WO2013143101A1

WO2013143101A1 - Methods and apparatuses for resource allocation

Info

Publication number: WO2013143101A1
Application number: PCT/CN2012/073239
Authority: WO
Inventors: Lei Jiang; Ming Lei
Original assignee: Nec (China) Co., Ltd.
Priority date: 2012-03-29
Filing date: 2012-03-29
Publication date: 2013-10-03
Also published as: CN103814613A; CN103814613B

Abstract

Provided are methods and corresponding apparatuses for resource allocation. A method comprises calculating a respective marginal benefit difference for each of a plurality of user equipments according to an initial almost blank subframe pattern; sorting the plurality of UEs in an order based upon the initial almost blank pattern; and partitioning the user equipments into unique partitions; determining one partition that maximizes a utility function; repeatedly performing previous steps until a maximal utility function is identified; and arranging the user equipment according to the partition corresponding to the maximal utility function. With the claimed inventions, interference from a macro base station could be ameliorated and the spectrum efficiency would be enhanced due to improved resource allocation.

Description

METHODS AND APPARATUSES FOR RESOURCE ALLOCATION

FIELD OF THE INVENTION [0001] Embodiments of the present invention generally relate to wireless communication techniques including the 3 GPP (the 3rd Generation Partnership Project) LTE (Long Term Evolution) technique. More particularly, embodiments of the present invention relate to methods and apparatuses for resource allocation. BACKGROUND OF THE INVENTION

[0002] Various abbreviations that appear in the specification and/or in the drawing figures are defined as below:

ABS Almost Blank Subframe

CRE Cell Range Extension

elCIC enhanced Inter-Cell Interference Coordination

eNB evolved Node B

FDD Frequency Division Duplex

KKT Karush-Kuhn-Tucher

LPN Low Power Node

LTE Long Term Evolution

LTE-A LTE-Advanced

NBS Nash Bargaining Solution

NSF Normal SubFrame

PSF Protected SubFrame

PF Proportional Fairness

RRH Remote Radio Head

TDD Time Division Duplex

UE User equipment

[0003] LTE and LTE-A techniques have become the next generation cellular communication standards. In an LTE-A system, a heterogeneous network is generally deployed with LPNs, which may include but are not limited to a pico eNB, a femto eNB, a relay node, and an RRH. These LPNs may increase the spectrum efficiency and improve the system coverage. However, they may be subject to some interference which does not exist in a conventional homogeneous network. One of the interfering scenarios is that transmissions of a macro eNB (a.k.a an interfering eNB, which acts as an aggressor in the interference) may interfere with those of the UEs served by an LPN (a.k.a a protected eNB in an elCIC field), which acts as a victim in the interference and needs to be protected), especially when a CRE technique is applied.

[0004] To alleviate such kind of interference, an elCIC scheme has been employed in which the macro eNB will transmit with zero or non-zero low power in the ABSs and the interfered UEs as covered by the LPNs would be arranged to transmit data in PSFs that correspond to the ABSs, thereby avoiding the interference from the macro eNB. The number of ABSs is one of crucial factors in determining the system throughput and scheduling UEs by the protected eNBs on these PSFs may also affect the system throughput. Thus, how to form a reasonable and feasible ABS pattern and which UEs should be scheduled or arranged in the PSFs should be considered comprehensively. The existing techniques intend to address both problems separately and thus it is less likely to significantly improve the system throughput.

[0005] Bi view of the above, it would be desirable to alleviate or even eliminate the above interference and achieve better spectrum efficiency in wireless communication.

SUMMARY OF THE INVENTION [0006] Therefore, there is a need in the art to provide for an efficient way of resource allocation such that the interference as discussed above could be suppressed together with better spectrum efficiency.

[0007] In an exemplary embodiment of the present invention, a method for resource allocation is provided, which comprises:

[0008] a) sorting a plurality of UEs in an order according to respective marginal benefit difference of each of the plurality of UEs, wherein the respective marginal benefit difference indicates difference between the marginal benefit obtained if the UE is arranged in a NSF and the marginal benefit obtained if the UE is arranged in a PSF according to an ABS pattern;

[0009] b) repeatedly partitioning the plurality of sorted UEs to form a plurality of unique partitions, each unique partition consisting of one or more successive UEs in the order that are to be arranged in NSFs and correspondingly remaining one or more successive UEs in the order that are to be arranged in PSFs;

[0010] c) calculating a utility function for each of the plurality of unique partitions to determine one of the plurality of unique partitions that maximizes the utility function;

[0011] d) recording a result of the maximized utility function;

[0012] e) using the determined partition to update the respective marginal benefit difference;

[0013] f) repeatedly performing steps a)-e) with the updated respective marginal benefit difference until the result of the currently recorded maximized utility function is less than that of the immediately previously recorded maximized utility function; and

[0014] g) arranging, according to the partition which corresponds to the immediately previously maximized utility function, each of the plurality of UEs in the NSF or the PSF.

[0015] In one embodiment, the method further comprises receiving the ABS pattern from an external entity.

[0016] In another embodiment, the method further comprises:

[0017] calculating a first amount of data transmitted by a protected BS if a time period of an ABS configuration is completely occupied by the NSFs;

[0018] calculating a second amount of data transmitted by the protected BS if the time period of the ABS configuration is completely occupied by the ABSs;

[0019] sending information regarding the first and second amounts of data to the external entity for updating the ABS pattern; and

[0020] stopping sending the information upon receipt of a stopping instruction from the external entity.

[0021] In an additional embodiment, the respective marginal benefit difference is calculated by subtracting the marginal benefit obtained if the UE is arranged in the PSF from the marginal benefit obtained if the UE is arranged in the NSF.

[0022] In a further embodiment, the sorting the plurality of UEs in the order comprises sorting the plurality of UEs in a descending order, and the each partition comprises one or more successive UEs in the descending order that are to be arranged in the NSFs and correspondingly remaining one or more successive UEs in the descending order that are to be arranged in the PSFs.

[0023] In yet another embodiment, the sorting the plurality of UEs in the order comprises sorting the plurality of UEs in an ascending order, and the each partition comprises one or more successive UEs in the ascending order that are to be arranged in the PSFs and correspondingly remaining one or more successive UEs that are to be arranged in the NSFs.

[0024] In a further embodiment, the respective marginal benefit difference is calculated by subtracting the marginal benefit obtained if the UE is arranged in the NSF from the marginal benefit obtained if the UE is arranged in the PSF.

[0025] In one embodiment, the sorting the plurality of UEs in the order comprises sorting the plurality of UEs in a descending order, and the each partition comprises one or more successive UEs in the descending order that are to be arranged in the PSFs and correspondingly remaining one or more successive UEs in the descending order that are to be arranged in the NSFs.

[0026] In another embodiment, the sorting the plurality of UEs in the order comprises sorting the plurality of UEs in an ascending order, and the each partition comprises one or more successive UEs in the ascending order that are to be arranged in the NSFs and correspondingly remaining one or more successive UEs that are to be arranged in the PSFs.

[0027] In another exemplary embodiment of the present invention, a method for resource allocation is provided, which comprises:

[0028] receiving, from one or more BSs, information regarding at least one of a first amount of data if a time period of an ABS configuration is completely occupied by NSFs and a second amount of data if the time period of the ABS configuration is completely occupied by ABSs;

[0029] forming, based upon the information, a respective utility function of each of the one or more BSs; and

[0030] determining an ABS pattern which maximizes a result of a joint utility function, wherein the joint utility function is obtained by operations on all the respective utility functions of the one or more BSs.

[0031] In one embodiment, the BS is a protected BS and the information relate to the first and second amounts of data.

[0032] In an additional embodiment, the BS is an interfering BS and the information relates to the first amount of data.

[0033] In a further embodiment, the method further comprises updating the ABS pattern based upon newly received information regarding the amount of data or based upon an event; and

[0034] sending the updated ABS pattern to the one or more BSs.

[0035] In yet another embodiment, the method further comprises instructing the one or more BSs not to send the information when the updated ABS pattern has been converged.

[0036] In an additional exemplary embodiment of the present invention, an apparatus for resource allocation is provided, which comprises:

[0037] a) means for sorting a plurality of UEs in an order according to respective marginal benefit difference of each of the plurality of UEs, wherein the respective marginal benefit difference indicates difference between the marginal benefit obtained if the UE is arranged in a NSF and the marginal benefit obtained if the UE is arranged in a PSF according to an ABS pattern;

[0038] b) means for repeatedly partitioning the plurality of sorted UEs to form a plurality of unique partitions, each unique partition consisting of one or more successive UEs in the order that are to be arranged in NSFs and correspondingly remaining one or more successive UEs in the order that are to be arranged in PSFs;

[0039] c) means for calculating a utility function for each of the plurality of unique partitions to determine one of the plurality of unique partitions that maximizes the utility function;

[0040] d) means for recording a result of the maximized utility function;

[0041] e) means for using the determined partition to update the respective marginal benefit difference;

[0042] f) means for instructing means a)-e) to repeatedly perform with the updated respective marginal benefit difference until the result of the currently recorded maximized utility function is less than that of the immediately previously recorded maximized utility function; and

[0043] g) means for arranging, according to the partition which corresponds to the immediately previously maximized utility function, each of the plurality of UEs in the NSF or the PSF.

[0044] In a further exemplary embodiment of the present invention, an apparatus for resource allocation is provided, which comprises:

[0045] means for receiving, from one or more BSs, information regarding at least one of a first amount of data if a time period of an ABS configuration is completely occupied by NSFs and a second amount of data if the time period of the ABS configuration is completely occupied by ABSs;

[0046] means for forming, based upon the information, a respective utility function of each of the one or more BSs; and

[0047] means for determining an ABS pattern which maximizes a result of a joint utility function, wherein the joint utility function is obtained by operations on all the respective utility functions of the one or more BSs.

[0048] In one exemplary embodiment of the present invention, an apparatus for resource allocation is provided, which comprises at least one processor and at least one memory including computer program code. The memory and the computer program code are configured to cause the apparatus at least to:

[0049] a) sort a plurality of UEs in an order according to respective marginal benefit difference of each of the plurality of UEs, wherein the respective marginal benefit difference indicates difference between the marginal benefit obtained if the UE is arranged in a NSF and the marginal benefit obtained if the UE is arranged in a PSF according to an ABS pattern;

[0050] b) repeatedly partition the plurality of sorted UEs to form a plurality of unique partitions, each unique partition consisting of one or more successive UEs in the order that are to be arranged in NSFs and correspondingly remaining one or more successive UEs in the order that are to be arranged in PSFs;

[0051] c) calculate a utility function for each of the plurality of unique partitions to determine one of the plurality of unique partitions that maximizes the utility function;

[0052] d) record a result of the maximized utility function;

[0053] e) use the determined partition to update the respective marginal benefit difference;

[0054] f) repeatedly perform steps a)-e) with the updated respective marginal benefit difference until the result of the currently recorded maximized utility function is less than that of the immediately previously recorded maximized utility function; and

[0055] g) arrange, according to the partition which corresponds to the immediately previously maximized utility function, each of the plurality of UEs in the NSF or the PSF.

[0056] In another exemplary embodiment of the present invention, an apparatus for resource allocation is provided, which comprises at least one processor and at least one memory including computer program code. The memory and the computer program code are configured to cause the apparatus at least to:

[0057] receive, from one or more BSs, information regarding at least one of a first amount of data if a time period of an ABS configuration is completely occupied by NSFs and a second amount of data if the time period of the ABS configuration is completely occupied by

ABSs;

[0058] form, based upon the information, a respective utility function of each of the one or more BSs; and

[0059] determine an ABS pattern which maximizes a result of a joint utility function, wherein the joint utility function is obtained by operations on all the respective utility functions of the one or more BSs.

[0060] According to certain embodiments of the present invention, by proper resource allocation, the interference as discussed previously would be avoided effectively. Further, because the ABS pattern can be dynamically updated according to the amount of data, resource as characterized by subframes can be allocated reasonably among the UEs and thereby the system throughput can be ameliorated and enhanced.

[0061] Other features and advantages of the embodiments of the present invention will also be understood from the following description of specific embodiments when read in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The embodiments of the invention that are presented in the sense of examples and their advantages are explained in greater detail below with reference to the accompanying drawings, in which:

[0063] Fig. 1 is a diagram exemplarily illustrating an ABS configuration reflecting an ABS pattern in which a plurality of UEs connected with the protected BSs would be arranged in NSFs or PSFs accordingly.

[0064] Fig. 2 is a flow chart schematically illustrating a method for resource allocation at e.g., an LPN (i.e., a protected BS) according to an embodiment of the present invention;

[0065] Fig. 3 is a flow chart schematically illustrating a method for resource allocation at e.g., a marco eNB (i.e., an interfering BS) with an internal center controller or at an external center controller according to an embodiment of the present invention;

[0066] Fig. 4 is a block diagram schematically illustrating a method for resource allocation according to an embodiment of the present invention;

[0067] Fig. 5 is a flow chart schematically illustrating a method for resource allocation according to another embodiment of the present invention;

[0068] Fig. 6 is a flow chart schematically illustrating a method for resource allocation according to an embodiment of the present invention; and

[0069] Fig. 7 is a schematic block diagram of a BS and a UE that are suitable for use in practicing the exemplary embodiments of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0070] While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention.

[0071] To facilitate the understanding of this invention, a number of terms are defined below. Terms defined herein have meanings as commonly understood by a person of ordinary skill in the areas relevant to the present invention. Terms such as "a," "an" and "the" are not intended to refer to only a singular entity, but include the general class of which a specific example may be used for illustration. The terminology herein is used to describe specific embodiments of the invention, but their usage does not delimit the invention. For example, a BS in the present invention may refer to one of a NB, an eNB, a base transceiver station, a radio BS, and the like and thus they may be used interchangeably throughout the specification and claims as appropriate,

[0072] Embodiments of the present invention propose an efficient mechanism of scheduling UEs in the protected BSs and allocating proper time resources to the interfering BSs and the protected BSs. By virtue of a constantly updated ABS pattern generated in consideration of amounts of data transmitted by one or more protected or interfering BSs during a time period of an ABS configuration, UEs that are served by the protected BSs would be appropriately scheduled in PSFs and NSFs for transmission. Due to different scheduling, the protected or the interfering BSs may transmit new amounts of data which could be used for adjusting and updating the previous ABS pattern. In this manner, the interference from the interfering BSs to the UEs served by the protected BSs could be eliminated while the system throughput and spectrum efficiency would be improved.

[0073] Embodiments of the present invention will be described in connection with the drawings in detail as below.

[0074] Fig. 1 is a diagram exemplarily illustrating an ABS configuration reflecting an ABS pattern in which a plurality of UEs connected with the protected BSs would be arranged in NSFs and PSFs accordingly, for a better understanding of the present invention. As illustrated in Fig.l, each subframe is exemplarily shown as a block and different kinds of subframes are distinguished from each other with different filled content. In particular, blocks representing the ABSs are filled with blank space; blocks representing the NSFs are filled with oblique lines; blocks representing the PSFs are filled with intersection lines. Also illustrated is a time axis upon which two series of subframes are arranged. The upper series of subframes demonstrate an ABS pattern arranged at an interfering BS and the lower series of subframes demonstrate the same ABS pattern received at a protected BS from the interfering BS. It can be noted from Fig. 1 that an ABS at the interfering BS corresponds to a PSF at the protected BS. A time period of an ABS configuration as constituted by these series of subframes is denoted by a single curly brace with an English letter "T." Prior to scheduling one or more UEs, the protected BS may receive from the interfering BS an ABS pattern based upon which the protected BS may arrange some UEs in the PSFs corresponding to the ABSs and arrange other UEs in the NSFs such that potential interference from the interfering BS may be avoided.

[0075] It should be noted that the ABS configuration as illustrated above takes an FDD system frame structure as an example and the number of the subframes during the time period of the ABS configuration is shown only for illustrative purposes. A person skilled in the art would be aware that a similar ABS configuration also exists in a TDD system with a different frame structure to which an elCIC technique may also be applied. In addition, based upon the ABS pattern, a parameter β which denotes a ratio of a number of ABSs to a total number of subframes in a time period of an ABS configuration (i.e., a time interval as noted above by "T") can be calculated and used for determining marginal benefit difference, as will be discussed in detail later.

[0076] Fig. 2 is a flow chart schematically illustrating a method 200 for resource allocation at e.g., an LPN (i.e., a protected BS) according to an embodiment of the present invention. As illustrated in Fig. 2, the method 200 starts at step S201 and proceeds to step S202 at which the method 200 sorts a plurality of UEs including potentially protected UEs in an order according to respective marginal benefit difference of each of the plurality of UEs, wherein the respective marginal benefit difference indicates difference between the marginal benefit obtained if the UE is arranged in a NSF and the marginal benefit obtained if the UE is arranged in a PSF according to an ABS pattern. In some embodiments, the marginal benefit difference could be obtained by constructing a mathematical function in which specific partitions of the plurality of UEs and a predetermined or constantly updated parameter β may be used as arguments and calculating the result of the mathematical function.

[0077] Subsequent to the sorting, the method 200 proceeds to step S203, at which the method 200 repeatedly partitions the plurality of sorted UEs to form a plurality of unique partitions, wherein each unique partition consists of one or more successive UEs in the order that are to be arranged in NSFs and correspondingly remaining one or more successive UEs in the order that are to be arranged in PSFs. For example, there are n UEs within the coverage of the protected (or interfered) BS. Then, the first partition may consist of the first UE in the order that is to be arranged in the NSF and the remaining n-\ successive UEs that are to be arranged in the PSFs and second partition may consist of the first two UEs in the order that are to be arranged in the NSFs and the remaining UEs from the third to the last one that are to be arranged in the PSFs and so on until the last partition may consist of the first n-l UEs that are to be arranged in the NSFs and the last one that is to be arranged in the PSF.

[0078] Following repeatedly partition of the plurality of UEs, the method 200 advances to step S204, at which the method 200 calculates a utility function for each of the plurality of unique partitions to determine one of the plurality of unique partitions that maximizes the utility function. Then at step S205, the method 200 records a result of the maximized utility function and at step S206, uses the determined partition to update the respective marginal benefit difference.

[0079] All things being equal, the method 200 repeatedly performs step S202 to S206 with the updated respective marginal benefit difference until the result of the currently recorded maximized utility function is less than that of the immediately previously recorded maximized utility function. Then the method 200 arranges, at step S208, according to the partition which corresponds to the immediately previously maximized utility function, each of the plurality of UEs in the NSF or the PSF. Finally, the method 200 ends at step S209.

[0080] Although not illustrated in Fig. 2, in some embodiments, the method 200 further receives the ABS pattern from an external entity, e.g., a center controller located within an interfering BS or a remote center controller. In some embodiments, the method 200 calculates a first amount of data transmitted by a protected BS if a time period of an ABS configuration is completely occupied by the NSFs and calculates a second amount of data transmitted by the protected BS if the time period of the ABS configuration is completely occupied by the ABSs (i.e., subframes corresponding to PSFs). Then, the method 200 sends information regarding the first and second amounts of data to the external entity for updating the ABS partem based upon which the β can be calculated. In some embodiments, if the value of the β has been converged and could be kept unchanged for a certain amount of time at the external entity, then the method 200 stops sending the information upon receipt of a stopping instruction from the external entity.

[0081] hi some embodiments, the respective marginal benefit difference is calculated by subtracting the marginal benefit obtained if the UE is arranged in the PSF from the marginal benefit obtained if the UE is arranged in the NSF. In this case, the sorting the plurality of UEs in the order comprises sorting the plurality of UEs in a descending or ascending order. If the plurality of UEs are sorted in the descending order, then the each partition comprises one or more successive UEs that are to be arranged in the NSFs and correspondingly remaining one or more successive UEs that are to be arranged in the PSFs. In contrast, if the plurality of UEs are sorted in the ascending order, then the each partition comprises one or more successive UEs that are to be arranged in the PSFs and correspondingly remaining one or more successive UEs that are to be arranged in the NSFs.

[0082] In some embodiments, the respective marginal benefit difference is calculated by subtracting the marginal benefit obtained if the UE is arranged in the NSF from the marginal benefit obtained if the UE is arranged in the PSF. In this case, the sorting the plurality of UEs in the order comprises sorting the plurality of UEs in a descending or ascending order. If the plurality of UEs are sorted in the descending order, then the each partition comprises one or more successive UEs that are to be arranged in the PSFs and correspondingly remaining one or more successive UEs that are to be arranged in the NSFs. In contrast, if the plurality of UEs are sorted in the ascending order, then the each partition comprises one or more successive UEs that are to be arranged in the NSFs and correspondingly remaining one or more successive UEs that are to be arranged in the PSFs.

[0083] The foregoing has discussed the method 200 and its variants according to certain embodiments of the present invention. A person skilled in the art, based upon the description and teachings herein, would be aware that one reasonable and valid partition could be determined and uncovered from the plurality of unique partitions on the condition that it maximizes the utility function. Consequently, arranging the plurality of UEs according to the determined partition would decrease the interference from the interfering BS and improve the spectrum efficiency.

[0084] Fig. 3 is a flow chart schematically illustrating a method 300 for resource allocation at e.g., a marco eNB (i.e., an interfering BS) with an internal center controller or at an external center controller according to an embodiment of the present invention. As illustrated in Fig. 3, the method 300 starts at step S301 and proceeds to step S302, at which the method 300 receives, from one or more BSs, information regarding at least one of a first amount of data if a time period of an ABS configuration is completely occupied by NSFs and a second amount of data if the time period of the ABS configuration is completely occupied by ABSs.

[0085] Upon receipt of the information, the method 300 proceeds to step S303, at which the method 300 forms, based upon the information, a respective utility function of each of the one or more BSs. Following forming the respective utility function, the method 300 determines, at step S304, an ABS pattern which maximizes a result of a joint utility function, wherein the joint utility function is obtained by operations on all the respective utility functions of the one or more BSs. In some embodiments, the operations may include but not are limited to continued multiplication or addition of the respective utility functions. Finally, the method 300 ends at step S305.

[0086] Although not illustrated in Fig. 3, in some embodiments, the BS is a protected BS and the information relate to the first and second amounts of data. In yet some embodiments, the BS is an interfering BS and the information relates to the first amount of data. In other words, since the interfering BS only schedules or arrange its own served UEs in the NSFs, it is unlikely to provide the information about the second amounts of the data.

[0087] In some embodiments, over time, the method 300 updates the ABS pattern based upon newly received information regarding the amount of data or based upon an event, and sends the updated ABS pattern to the one or more BSs. In some embodiments, the updating can be performed in a predetermined period of time or in an event-triggered manner. The event could be for example an occurrence of a handover procedure.

[0088] In some embodiments, the method 300 instructs the one or more BSs not to send the information when the updated ABS pattern has been converged. By temporarily instructing the protected or other interfering BSs not to send the information, the signaling overhead and costs in this regard could be saved.

[0089] Fig. 4 is a block diagram schematically illustrating a method 400 for resource allocation according to an embodiment of the present invention. As illustrated in Fig. 4, the method 400 begins at step S401, at which a protected eNB (or BS) partitions, according to an ABS pattern, a plurality of UEs which are likely to be interfered by an interfering eNB (or BS). The ABS pattern has been received from the interfering eNB (or a center controller therein or remote therefrom), as shown by a left arrow towards the protected eNB. Upon partitioning the UEs, the method 400 proceeds to step S402, at which the protected eNB schedules these UEs according to the partition at issue. It can be noted that the steps S401 and S402 could be generalized from the steps S202 to S208 as illustrated in Fig. 2.

[0090] Subsequent to scheduling the UEs according to the partition, i.e., arranging the UEs in the NSFs and PSFs accordingly, the protected eNB may send the information regarding a first and second amounts of data to the interfering eNB for updating the ABS pattern, as shown by a right arrow towards the interfering eNB, wherein the first amount of data is assumed to be transmitted by the protected BS if a time period of an ABS configuration is completely occupied by the NSFs and the second amount of data is assumed to be transmitted by the protected BS if the time period of the ABS configuration is completely occupied by the ABSs. Upon receipt of the information regarding the amount of data from one or more protected eNB or other interfering eNBs (only one is shown), the method 400 initiates an ABS updating procedure at step S403, wherein a new ABS pattern may be obtained by constituting a joint utility function for all eNBs and determining the new ABS pattern that maximizes the joint utility function, as previously discussed in the method 300 in connection with Fig. 3. Once the new ABS pattern has been generated, it could be delivered to the protected and other interfering eNBs for updating the partition. As to the interfering eNB itself, it would arrange, at step S404, its served UEs in the NSFs and leave ABSs for use by the interfered BSs. By this "close-loop" manner, problems regarding how to schedule the UEs and how to select an appropriate ABS pattern could be very-well solved and such scheduling and selecting actions can be perfectly coordinated, which gives the system throughput a big boost.

[0091] Fig. 5 is a flow chart schematically illustrating a method 500 for resource allocation according to another embodiment of the present invention. As illustrated in Fig. 5, the method 500 starts at step S501 and advances to step S502, at which a first variable k is initially set with a value of zero. At step S503, the method 500 arranges UEs of a protected eNB in a descending order according to a respective marginal benefit difference. Below are details of the respective marginal benefit difference.

[0092] First, according to exemplary embodiments of the present invention, the UE partitions as previously discussed can be modeled as a NBS wherein the NSFs and PSFs compete for the plurality of UEs and each UE has a likelihood of being allocated in NSFs or

2 ,

PSFs, i.e.,∑£2.. = 1 , where ay indicates that UE in the plurality of UEs is allocated in a subframe of type /. Suppose that i^'=l indicates a NSF and i=2 indicates a PSF, if the * UE is not arranged in the NSF, then

Likewise, if the j^th UE is not arranged in the PSF, then a_2j= , and if the ' UE is arranged in the

½i 2

PSF, then a₂j=h It is apparent that ∑ ∑ a„ = N _PUE , where the N_PUE indicates NUEs that are j=l f=l

currently attached to the protected BS.

[0093] Based upon the above variable a,_j, then a utility function can be defined as below:

*/ = n i=l w -J ⁾

where R denotes an amount of data when a protected BS transmits in the NSFs and R₂ denotes an amount of data when the protected BS transmits in the PSFs during a time period of the ABS configuration, and where )Γ(1 -β) = R (1 - β) (2)

W

R, = a_2J log₂ (1 + SINR_m>psf )Tfi = 1ζ"β , (3)

2j

[0094] where R" denotes an amount of data transmitted by the protected BS if the time period of the ABS configuration is completely occupied by the NSFs, R° denotes an amount of data transmitted by the protected BS if the time period of the ABS configuration is completely occupied by the ABSs, R_{l n} denotes a minimal amount of data (or minimal performance) at an initial agreement point with respect to the NSF, and R_{2 min} denotes a minimal amount of data at an initial agreement point with respect to the PSF. For simplicity, ^ι,πώ ^2,min ^can be ^set *° ^zero> which results in a PF case.

[0095] By relaxing ay to be 0 < a_i7< 1 and applying a Lagrangian multiplier λ_} , a Lagrangian function can be established as below:

[0097] By conducting the steps of using a KKT condition, taking the derivative of the above function with respect to letting the resulting mathematical expression equal to zero, and solving the equation, the below equation is given:

[0098] Take the difference of the left side and the right side of the above equation, the below equation is given:

[0099] where N_\ denotes a number of the UEs arranged in the NSFs, Λ¾ denotes a number of the UEs arranged in the PSFs_; a j = +SINR_WB,nsfj, where the SINR_WB,„_s/_j denotes a signal-to-interference plus noise ratio of the f^h UE in the NSF; c¾

where the

SINRwB,p_Sfj denotes a signal-to-interference plus noise ratio of the f^h UE in the PSF;

W(l - 8) ^N WB

Pi = _τ ^■ «iy - ^ι Ά = ~ log_{2 2J} - R_{2 n} , where β denotes a ratio of a number of ABSs to a total number of subframes in a time period of an ABS configuration, W denotes bandwidth.

[0100] It should be known from the above that the function is used

to calculate the marginal benefit difference by subtraction of the marginal benefit obtained if the * UE is allocated in the PSF from the one obtained if the * UE is allocated in the NSF. When

>0, the j UE should be arranged in a NSF; otherwise, it should be arranged in a

PSF. In addition, the item β , as discussed before, can be preset or obtained based upon an

ABS pattern from an external entity, e.g., a center controller or an interfering BS as illustrated in Fig. 4 or discussed later in Fig. 6.

[0101] Returning to the Fig. 5, upon using the equation (6) to calculate the respective marginal benefit difference of each UE and sorting the UEs in a descending order, the method 500 proceeds to step S504, at which a second variable j is initially set with a value of zero. After that, the method 500 advances to step S505, at which the method 500 conducts the following steps until the updated value of the j is equal to NPUE-1 :

[0102] (1) let j=j+l ;

[0103] (2) arrange 1 to j UEs on the NSFs;

[0104] (3) arrange j+1 to N_PUE on the PSFs; and

[0105] (4) calculate the utility function U(j) as expressed in the equation (1).

[0106] It can be seen that repetitive performance of the above substeps (1) and (3) would partition the UEs into a plurality of unique partitions as discussed previously in connection with the Fig. 1.

[0107] Once the respective utility function for each of the plurality of unique partitions has been calculated, the method 500 proceeds to step S507, at which one partition J that maximizes the utility function would be determined, as illustrated by "J= ar max {U(j)} ," j

and let k=k+l and record the U(J) by the equation "U_max(k)=U(J)." The method 500 then proceeds to step S508, at which a condition "k>l&& Umax(k) < U_max(k-1)" is judged. If the condition is false, then the method 500 would repeat the steps S503 to S508 with the updated parameters, that is, update the respective marginal benefit difference with new items ρ_λ ,ρ₂ , Ν_\, and N₂ changed due to the determined partition J and conduct a next round of step S504 to S508. If the condition is true, then the method 500 proceeds to step S509, at which the method 500 arranges the UEs in the NSFs and the rest of UEs in the ABSs according to the final J that corresponds to the U_max(k- 1 ). Finally, the method 500 ends at step S510.

[0108] Additionally, subsequent to arranging the UEs in the corresponding NSFs and

PSFS, the method 500 calculates the Rf and Rf as included in the equations (2) and (3) and delivers, via e.g., a signaling message, the information regarding the R" and Rf to the center controller or the interfering BS as illustrated in Fig. 4 and discussed later in Fig. 6.

[0109] The foregoing has discussed, in connection with Fig. 5, the method 500 which may involve further implemental details or variants of the methods 200-400; however, the present invention is not limited thereto. For example, although the above functions e.g., the specific function specific

expressions, the present invention is not limited thereto and they may take different expressions. For the utility function U, it may also be expressed as below:

[0111] Accordingly, R_\ and i?₂ maybe expressed as below:

W "g

[0112] N "PWUEE f ^E a_Xj log. (1 + SINR_minsf . )T(l - β) = Rf (1 - β) (8)

Σ «1

[0113] R> _i log₂(l + SINR_WBiPsf )Tfi = R₂ ^a"fi (9)

Upon the above alternatives, a function similar in nature to the

[0116] on the condition that the previous equations (4) and (5) are substituted with the equations as below:

[0118] In addition, the descending order as shown in Fig. 5 is also only illustrative and the UEs can be sorted flexibly according to the manner in which the marginal benefit difference is calculated. For example, in the method 500, the marginal benefit difference is derived by subtraction of the marginal benefit obtained if the UE is

allocated in the PSF from the one obtained if the ' UE is allocated in the NSF, that is, the left side of the equation (5) minus the right side thereof. Thus, each partition may comprise one or more successive UEs in the descending order that are to be arranged in the NSFs and correspondingly remaining one or more successive UEs in the descending order that are to be arranged in the PSFs. Alternatively, in some embodiment s are sorted in an ascending order according to the marginal benefit

and thus the each partition comprises one or more successive UEs in the ascending order that are to be arranged in the PSFs and correspondingly one or more successive UEs that are to be arranged in the NSFs. Hence, the method 500, at step S509, would arrange first j UEs in the PSFs and arrange the rest of UEs in the NSFs.

As a further alternative, a different marginal benefit difference concrete expression is omitted herein for simplicity) can be derived by

subtraction of the marginal benefit obtained if the j ' UE is allocated in the NSF from the one obtained if the UE is allocated in the PSF, that is, the right side of the equation (5) minus the left side thereof. Likewise, if the UEs are sorted in a descending order according to the different marginal benefit

then each partition may comprise one or more successive UEs that are to be arranged in the PSFs and correspondingly remaining one or more successive UEs that are to be arranged in the ASFs. Thus, the method 500, at step S509, would arrange first j UEs in the PSFs and arrange the rest of UEs in the ASFs. Alternatively, in some embodiments, the UEs may also be sorted in an ascending order according to the different marginal benefit

, and thus the each partition may comprise one or more successive UEs that are to be arranged in the NSFs and correspondingly the rest of successive UEs that are to be arranged in the PSFs. Hence, the method 500, at step S509, would arrange first j UEs in the NSFs and arrange the rest of UEs in the PSFs.

[0120] It can be seen from the above that the functions and equations as used by the present invention may have different concrete expressions and should not be limited to specific expressions. A person skilled in the art can select any other suitable expressions to practice the present invention based upon the teachings as presented herein. Further, it should be noted herein that the steps and execution order as illustrated Fig. 5 are only examples and are not restrictive to the present invention. Those skilled in the art, after reading the present specification, can change these steps, for example, by omitting, combining, or adding certain steps, changing the execution order of certain steps so as to adapt to different application demands.

[0121] Fig. 6 is a flow chart schematically illustrating a method 600 for resource allocation according to an embodiment of the present invention. As illustrated in Fig. 6, the method 600 starts at step S601 and proceeds to step S602, at which the method 600 sets an initial β , i.e., configures an initial ABS pattern, and may send the initial ABS pattern to the one or more interfered BS or other interfering BSs, although not shown. Based upon the initial β , it may schedule its own served UEs on the NSFs. After a certain amount of time, the method 600 receives or collects, at step S603, an item R_\ from one or more other BSs including the protected BS as discussed in Fig. 5.

[0122] With respect to a protected BS, the item Ri may comprise two items Rf and

Rf as expressed in the equations (2) and (3) under the presently used β (i.e., presently used

ABS pattern). As previously discussed, the first item Rf is a first amount of data transmitted by the protected BS if a time period of an ABS configuration is completely occupied by the NSFs and the second item Rf is a second amount of data transmitted by the protected BS if the time period of the ABS configuration is completely occupied by the PSFs. With respect to an interfering BS, the item ?jmay only comprise the item Rf since the UEs as served by the interfered BS would be scheduled or arranged only in the NSFs.

[0123] Then, based upon the received R„ a utility function U_n for a protected BS n may be expressed as below:

[0124J U_n

^~ ,, ΐβ^~ (13)

[0125] A utility function U_n for an interfering BS n may be expressed as below:

[0126] ^υ _η ^{= Κ}Λ^{ι ~ β) ~} ^_{} (14)}

[0127] where the meanings of items in the equations (13) and (14) are the same as the aforementioned.

[0128] Ajoint utility function U_Jgint then can be given as below:

[0129] U_Joial = (15)

[0130] where N denotes a total number of BSs in the current system in which the ABS configuration has been applied.

[0131] By maximizing the joint utility function U_j0m. and setting U_n , & new ABS pattern can be generated and thus the item

β can be delivered to each BS in the current system including the protected BS as discussed in Fig. 5.

[0132] Given the situation in which the center controller is located in an interfering BS, the method 600, at step S604, arranges the UEs as served by the interfering BS in the NSFs. Finally, the method 600 ends at step S605.

[0133] In some embodiments, if the value of the item β has been converged or kept unchanged for a while, then the center controller may signal other BSs in the system not to send the information regarding the amounts of data such that the wireless resources could be saved, hi yet other embodiments, if some predetermined events occur or some predetermined time periods expire, then the procedure of determining the best β should be launched again.

[0134] The foregoing has discussed the details regarding updating the ABS pattern in connection with Fig. 6, it should be noted that the present invention is not limited thereto. For example, although specific utility and joint utility functions have been disclosed herein, the present invention is not limited thereto and other suitable forms of the utility and joint utility functions may also be applicable to the present invention. For instance, when the items R, all

1 and J? j are calculated based upon the equations (8) and (9), then the utility function and the (16)

(17)

[0138] where » denotes the n_th BS, the equation (16) is for a protected BS and the equation (17) is for an interfering BS.

[0139] Fig. 7 illustrates a simplified block diagram of a BS 701 and a UE 702 that are suitable for use in practicing the exemplary embodiments of the present invention. In Fig. 7, a wireless network is adapted for communication with the UE 702, which may be embodied as a protected UE, via the BS (macro eNB, interfering BS or a interfered BS) 701. The UE 702, among other things, may include a data processor (DP) 703, a memory (MEM) 704 coupled to the DP 703, and a suitable RF transmitter TX and receiver RX 705 coupled to the DP 703. The MEM 704 stores a program (PROG) 707. The TX/RX 705 is for bidirectional wireless communications with the BS 701.

[0140] The BS 701 includes a data processor (DP) 707, a memory (MEM) 708 coupled to the DP 707, and a suitable RF transmitter TX and receiver RX 709 coupled to the DP 707. The MEM 708 stores a program (PROG) 710. The TX/RX 709 is for bidirectional wireless communications with the UE 702. Note that the TX RX 709 has at least one antenna to facilitate communication, though in practice a BS will typically have several. The BS 701 may be connected via a data path with one or more external networks or systems, such as an internet.

[0141] At least one of the PROGs 706 and 710 may include program instructions that, when executed by the associated DPs 703 and 707, enable the UE 702 and BS 701 to operate in accordance with the exemplary embodiments of this invention, as discussed previously with the methods 200-600.

[0142] The MEMs 704 and 708 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. While only one MEM is shown in the BS 701 or UE 702, there may be several physically distinct memory units in the BS 701 or UE 702.

[0143] The DPs 703 and 707 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, DSPs and processors based on multicore processor architecture, as non limiting examples. Either or both of the UE 702 and the BS 701 may have multiple processors, such as for example an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[0144] The embodiments of the present invention may be implemented by computer software executable by one or more of the DPs 703, 707 of the UE 702 and the BS 701, or by hardware, or by a combination of software and hardware.

[0145] Exemplary embodiments of the present invention have been described above with reference to block diagrams and flowchart illustrations of methods and apparatuses. It will be understood that each block of the block diagrams and flowchart illustrations, and combinations of blocks in the block diagrams and flowchart illustrations, respectively, can be implemented by various means including computer program instructions. These computer program instructions may be loaded onto a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions which execute on the computer or other programmable data processing apparatus create means for implementing the functions specified in the flowchart block or blocks.

[0146] Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims.

Claims

What is claimed is:

1. A method for resource allocation, comprising:

a) sorting a plurality of user equipments in an order according to respective marginal benefit difference of each of the plurality of user equipments, wherein the respective marginal benefit difference indicates difference between the marginal benefit obtained if the user equipment is arranged in a normal subframe and the marginal benefit obtained if the user equipment is arranged in a protected subframe according to an almost blank subframe pattern; b) repeatedly partitioning the plurality of sorted user equipments to form a plurality of unique partitions, each unique partition consisting of one or more successive user equipments in the order that are to be arranged in normal subframes and correspondingly remaining one or more successive user equipments in the order that are to be arranged in protected subframes; c) calculating a utility function for each of the plurality of unique partitions to determine one of the plurality of unique partitions that maximizes the utility function;

d) recording a result of the maximized utility function;

e) using the determined partition to update the respective marginal benefit difference; f) repeatedly performing steps a)-e) with the updated respective marginal benefit difference until the result of the currently recorded maximized utility function is less than that of the immediately previously recorded maximized utility function; and

g) arranging, according to the partition which corresponds to the immediately previously maximized utility function, each of the plurality of user equipments in the normal subframe or the protected subframe.

2. The method as recited in Claim 1, further comprising:

receiving the almost blank subframe pattern from an external entity.

3. The method as recited in Claim 2, further comprising:

calculating a first amount of data transmitted by a protected BS if a time period of an almost blank subframe configuration is completely occupied by the normal subframes;

calculating a second amount of data transmitted by the protected BS if the time period of the almost blank subframe configuration is completely occupied by the almost blank subframes; sending information regarding the first and second amounts of data to the external entity for updating the almost blank subframe pattern; and

stopping sending the information upon receipt of a stopping instruction from the external entity.

4. The method as recited in Claim 1, wherein the respective marginal benefit difference is calculated by subtracting the marginal benefit obtained if the user equipment is arranged in the protected subframe from the marginal benefit obtained if the user equipment is arranged in the normal subframe.

5. The method as recited in Claim 4, wherein the sorting the plurality of user equipments in the order comprises sorting the plurality of user equipments in a descending order, and the each partition comprises one or more successive user equipments in the descending order that are to be arranged in the normal subframes and correspondingly remaining one or more successive user equipments in the descending order that are to be arranged in the protected subframes.

6. The method as recited in Claim 4, wherein the sorting the plurality of user equipments in the order comprises sorting the plurality of user equipments in an ascending order, and the each partition comprises one or more successive user equipments in the ascending order that are to be arranged in the protected subframes and correspondingly remaining one or more successive user equipments that are to be arranged in the normal subframes.

7. The method as recited in Claim 1, wherein the respective marginal benefit difference is calculated by subtracting the marginal benefit obtained if the user equipment is arranged in the normal subframe from the marginal benefit obtained if the user equipment is arranged in the protected subframe.

8. The method as recited in Claim 7, wherein the sorting the plurality of user equipments in the order comprises sorting the plurality of user equipments in a descending order, and the each partition comprises one or more successive user equipments in the descending order that are to be arranged in the protected subframes and correspondingly remaining one or more successive user equipments in the descending order that are to be arranged in the normal subframes.

9. The method as recited in Claim 7, wherein the sorting the plurality of user equipments in the order comprises sorting the plurality of user equipments in an ascending order, and the each partition comprises one or more successive user equipments in the ascending order that are to be arranged in the normal subframes and correspondingly remaining one or more successive user equipments that are to be arranged in the protected subframes.

10. A method for resource allocation, comprising:

receiving, from one or more BSs, information regarding at least one of a first amount of data if a time period of an almost blank subframe configuration is completely occupied by normal subframes and a second amount of data if the time period of the almost blank subframe configuration is completely occupied by almost blank subfrarnes;

forming, based upon the information, a respective utility function of each of the one or more BSs; and

determining an almost blank subframe pattern which maximizes a result of a joint utility function, wherein the joint utility function is obtained by operations on all the respective utility functions of the one or more BSs.

11. The method as recited in Claim 10, wherein the base station is a protected base station and the information relate to the first and second amounts of data.

12. The method as recited in Claim 10, wherein the base station is an interfering base station and the information relates to the first amount of data.

13. The method as recited in any of Claims 10-12, further comprising:

updating the almost blank subframe pattern based upon newly received information regarding the amount of data or based upon an event; and

sending the updated almost blank subframe pattern to the one or more base stations.

14. The method as recited in Claim 13, further comprising:

instructing the one or more base stations not to send the information when the updated almost blank subframe pattern has been converged.

15. An apparatus for resource allocation, comprising:

a) means for sorting a plurality of user equipments in an order according to respective marginal benefit difference of each of the plurality of user equipments, wherein the respective marginal benefit difference indicates difference between the marginal benefit obtained if the user equipment is arranged in a normal subframe and the marginal benefit obtained if the user equipment is arranged in a protected subframe according to an almost blank subframe pattern; b) means for repeatedly partitioning the plurality of sorted user equipments to form a plurality of unique partitions, each unique partition consisting of one or more successive user equipments in the order that are to be arranged in normal subfrarnes and correspondingly remaining one or more successive user equipments in the order that are to be arranged in protected subfrarnes;

c) means for calculating a utility function for each of the plurality of unique partitions to determine one of the plurality of unique partitions that maximizes the utility function;

d) means for recording a result of the maximized utility function;

e) means for using the determined partition to update the respective marginal benefit difference;

f) means for instructing means a)-e) to repeatedly perform with the updated respective marginal benefit difference until the result of the currently recorded maximized utility function is less than that of the immediately previously recorded maximized utility function; and

g) means for arranging, according to the partition which corresponds to the immediately previously maximized utility function, each of the plurality of user equipments in the normal subframe or the protected subframe.

16. The apparatus as recited in Claim 15, further comprising:

means for receiving the almost blank subframe pattern from an external entity.

17. The apparatus as recited in Claim 16, further comprising:

means for calculating a first amount of data transmitted by a protected base station if a time period of an almost blank subframe configuration is completely occupied by the normal subframes;

means for calculating a second amount of data transmitted by the protected base station if the time period of the almost blank subframe configuration is completely occupied by the almost blank subframes;

means for sending information regarding the first and second amounts of data to the external entity for updating the almost blank subframe pattern; and

means for stopping sending the information upon receipt of a stopping instruction from the external entity.

18. The apparatus as recited in Claim 15, wherein the respective marginal benefit difference is calculated by subtracting the marginal benefit obtained if the user equipment is arranged in the protected subframe from the marginal benefit obtained if the user equipment is arranged in the normal subframe.

19. The apparatus as recited in Claim 18, wherein the means for sorting the plurality of user equipments in the order comprises means for sorting the plurality of user equipments in a descending order, and the each partition comprises one or more successive user equipments in the descending order that are to be arranged in the normal subframes and correspondingly remaining one or more successive user equipments in the descending order that are to be arranged in the protected subframes.

20. The apparatus as recited in Claim 18, wherein the means for sorting the plurality of user equipments in the order comprises means for sorting the plurality of user equipments in an ascending order, and the each partition comprises one or more successive user equipments in the ascending order that are to be arranged in the protected subframes and correspondingly remaining one or more successive user equipments that are to be arranged in the normal subframes.

21. The apparatus as recited in Claim 15, wherein the respective marginal benefit difference is calculated by subtracting the marginal benefit obtained if the user equipment is arranged in the normal subframe from the marginal benefit obtained if the user equipment is arranged in the protected subframe.

22. The apparatus as recited in Claim 21 , wherein the means for sorting the plurality of user equipments in the order comprises means for sorting the plurality of user equipments in a descending order, and the each partition comprises one or more successive user equipments in the descending orders that are to be arranged in the protected subframes and correspondingly remaining one or more successive user equipments in the descending order that are to be arranged in the normal subframes.

23. The apparatus as recited in Claim 21, wherein the means for sorting the plurality of user equipments in the order comprises means for sorting the plurality of user equipments in an ascending order, and the each partition comprises one or more successive user equipments in the ascending order that are to be arranged in the normal subframes and correspondingly remaining one or more successive user equipments that are to be arranged in the protected subframes.

24. An apparatus for resource allocation, comprising:

means for receiving, from one or more base stations, information regarding at least one of a first amount of data if a time period of an almost blank subframe configuration is completely occupied by normal subframes and a second amount of data if the time period of the almost blank subframe configuration is completely occupied by almost blank subframes;

means for forming, based upon the information, a respective utility function of each of the one or more base stations; and

means for determining an almost blank subframe pattern which maximizes a result of a joint utility function, wherein the joint utility function is obtained by operations on all the respective utility functions of the one or more base stations.

25. The apparatus as recited in Claim 24, wherein the base station is a protected base station and the information relate to the first and second amounts of data.

26. The apparatus as recited in Claim 24, wherein the base station is an interfering base station and the information relates to the first amount of data.

27. The apparatus as recited in any of Claims 24-26, further comprising:

means for updating the almost blank subframe pattern based upon newly received information regarding the amount of data or based upon an event; and

means for sending the updated almost blank subframe pattern to the one or more base stations.

28. The apparatus as recited in Claim 27, further comprising:

means for instructing the one or more base stations not to send the information when the updated almost blank subframe pattern has been converged.

29. An apparatus for resource allocation, comprising:

at least one processor and at least one memory including compute program code, the memory and the computer program code configured to cause the apparatus at least to:

a) sort a plurality of user equipments in an order according to respective marginal benefit difference of each of the plurality of user equipments, wherein the respective marginal benefit difference indicates difference between the marginal benefit obtained if the user equipment is arranged in a normal subframe and the marginal benefit obtained if the user equipment is arranged in a protected subframe according to an almost blank subframe pattern;

b) repeatedly partition the plurality of sorted user equipments to form a plurality of unique partitions, each unique partition consisting of one or more successive user equipments in the order that are to be arranged in normal subframes and correspondingly remaining one or more successive user equipments in the order that are to be arranged in protected subframes; c) calculate a utility function for each of the plurality of unique partitions to determine one of the plurality of unique partitions that maximizes the utility function;

d) record a result of the maximized utility function;

e) use the determined partition to update the respective marginal benefit difference;

f) repeatedly perform steps a)-e) with the updated respective marginal benefit difference until the result of the currently recorded maximized utility function is less than that of the immediately previously recorded maximized utility function; and

g) arrange, according to the partition which corresponds to the immediately previously maximized utility function, each of the plurality of user equipments in the normal subframe or the protected subframe.

30. An apparatus for resource allocation, comprising:

receive, from one or more base stations, information regarding at least one of a first amount of data if a time period of an almost blank subframe configuration is completely occupied by normal subframes and a second amount of data if the time period of the almost blank subframe configuration is completely occupied by almost blank subframes; form, based upon the information, a respective utility function of each of the one or more base stations; and

determine an almost blank subframe pattern which maximizes a result of a joint utility function, wherein the joint utility function is obtained by operations on all the respective utility functions of the one or more base stations.