CN102625316B - Random back-off distributed coordination scheduling method - Google Patents

Abstract

The invention provides a random back-off distributed coordination scheduling method, which includes independently scheduling users in every sector through a proportional fair scheduling principle; selecting coordination sectors according to types of scheduled users, namely, users in sectors or users at the edge of sectors; broadcasting own scheduling information to the coordination sectors after finishing the independent scheduling and determining the coordination sectors through every sector; and processing scheduling conflicts among sectors through a random back-off interference coordination mechanism to perform scheduling coordination among sectors, based on the scheduling information of the own sector and other sectors. According to the random back-off distributed coordination scheduling method, the distributed processing of coordination scheduling is achieved and can be achieved in existing network structures, and the performance of users at the edge of sectors is improved greatly.

Description

A kind of distributed coordination dispatching method of random back

Technical field

The invention belongs to wireless communication technology field, particularly a kind of distributed coordination dispatching technique of random back.

Background technology

In order to make full use of limited frequency spectrum resource, adopt full rate multiplexing scheme.And in the time that network using full rate is multiplexing, system is in interference-limited state, particularly Cell Edge User.In order to eliminate user's interference, improve the spectrum efficiency of cell spectrum efficiency and Cell Edge User, coordinated scheduling technology has been proposed.Jointly cooperated by multiple communities, eliminate the interference to other communities.Due to Combined Treatment between coordinated scheduling Technology Need community, combined optimization, needs a large amount of information interactions between community, and needs Centroid to process the problems such as coordination, is difficult to realize under the existing network architecture.

Summary of the invention

The object of the invention is the problem in order to overcome the global optimization of existing coordinated scheduling Technology Need, in order to realize coordinated scheduling technology under the existing network architecture, overcome a large amount of information interaction between the community that coordinated scheduling technology brings, and network-wide optimization problem, proposed a kind of distributed coordination dispatching method based on random back, the method has improved the spectrum efficiency of Cell Edge User in ensureing community average spectral efficiency (ase).

For achieving the above object, the present invention has adopted following technical scheme:

(1) each sector independence dispatched users of each website proportion of utilization equity dispatching principle Zhe community, in same sector, each Resource Block can only be distributed to a user;

(2) user after independent scheduling is divided into sector central user and sector-edge user, adopting coordinated scheduling technology is that sector-edge user is selected the needed cooperation of coordinated scheduling sector;

(3) determine that behind cooperation sector, You Zhe community is to the Cell Broadcast CB shared collaboration information at cooperation place, sector;

(4) each website is being received after the shared cooperative information in neighbor cell, if there is cooperation request neighbor cell to sector on Resource Block, judge whether the dispatched users on Resource Block is sector-edge user, if sector-edge user, carrying out random chance keeps out of the way, if sector central user, keeps out of the way from sector.

The concrete grammar of described step (1) is as follows:

To any time t, arbitrary cells n, distributes to user k by the Resource Block i of this this community of moment ^*, k ^*determined by following formula:

$k^{*}=\underset{k}{\arg \max }\frac{r_{\mathrm{kn}}\left(t\right)}{T_k}$

, r _kn(t) represent the peak transfer rate of user k on the n of community, T _krepresent the historical total throughout of user k, after the resource block assignments in each moment, historical throughput is pressed to T _k=T _k+ r _kn(t) upgrade, repeat said process until all sector resources are assigned, use I _s(k, i) represents the resource distribution indicator of sector s, I _s(k, i)=1 represents that i the resource block assignments of sector s is to user k, I _s(k, i)=0 represents that i the Resource Block of sector s is not yet assigned to user k.

The concrete grammar of described step (2) is as follows:

(2-1) division rule of class of subscriber

When user k meets time, judge that user k is as sector-edge user, when user k meets time, judge that user k is as sector central user, represent user k average received Signal to Interference plus Noise Ratio, γ _thrfor edge customer decision threshold, this threshold value can be determined by the ratio of sector-edge user;

(2-2) selection of cooperation type

By the user k selecting in step (1) ^*classify according to the division rule in (2-1), if user is k ^*for sector central user, adopt non-cooperation transmission scheme, only site-local is for its transmission data, if user is k ^*for sector-edge user, adopt coordinated scheduling transmission plan;

(2-3) cooperate in the coordinated scheduling selection of sector

If user is k ^*adopt coordinated scheduling transmission plan, user k ^*in all communities, select 2 sectors that interference signal is the strongest as the cooperation sector in coordinated scheduling

The concrete grammar of described step (3) is as follows:

Order the sector that represents to cooperate in the b of community comprises sector user set, if represent that website b needs sector on i Resource Block cooperation, if represent that website b does not need sector on i Resource Block cooperation, establish sector affiliated website is website b is to website the method of shared collaboration information is exactly will send to website

The concrete grammar of described step (4) is as follows:

I. initialization:

Order i=1, then enters step I i, represent website that receives is all for sector shared collaboration information, represent all sectors that need the Website Hosting of cooperation;

Ii. judged whether adjacent sites on Resource Block i to sector there is cooperation request:

If indicate collaborative demand, enter step I ii, if indicate without collaborative demand, enter step v;

Iii. judge sector the user k of the upper scheduling of Resource Block i ^*whether be sector-edge user:

If sector-edge user, enters step I v; If sector central user, order user k ^*from sector resource on piece i keep out of the way to reduce interference, enter step v;

Iv. Cell Edge User with probability keep out of the way:

Generate (0, a 1) equally distributed random number tempVal, if order user k ^*from sector resource Block i on keep out of the way, enter step v; If directly enter step v; P _thrwhile representing to have 1 collaborative demand, the probability that user keeps out of the way from respective resources piece;

V. make i=i+1, if i≤N gets back to step I i next Resource Block is coordinated;

If i > is N, finish sector scheduling coordinate, N represents the sum of Resource Block.

The present invention has following beneficial effect: first the present invention independently dispatches in each community, selects scheduled user, determines its cooperation cell by the type of dispatched users.Then by schedule information and the broadcast of request cooperative information, finally allow mechanism process the conflict of schedule information between community by keeping out of the way to return.Avoid introducing Centroid, under existing network framework, can be achieved.

Specific implementation method

Below in conjunction with embodiment, the invention will be further described.

Core concept of the present invention is: make Cell Edge User be disturbed seriously because full rate is multiplexing, poor-performing, therefore proposes coordinated scheduling technology.But the realization of coordinated scheduling technology needs global optimization, and need Centroid to dispatch, under existing framework, be difficult to realize.In order to overcome the problems referred to above, we propose a kind of distributed coordination dispatching technique of random back, and this community user is independently dispatched in each community, then the schedule information of Cell Broadcast CB oneself and cooperation request towards periphery.Community according to own scheduling letter and and the schedule information of other communities, if generation scheduling conflict adopts adaptive random back to return and allows technology complete the coordination of conflict.Avoid using Centroid, make each community can its scheduling of complete independently.

Embodiment

User MIMO cellular cell, this cellular cell comprises B community (Yi Ge community corresponding a website), and each community is divided into 3 sectors, and each sector identical user that distributes, adopts coordinated scheduling technology to disturb to eliminate between community between community.Comprise the following steps:

(1) independent scheduling in sector;

(2) selection of cooperation sector;

(3) between cooperation cell, schedule information is shared;

(4) minizone scheduling is coordinated;

Concrete steps are as follows:

(1) independent scheduling in sector, concrete steps are as follows:

Each website is independent to be dispatched this community user, and scheduling scheme is Proportional Fair, and scheme is as follows.

Proportional Fair strategy in community: to any time t, arbitrary cells n, distributes to user k by the Resource Block i of this this community of moment ^*, k ^*determined by following formula:

$k^{*}=\underset{k}{\arg \max }\frac{r_{\mathrm{kn}}\left(t\right)}{T_k}$

, r _kn(t) represent the peak transfer rate of user k on the n of community, T _krepresent the historical total throughout of user k, after the resource block assignments in each moment, need upgrade to historical throughput i.e. T _k=T _k+ r _kn(t).In order to ensure orthogonality in community, in same sector, each Resource Block can only be distributed to a user.Repeat said process until all resources (three sectors) are assigned.Might as well use I _s(k, i) represents the resource distribution indicator of sector s, if I _s(k, i)=1, represents that s i resource block assignments in sector is to user k, otherwise I _s(k, i)=0 represents to be not yet assigned to this user.

(2) selection of cooperation sector, concrete steps are as follows:

The first step: the user k that Proportional Fair in community is selected ^*classify

In the present invention, user has two types: user and sector-edge user in sector.User mainly determines its type according to the average received Signal to Interference plus Noise Ratio of pilot signal.If user k average received Signal to Interference plus Noise Ratio is when user k meets time, be judged to be Cell Edge User, otherwise be judged to be user in sector.Wherein γ _thrfor edge customer decision threshold.

Second step: dissimilar user adopts different transmission plans

If user is user in sector, adopt non-cooperation transmission scheme, only service node is its transmission data.If user k is sector-edge user, 2 the strongest sectors of user's selective reception signal in all communities add its cooperation set.

(3) between cooperation cell, schedule information is shared, and concrete steps are as follows:

Each website is after finishing scheduling, and the website at the place, cooperation sector that can select to local user sends the Resource Allocation Formula of this corresponding collaboration user in community.With set-inclusion sector cooperates in expression community b all users set, order obviously, if represent that website b needs sector on i Resource Block cooperation, otherwise represent not have collaborative demand.If sector affiliated website is website b and website the method of sharing schedule information is exactly will send to website

(4) minizone scheduling is coordinated, and concrete steps are as follows:

Each website receiving after the shared schedule information of adjacent cell, taking as according to this cell scheduling is coordinated, thereby realize cooperation.With website sector for example, receive all for sector shared schedule information wherein represent all sectors that need collaboration site) after, the scheduling scheme in this sector to be coordinated according to random back method, concrete steps are as follows:

I. initialization: order enter step I i.

Ii. judged whether adjacent sites on Resource Block n to sector there is cooperation request: if indicate collaborative demand, enter step I ii; Otherwise, enter step v.

Iii. judge sector the user k of the upper scheduling of Resource Block n ^*whether be Cell Edge User: if Cell Edge User enters step I v; Otherwise, user k ^*keep out of the way to reduce interference from this resource, even enter step v.

Iv. Cell Edge User with probability keep out of the way: generate (0, a 1) equally distributed random number tempVal, if user k ^*keep out of the way from this resource, even enter step v; Otherwise, directly enter step v.

V. make n=n+1, if n≤N gets back to step I i, next Resource Block is coordinated; Otherwise the scheduling that finishes this sector is coordinated.

In above-mentioned algorithm, we have adopted random back mechanism, wherein P to Cell Edge User _thrwhile representing to have 1 collaborative demand, the probability (its value can be determined by experience) that user keeps out of the way from respective resources piece.According to above-mentioned algorithm, on this Resource Block, ask cooperation if there are multiple nodes, the probability that user keeps out of the way from this Resource Block in sector that cooperates increases, this is rational, because the transmission meeting on this Resource Block brings severe jamming to the user of multiple neighbor cells, therefore keep out of the way the gain bringing more obvious.It is to keep out of the way for fear of cooperation both sides that Cell Edge User is adopted to random back mechanism simultaneously, causes the wasting of resources.

Claims (4)

1. a distributed coordination dispatching method for random back, is characterized in that, comprises the following steps:

(1) each sector independence dispatched users of each website proportion of utilization equity dispatching principle Zhe community, in same sector, each Resource Block can only be distributed to a user;

(2) user after independent scheduling is divided into sector central user and sector-edge user, adopting coordinated scheduling technology is that sector-edge user is selected the needed cooperation of coordinated scheduling sector;

(3) determine that behind cooperation sector, You Zhe community is to the Cell Broadcast CB shared collaboration information at cooperation place, sector;

(4) each website is being received after the shared cooperative information in neighbor cell, if there is cooperation request neighbor cell to sector on Resource Block, judge whether the dispatched users on Resource Block is sector-edge user, if sector-edge user, carrying out random chance keeps out of the way, if sector central user, keeps out of the way from sector;

The concrete grammar of described step (4) is as follows:

I. initialization:

Order i=1, then enters step I i, represent website that receives is all for sector shared collaboration information, represent all sectors that need the Website Hosting of cooperation;

Ii. judged whether adjacent sites on Resource Block i to sector there is cooperation request: if indicate collaborative demand, enter step I ii, if indicate without collaborative demand, enter step v;

Iii. judge sector the user k of the upper scheduling of Resource Block i ^*whether be sector-edge user:

If sector-edge user, enters step I v; If sector central user, order user k ^*from sector resource Block i on keep out of the way to reduce interference, enter step v;

Iv. Cell Edge User with probability keep out of the way:

Generate (0, a 1) equally distributed random number tempVal, if order user k ^*from sector resource Block i on keep out of the way, enter step v; If directly enter step v; P _thrwhile representing to have 1 collaborative demand, the probability that user keeps out of the way from respective resources piece;

V. make i=i+1, if i≤N gets back to step I i next Resource Block is coordinated; If i>N, finishes sector scheduling coordinate, N represents the sum of Resource Block.

2. a kind of distributed coordination dispatching method of random back according to claim 1, is characterized in that: the concrete grammar of described step (1) is as follows:

To any time t, arbitrary cells n, distributes to user k by the Resource Block i of this this community of moment ^*, k ^*determined by following formula:

$k^{*}=\underset{k}{\arg \max }\frac{r_{\mathrm{kn}}\left(t\right)}{T_k}$

, r _kn(t) represent the peak transfer rate of user k on the n of community, T _krepresent the historical total throughout of user k, after the resource block assignments in each moment, historical total throughout is pressed to T _k=T _k+ r _kn(t) upgrade, repeat said process until all sector resources are assigned, use I _s(k, i) represents the resource distribution indicator of sector s, I _s(k, i)=1 represents that i the resource block assignments of sector s is to user k, I _s(k, i)=0 represents that i the Resource Block of sector s is not yet assigned to user k.

3. a kind of distributed coordination dispatching method of random back according to claim 1, is characterized in that: the concrete grammar of described step (2) is as follows:

(2-1) division rule of class of subscriber

When user k meets time, judge that user k is as sector-edge user, when user k meets time, judge that user k is as sector central user, represent user k average received Signal to Interference plus Noise Ratio, γ _thrfor edge customer decision threshold;

(2-2) selection of cooperation type

By the user k selecting in step (1) ^*classify according to the division rule in (2-1), if user is k ^*for sector central user, adopt non-cooperation transmission scheme, only site-local is for its transmission data, if user is k ^*for sector-edge user, adopt coordinated scheduling transmission plan;

(2-3) cooperate in the coordinated scheduling selection of sector

If user is k ^*adopt coordinated scheduling transmission plan, user k ^*in all communities, select 2 sectors that interference signal is the strongest as the cooperation sector in coordinated scheduling

4. a kind of distributed coordination dispatching method of random back according to claim 1, is characterized in that: the concrete grammar of described step (3) is as follows:

Order the sector that represents to cooperate in website b comprises sector user set, if represent that website b needs sector on i Resource Block cooperation, if represent that website b does not need sector on i Resource Block cooperation, establish sector affiliated website is website b is to website the method of shared collaboration information is exactly will send to website