invention; FIG. 4 is a flowchart showing an inter-cell interference coordination method according to an exemplary embodiment of the present invention; The layout of the multi-cell hexagon of the exemplary embodiment of the present invention and the corresponding spectrum division;

FIG. 6 illustrates an LTE FDD downlink frame structure in accordance with an exemplary embodiment of the present invention; FIG.

FIG. 7 illustrates a semi-static resource allocation in accordance with an exemplary embodiment of the present invention;

Figure 8 illustrates the throughput gain of an FRR based ICIC scheme in accordance with an illustrative embodiment of the present invention. detailed description .

Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings. In this illustrative embodiment, an LTE system is taken as an example. However, those skilled in the art should understand that the scope of the present invention is not limited thereto, and the exemplary embodiments are only for the purpose of description, and should be considered as an example of the invention, and no limitation of the invention, The solutions of the embodiments are all within the scope of the invention. The present invention proposes a new fractional frequency reuse FFR scheme for inter-cell interference coordination ICIC in a relay-assisted cellular network. The basic idea of the present invention is to avoid intra-cell and inter-cell interference from an eNB to an RN through semi-static orthogonal resource allocation based on a relay UE association ratio and dynamic resource scheduling via an enhanced proportional fair scheduling (PFS) algorithm. , which includes the following main points:

(1) deploying a relay node at the edge of the cell;

(2) classifying all UEs in each cell into two categories: UEs directly accessed and served by the eNB are referred to as macro UEs; and UEs indirectly served by the eNB via RNs are referred to as relay UEs;

(3) dividing the entire system spectrum into two orthogonal sub-bands, such as Fe and Fr, where Fe is allocated to the eNB, and the eNB finally allocates the macro UE and the relay backhaul link using the PFS; and Fr It is allocated to the RN accordingly, and is finally allocated by the RN to the relay UE using the PFS. Such division ensures that there is no interference between the eNB and the RN;

(4) All cells in the network follow the same spectrum partitioning, i.e., Fe can be multiplexed by all donor eNBs, and Fr can be multiplexed by all RNs. Since Fe is used for cell center UEs, it is expected that the interference power from neighboring eNBs is much smaller than the signal power from the donor eNB. At the same time, it can also be assumed that the inter-cell RN interference is within an acceptable range because R has a very limited coverage (the transmission power of the RN is much lower than the transmission power of the eNB);

(5) The width of Fr is proportional to the average relay UE ratio, and is adjusted in a semi-static manner to match the current network state;

(6) The average relay UE ratio is the average percentage of the number of relayed UEs served by a single RN to the average number of UEs in a single cell. Specifically, the total number of relayed UEs in the whole network is divided by the total number of UEs in the whole network. The total number of RNs in the whole network. Since each cell may have a different total number of UEs, it may also contain a different number of RNs, and each RN may also serve a different number of relay UEs. In order to calculate the average relay UE ratio, the number of relay UEs is reported from each lower RN to the donor eNB via the Un interface; on the other hand, the number of relay UEs is exchanged between different eNBs through the X2 interface. It should be understood by those skilled in the art that the Un interface is an interface between the Rn and the eNB; and the X2 interface is an interface between the eNB and the eNB;

(7) In order to make full use of the FFR scheme, resource allocation is based on the Enhanced PF Scheduling (PFS) algorithm. This enhancement is achieved by introducing the factors of the buffer queue state into the scheduling criteria, thereby achieving a more suitable resource allocation.

Referring to FIG. 3, FIG. 3 is a block diagram showing the structure of an inter-cell interference coordination apparatus 300 according to an exemplary embodiment of the present invention. As shown in FIG. 3, the inter-cell interference coordination device 300 includes: a computing device 301, configured to calculate an average a relaying UE ratio, wherein the average relaying UE ratio is an average percentage of the number of relaying UEs served by a single RN in the cell, and an allocation device 303, configured to calculate, according to the calculated average relaying UE ratio, Determining the system bandwidth to be allocated to the RN and allocating the remaining system bandwidth to the eNB; scheduling means 305 for determining further scheduling of the allocated system bandwidth by the RN and the eNB based on the enhanced proportional fair scheduling algorithm.

The scheduling apparatus 305 includes: a first scheduling apparatus (not shown) for calculating a first scheduling result at the RN based on the first enhanced PFS algorithm to determine a schedule for further allocating the allocated system bandwidth to the relaying UE a second scheduling device (not shown) for calculating a second scheduling result at the eNB based on the second enhanced PFS algorithm to determine to further allocate the allocated system bandwidth to the macro UE and the relay backhaul chain The scheduling priority of the path, wherein the first and second enhanced PFS algorithms are dependent on a buffer queue state factor.

Moreover, the inter-cell interference coordination device 300 can also include a determining device disposed prior to the computing device 301.

(not shown), configured to determine, according to the current UE association scheme and traffic load information, whether the UE is a relay UE or a macro UE, so as to determine the number of relay UEs.

An inter-cell interference coordination method according to an exemplary embodiment of the present invention will be described below with reference to FIG. 4-7. In the exemplary embodiment, an LTE FDD downlink transmission is taken as an example. It will be appreciated that the invention is not limited thereto but may be applied to other wireless fields.

Fig. 5 schematically shows the layout of a multi-cell hexagon and the corresponding spectral division. As shown in Figure 5, it can be deployed at the edge of each cell, for example, two RNs. Taking the LTE FDD system as an example, each downlink frame in the LTE FDD system is typically 10 ms long, including 20 time slots of 0.5 ms in length, labeled 0-19, as shown in FIG. 6. A subframe is defined as two consecutive time slots, where subframe i includes time slots 2i and 2i+1.

In the case of a 10 MHz system bandwidth, there are a total of 50 physical resource blocks (PRBs) in each subframe. It is assumed that an average of 25 UEs are evenly distributed in each cell, and are served by one of the eNBs or RNs according to the currently suitable UE association scheme (for example, considering maximum received signal power, or shortest distance, etc.) and actual traffic load. . As mentioned before, a UE that is directly served by an eNB is called a macro UE, and a UE that is indirectly served by an eNB through an RN is called a relay UE.

In step 401, the determining apparatus determines whether the UE is a relay UE or a macro UE according to the current UE association scheme and traffic load information, so as to determine the number of relay UEs.

Then, each RN reports the number of relay UEs to the eNB through the Un interface, and exchanges the UE association information (that is, the number of relay UEs) in different eNBs through the X2 interface.

In step S403, the average relay UE ratio is calculated by the computing device 301.

In step S405, the allocating means 303 determines to allocate to the RN based on the calculated average relay UE ratio. System bandwidth, and allocate the remaining system bandwidth to the eNB.

For example, assume that, for a specific duration, on average, each RN indirectly serves 3 UEs, gp, relay UEs (thus knowing that the average relay UE ratio is 3/25=12%), and the donor eNB directly Serves 19 UEs. Therefore, the entire system bandwidth can be divided into the following two parts according to the average relay UE ratio of 12%: Fr, 1-6 PRBs; and Fe, 7-50 PRBs, BP, which allocates the first 12% of resources to The RN serves to relay the UE, and allocates the remaining resources to the eNB to serve the macro UE and the relay backhaul link, as shown in FIG.

Since the resource scheduling algorithm greatly affects the performance of the FFR, the present invention proposes an enhanced PFS, which is obtained by introducing factors related to the buffer queue state in the scheduling criteria, thereby achieving a more suitable resource allocation.

In step S407, the scheduling device 305 determines further scheduling of the Fr and Fe allocated by the RN and the eNB for the allocation device 303 based on the enhanced PFS algorithm.

Specifically, in step S407, the first scheduling result at the RN is calculated by the first scheduling device based on the first enhanced PFS algorithm to determine a scheduling priority for further allocating the allocated system bandwidth to the relay UE. The second scheduling device calculates a second scheduling result at the eNB based on the second enhanced PFS algorithm to determine a scheduling priority for further allocating the allocated system bandwidth to the macro UE and the relay backhaul link. among them,

1) Implement the first enhancement PFS algorithm as shown in the following expression (1) one (3) gives:

For the RN PFS of each PRB in the Fr band, the scheduling priority criterion is

M _r {t) - arg max ϊ ) where t is the time index, 7C (0 is the instantaneous supportable data rate of the relay UE m, and is a relay UE for a certain time constant r updated according to the following formula Exponential filtering average service rate of m

f (1 - T)R' _wi . (t) + T - min , (t), R _B "„' _FFER {t)} , if ^(,) = , "

(l- r)C( , if M )≠'"

. And ^ (0 is the expected buffer rate of the relay UE m, defined as:

_R! „ _ UE _OT buffer queue total length (in bits) _{( 3 )} buffer ) TTI where TTI is equal to lms, ie, the transmission time interval of one subframe. Through the newly arrived data queue length and service RN The retransmission data queue length at both ends to determine the total length of the buffer queue. Compared with the prior art PFS algorithm M (0 = _ar gm _max ^^, the proposed scheduling priority criterion considers the UE The buffer state, thereby avoiding scheduling the UE with an empty buffer.

2) Implement the second enhanced PFS algorithm as given by the following expressions (4) and (5) - Assuming that the traffic loading model at the eNB is an infmitely-backlogged model, also referred to as a full load model, for each eNB PFS at the RPB of the Fe band, in each time step, the scheduling priority criterion is

Where t denotes a time index indicating that the instantaneous UE can support the data rate, (0 represents the exponentially filtered average service rate of the macro UE n for a certain time constant τ, 4 _r (t) denotes the relay UE m The average rate of the corresponding backhaul link, and / ^ (0 represents the modified backhaul link rate considering the relay buffer queue state. The calculation of the PF priority of the macro UE n is Hf, lR _a ⁿ _v fy And the average rate of the backhaul link corresponding to the relay UE m (4(0) is the same as in the prior art. However, for the relay backhaul link corresponding to the relay UE m/,, R ^ (o denotes an improved backhaul link rate that takes into account the queue status of the relay buffer:

0, if the link queue length of link / _m is greater than a certain threshold si

R _p (t) = +∞, if the buffer of the link / is empty, and the total RN buffer queue length is less than a certain threshold S2 ( 5 )

R;), other situations

Among them, (0 is the backhaul link /, „ instantaneous support channel rate.

By using R (0 instead of ^, (0, the relay backhaul link does not consume too much Fe-band resources, and can simultaneously provide a balanced data stream to the relay UE. Thus, it can be in the macro UE and the relay backhaul chain The Fe band is more appropriately used in the road.

Thus, combining semi-static resource allocation with enhanced PFS can effectively implement FFR-based ICIC in a relay-assisted cellular network without limiting power control at the eNB.

The present invention is directed to a LTE downlink transmission in a relay-assisted cellular network, and proposes a new FFR-based ICIC scheme that utilizes a corresponding enhanced PFS algorithm. In the FFR model, the entire system bandwidth is divided into two orthogonal parts, one for macro UEs served directly by the eNB and the other for relay UEs served by the cell edge RN. The resources used to relay the UE may be multiplexed by all RNs because the RN has limited transmission power. Similarly, resources for macro UEs can also be multiplexed by all eNBs because these resources are for cell center UEs. This spectral division does not require power control at the eNB, but is very easy to implement. The semi-static adjustment is performed by determining the number of relay UEs according to the current UE association and traffic load, and then determining the amount of relay UE resources according to the calculated average relay UE ratio. At the same time, in order to fully utilize the FFR model, an enhanced PFS that considers the state of the relay buffer in the scheduling priority criterion is proposed to provide an equalization method for resource usage.

In addition, the proposed method can be used for Type I and Type II relay nodes, which is very advantageous for applications in the 3GPP LTE-A standard.

The FFR-based ICIC scheme according to the present invention can provide in terms of cell average and cell edge spectral efficiency For better system performance.

Figure 8 shows a schematic diagram of the significant performance gain (normalized user throughput) of the proposed method. Table 1 below records the corresponding cell average and cell edge (5%) user throughput gains for each of the cases in Figure 8 (the throughput has been normalized in Table 1). After calculation, it can be known that by using RN multiplexing, there are 9.4% and 4.0% increase in cell average and cell edge throughput respectively; by using orthogonal RN transmission in each cell, in cell average and cell edge There was an increase of 3.0% and 16.0% in throughput, respectively.

Table 1

Table 2 below gives the parameters used in the simulation of the wireless cellular system using the method and apparatus of the present invention.

Table 2

Table 2. System level simulation parameters As can be seen from the data given above, the present invention can significantly improve the system performance of a cellular system in which a relay node is deployed. The solution according to the invention has the following characteristics -

- the eNB and its subordinate R use orthogonal frequency resources;

- performing resource allocation within the cell in a semi-static manner;

- reporting UE association information from the RN to the donor eNB through the Un interface;

- Different eNBs interact with each other to exchange their respective UE association results and the like through the X2 interface. The present invention mainly relates to an FFR-based ICIC solution that satisfies the 3GPP LTE relay definition and thus can be implemented directly based on existing technologies.

Those skilled in the art will readily recognize that the various steps of the above methods can be implemented by programming using a computer. Herein, some embodiments also include a machine readable or computer readable program storage device (eg, a digital data storage medium) and encoding machine executable or computer executable program instructions, wherein the instructions perform some of the above methods or All steps. For example, the program storage device can be a digital memory, a magnetic storage medium (such as a magnetic disk and magnetic tape), a hardware or an optically readable digital data storage medium. Embodiments also include a computer that executes a program recorded on a storage medium to perform the steps of the above method. The descriptions of the above and the drawings are merely illustrative for the purpose of illustrating the invention. It will be appreciated by those skilled in the art that the present invention may be practiced in various embodiments, and the various structures are not described or illustrated herein. Within the scope. Furthermore, all of the examples mentioned herein are explicitly used primarily for teaching purposes to assist the reader in understanding the principles of the invention and the concepts promoted by the inventors, and should be construed as not The limitations of the examples and conditions. In addition, all statements herein reciting principles, aspects, and embodiments of the invention, as well as the specific examples thereof,

Claims

Rights request

A method for performing inter-cell interference coordination ICIC in a relay assistance network, in which a user equipment UE is divided into a macro UE directly served by a base station and indirectly served by a base station via a relay node Relay UE, the method includes the following steps:

Calculating an average relay UE ratio, wherein the average relay UE ratio is an average percentage of the number of relay UEs served by a single relay node in the cell, and the average percentage of all UEs;

Determining a system bandwidth to be allocated to the relay node based on the calculated average relay UE ratio, and allocating the remaining system bandwidth to the base station;

Further scheduling of the allocated system bandwidth by the relay node and the base station is determined based on a scheduling algorithm.

2. The method of claim 1, wherein the scheduling algorithm is an enhanced proportional fair scheduling algorithm that relies on buffer queue state factors.

3. The method of claim 1, wherein the system bandwidth allocated to the relay node and the system bandwidth allocated to the base station are mutually orthogonal.

4. The method of claim 2, wherein the step of determining further scheduling comprises:

A first scheduling criterion for the relay node is calculated based on the first enhanced proportional fair scheduling algorithm to determine a scheduling priority for further allocating the allocated system bandwidth to the relaying UE.

The first enhanced proportional fair scheduling algorithm is implemented by the following formula.

Where t denotes a time index, ( ^(ί) denotes the instantaneous supportable data rate of the relay UE m, ⁰ denotes the exponentially filtered average service rate of the relay UE m for a certain time constant f, and 73⁄4^,. Indicates the expected buffer rate of the relay UE m.

6. The method of claim 2, wherein the determining the further scheduling further comprises: calculating a second scheduling criterion for the base station based on the second enhanced proportional fair scheduling algorithm to determine to further allocate the allocated system bandwidth to the macro The scheduling priority of the UE and the relay backhaul link.

, wherein the second enhanced proportional fair scheduling algorithm is implemented by the following formula,

Where t denotes the time index, ?^(t) denotes the instantaneous supportable data rate of the macro UE n, and (t) denotes the exponentially filtered average service rate of the macro UE n for a certain time constant r, _r (0 means The average rate of the backhaul link corresponding to UE m, and / 3⁄4 _p (0 represents an improved backhaul link considering the state of the relay buffer queue)

8. The method according to claim 1, further comprising determining whether the UE is a relay UE or a macro UE according to a current UE association scheme and traffic load information.

9. A device for inter-cell interference coordination ICIC in a relay assisted network, in which the user equipment UE is divided into macro UEs directly served by the base station and indirectly served by the base station via the relay node Relaying the UE, the device includes:

a computing device, configured to calculate an average relay UE ratio, where the average relay UE ratio is an average percentage of the number of relay UEs served by a single relay node in the cell, and the average percentage of all UEs;

And a means for determining, according to the calculated average relay UE ratio, determining a system bandwidth to be allocated to the relay node, and allocating the remaining system bandwidth to the base station;

And a scheduling apparatus, configured to determine, according to a scheduling algorithm, further scheduling of the allocated system bandwidth by the relay node and the base station.

10. The apparatus of claim 9, wherein the scheduling algorithm is an enhanced proportional fair scheduling algorithm that relies on a buffer queue state factor.

11. The apparatus of claim 9, wherein the system bandwidth allocated to the relay node and the system bandwidth allocated to the base station are mutually orthogonal.

12. The device of claim 10, wherein the scheduling device comprises:

And a first scheduling apparatus, configured to calculate a first scheduling criterion for the relay node based on the first enhanced proportional fair scheduling algorithm to determine a scheduling priority for further allocating the allocated system bandwidth to the relay UE.

13. The apparatus according to claim 12, wherein the first enhanced proportional fair scheduling algorithm is implemented by:

Where t denotes a time index, denotes an instantaneous supportable data rate of the relay UE m, denotes an exponentially filtered average service rate of the relay UE m for a certain time constant, and /3⁄4, (0 denotes the expectation of the relay UE m Buffer rate.

14. The apparatus according to claim 10, wherein the scheduling apparatus further comprises: second scheduling means, configured to calculate a second scheduling criterion for the base station based on the second enhanced proportional fair scheduling algorithm to determine the allocated The system bandwidth is further allocated to the scheduling priorities of the macro UE and the relay backhaul link.

15. The apparatus according to claim 14, wherein the second enhanced proportional fair scheduling algorithm is implemented by:

Where t represents the time index, i) represents the instantaneous supportable data rate of the macro UEn, 2 (0 represents the exponentially filtered average service rate of the macro UE n for a certain time constant, and R (t) represents the relay UE m The average rate of the corresponding backhaul link, and the improved backhaul link rate that takes into account the state of the relay buffer queue.

The device according to claim 9, further comprising: determining means, determining, according to the current UE association scheme and traffic load information, whether the UE is a relay UE or a macro UE.