CN105323776A - Uplink interference coordination method - Google Patents

Abstract

The invention discloses an uplink interference coordination method comprising the following steps: sharing downlink reference transmitted power between neighbor cells and cross-layer cells; estimating the interference value of a user to a neighbor cell based on the neighbor cell downlink reference signal transmitted power, the neighbor cell downlink reference signal received power and the user service channel received power; comparing the interference value of the user with a preset interference threshold, and marking the user as an interference source user if the interference value of the user is greater than the preset interference threshold; and performing an interference coordination operation on the interference source user. By adopting the technical scheme of the invention, strong interference between cells can be effectively staggered, and the performance of the interference coordination algorithm can be further guaranteed.

Description

A kind of up-link interference coordination method

Technical field

The application relates to wireless communication technology field, particularly relates to a kind of up-link interference coordination method.

Background technology

Based on the cellular radio Communication system of OFDM access (OFDMA) technology, such as LTE, WIMAX system, intra-cell users realizes the orthogonal of signal by frequency division, solves the problem of intra-cell interference better.But as cost, during identical networking, stronger presence of intercell interference can be brought.Specifically, Cell Edge User is away from serving BS, and the received power of useful signal is lower, and be therefore more easily interfered impact; Meanwhile, Cell Edge User, close to adjacent cell, in upstream data process of transmitting, also easilier causes interference to adjacent cell.Therefore, how accurately cell of origin edge customer, and control to suppress presence of intercell interference by band plan or power, be the important subject of Inter-Cell Interference Coordination technology.

In actual arranging net, because the landform, architectural composition etc. of overlay area are variant, the coverage of neighbor cell is often different.When coverage difference is larger, easily produce asymmetric serious uplink interference, the community that mainly coverage is larger is to the interference of the less community of coverage.The edge customer distance service base station of the community that coverage is larger is far away, in order to overcome the impact of path loss, can send with larger power, and the path loss arriving the less adjacent cell of coverage is less, the uplink interference power then arriving adjacent cell is comparatively large, causes stronger uplink interference.In like manner, under heterogeneous network scene, between macrocell and low power nodes, also there is the uplink interference of macrocell user to small-cell.

In order to effectively suppress this asymmetric uplink interference, need to carry out accurate location interference source user by effective means, user divided into groups according to annoyance level, the interference coordination technique such as or power control multiplexing with frequency band are combined, to reduce interference.

Existing interference source user decision method mainly utilizes the difference of the pilot signal reception power (RSRP, ReferenceSignalReceivedPower) of Serving cell and adjacent cell to judge.When the difference of the pilot signal reception power of Serving cell and adjacent cell is lower than certain thresholding, then think that user is uplink interference source user.Thus by this part user scheduling to planning frequency band on or carry out inter-cell power control, avoid the strong jamming between user, reach the effect of AF panel.But this prior art roughly can only judge that user position is in the cell near center or keeps to the side, or whether user is near adjacent cell, effectively cannot reflect the uplink interference situation that user causes adjacent area.Especially for when between neighbor cell, coverage difference is larger, the asymmetric serious uplink interference of existence, is difficult to accurate location interference source user by existing method, can affects the performance of interference coordination.This is because uplink interference is the interference that user arrives neighbor base station, annoyance level and user's expectation received power, and user is relevant with the path loss difference of adjacent cell to Serving cell.

User to the uplink interference power of adjacent area and user to the uplink received power of Serving cell between pass be:

Prx _interference＝Prx _desired-ΔPL(1)

In formula (1), Prx _interferencefor user is to the uplink interference power of adjacent area; Prx _desiredfor user is to the useful signal received power of Serving cell; Δ PL=PL _neighbor-PL _service, be that user is to adjacent area and the difference to the path loss of Serving cell.

Because base station down pilot signal transmitted power is directly proportional to cell coverage area often, namely coverage is larger, descending pilot frequency power is larger, otherwise less.Between this neighbor cell that coverage is differed greatly or cross-layer community, base station down pilot tone transmitted power difference is also larger.Therefore, the path loss difference that the difference of cell downlink pilot signal reception power (RSRP) that user's measurement reports can not be used between equivalent neighbor cell or cross-layer community.As can be seen from the derivation of following formula, the difference of neighbor cell descending pilot frequency power is the difference of neighbor cell descending pilot frequency transmitted power and the user summation to the difference of neighbor cell path loss.

Prx _s＝Ptx _s-PL _s

Prx _l＝Ptx _l-PL _l(2)

Prx _s-Prx _l＝(Ptx _s-Ptx _l)+(PL _l-PL _s)

In formula (2), Prx _sthe down-bound pilot frequency signal received power of the community that the coverage reported for user's measurement is less; Prx _lthe down-bound pilot frequency signal received power of the community that the coverage reported for user's measurement is larger; Ptx _sfor the down-bound pilot frequency signal transmitted power of the less community of coverage; Ptx _lfor the down-bound pilot frequency signal transmitted power of the larger community of coverage; PL _sfor user is to the path loss of the less community of coverage; PL _lfor user is to the path loss of the larger community of coverage;

Therefore, in order to improve the performance of Inter-Cell Interference Coordination technology further, improve the uplink interference between adjacent area that cross-layer community and coverage differ greatly, need to share down-bound pilot frequency signal transmitted power between neighbor cell, so that accurate locating interference source in up going route user.But, sharing of transmitted power can be carried out between undefined base station in the technical specification that existing LTE/LTE-A is correlated with and standard, but this is unfavorable for solving the uplink interference problem that adjacent area coverage differs greatly.

Summary of the invention

This application provides a kind of up-link interference coordination method, minizone strong jamming of can effectively staggering, ensure the performance of interference coordination algorithm further.

A kind of up-link interference coordination method that the embodiment of the present application provides, comprises the steps:

Descending pilot frequency transmitted power is shared between A, neighbor cell, cross-layer community;

B, the interference value utilizing adjacent area down-bound pilot frequency signal transmitted power, adjacent area down-bound pilot frequency signal received power and user traffic channel received power to carry out estimating user to cause adjacent area;

C, the interference value of user to be compared with the interference threshold preset, if be greater than described threshold value, described user is labeled as interference source user;

D, interference coordination operation is carried out for interference source user.

Preferably, for the neighbor cell belonging to same base station, share cell downlink pilot signal transmitted power by interior message of standing.

Preferably, for the neighbor cell belonging to different base station, share cell downlink pilot signal transmitted power based on X2 mouth.

Preferably, describedly share cell downlink pilot signal transmitted power based on X2 mouth and comprise: the descending pilot frequency transmitted power being realized minizone by the reference signal power information cell increasing Serving cell in X2 process of establishing and/or base station configuration updating process is shared.

Preferably, step B comprises:

According to the interference value that following formulae discovery user i causes adjacent area

P _{UL_Rx_NeighbourCell}(i)＝P _{UL_Rx_ServingCell}(i)-ΔPL(i)；

Wherein, P _{uL_Rx_NeighbourCell}i interference that () causes adjacent cell for user i, P _{uL_Rx_ServingCell}i () is for user i is in the Traffic Channel received power of serving BS; Δ PL (i) is obtained by following formulae discovery:

ΔPL(i)＝(Ptx _Neighbour-Ptx _Serving)-(RSRP _Neighbour(i)-RSRP _Serving(i))

Wherein, Ptx _neighborfor adjacent area descending pilot frequency transmitted power; Ptx _servingfor Serving cell descending pilot frequency transmitted power; RSRP _neighbor(i) and RSRP _servingi () is respectively the down-bound pilot frequency signal received power of adjacent cell that user i measurement reports and Serving cell.

Preferably, step D comprises: make interference source user avoid the edge band of adjacent area when Resources allocation; Or, by inter-cell power control, reduce the transmitted power of interference source user.

As can be seen from the above technical solutions, descending pilot frequency transmitted power is shared between neighbor cell, cross-layer community, and carry out the interference that effective estimating user causes adjacent area accordingly, to determine that whether user is interference source user, and then carry out interference coordination operation to interference source user.Technical scheme can the interference effect that causes adjacent cell of estimating user more accurately, and divides the group belonging to user, thus minizone strong jamming of more effectively staggering, ensure the performance of interference coordination algorithm further.

Accompanying drawing explanation

The up-link interference coordination method schematic flow sheet that Fig. 1 provides for the embodiment of the present application.

Embodiment

A kind of up-link interference coordination method that the application provides, its fundamental design idea is: share descending pilot frequency transmitted power between neighbor cell, cross-layer community, and carrys out the interference that effective estimating user causes adjacent area accordingly, to determine whether user is interference source user.Wherein dissimilar multiple communities are disposed in same overlay area under referring to heterogeneous network scene in cross-layer community, as macrocell and Microcell.

For making the know-why of technical scheme, feature and technique effect clearly, below in conjunction with specific embodiment, technical scheme is described in detail.

The up-link interference coordination method flow process that the embodiment of the present application provides as shown in Figure 1, comprises the steps:

Step 101: share descending pilot frequency transmitted power between neighbor cell, cross-layer community.

Step 102: the interference value utilizing adjacent area down-bound pilot frequency signal transmitted power, adjacent area down-bound pilot frequency signal received power (RSRP) and user traffic channel received power to carry out estimating user to cause adjacent area.

Step 103: compared with the interference threshold preset by the interference value of user, if be greater than described threshold value, is labeled as interference source user by described user.

Step 104: interference coordination operation is carried out for interference source user.

In the embodiment of the present application, for the neighbor cell belonging to same base station, share cell downlink pilot signal transmitted power by interior message of standing; For the neighbor cell belonging to different base station, share cell downlink pilot signal transmitted power based on X2 mouth.

In another embodiment of the application, the descending pilot frequency transmitted power being realized minizone by the reference signal power information cell (ReferenceSignalPowerIE) increasing Serving cell in X2 foundation (Setup) process and/or base station configuration updating (eNBConfigurationUpdate) process is shared.

Such as, newly-increased IE-ReferenceSiganlPowerIE in the signaling message X2SETUPREQUEST message, ENBCONFIGURATIONUPDATE message of X2 mouth, implication is the every Resource Unit capacity of downlink reference signal (EPRE, TransmitEnergyperResourceElement), span (-60,50), related definition can with reference to TS36.213.Described definition is only for example, not in order to limit the present invention.

The interference utilizing adjacent area down-bound pilot frequency signal transmitted power, adjacent area down-bound pilot frequency signal received power (RSRP) and user traffic channel received power to carry out estimating user to cause adjacent area, concrete computational process is as follows:

P _{UL_Rx_NeighbourCell}(i)＝P _{UL_Rx_ServingCell}(i)-ΔPL(i)[dBm](3)

Wherein, P _{uL_Rx_NeighbourCell}i interference that () causes adjacent cell for user i, P _{uL_Rx_ServingCell}i (), for user i is in the Traffic Channel received power of serving BS, can be recorded by serving BS, or calculated by the path loss to serving BS of user's transmitted power and reporting of user.Δ PL (i) can be obtained by following formulae discovery:

ΔPL(i)＝PL _Neighbour(i)-PL _Serving(i)

＝(Ptx _Neighbour-RSRP _Neighbour(i))-(Ptx _Serving-RSRP _Serving(i))[dB](4)

＝(Ptx _Neighbour-Ptx _Serving)-(RSRP _Neighbour(i)-RSRP _Serving(i))

Wherein, Ptx _neighborfor adjacent area descending pilot frequency transmitted power, serving BS is obtained by X2 mouth message; Ptx _servingfor Serving cell descending pilot frequency transmitted power; RSRP _neighbor(i) and RSRP _servingi () is respectively the down-bound pilot frequency signal received power of adjacent cell that user i measurement reports and Serving cell.

By following rule, Serving cell determines whether user i is interference source user:

$\left\{\begin{array}{cc}{}^{\&prime;}{1}^{\&prime;},& \mathrm{if}{P}_{\mathrm{UL}\_\mathrm{Rx}\_\mathrm{NeighbourCell}}\left(i\right)\&GreaterEqual;I_{\mathrm{Threshold}}\\ {}^{\&prime;}{0}^{\&prime;},& \mathrm{if}{P}_{\mathrm{UL}\_\mathrm{Rx}\_\mathrm{NeighbourCell}}\left(i\right)<I_{\mathrm{Threshold}}\end{array}\right.---\left(4\right)$

Wherein ' 1' represent it is interference source user, ' 0' represents it is not interference source user.I _thresholdbe the required interference threshold selecting interference source user, specifically can arrange according to the interference power distribution situation in system.I _thresholdtime less, interference decision threshold is low, and the interference source user selected is more; And I _thresholdtime larger, interference decision threshold improves, and can reduce the judgement quantity of edge customer.

Interference coordination operation is carried out for interference source user include but not limited to: make interference source user avoid the edge band of adjacent area when Resources allocation; Or by inter-cell power control, reduce the transmitted power of interference source user, thus avoid or reduce the strong jamming to adjacent cell.Corresponding strategies depends on the specific implementation of interference coordination, and the application is not in order to limit the specific implementation of interference coordination.

The foregoing is only the preferred embodiment of the application; not in order to limit the protection range of the application; within all spirit in technical scheme and principle, any amendment made, equivalent replacements, improvement etc., all should be included within scope that the application protects.

Claims (6)

1. a up-link interference coordination method, is characterized in that, comprises the steps:

Descending pilot frequency transmitted power is shared between A, neighbor cell, cross-layer community;

B, the interference value utilizing adjacent area down-bound pilot frequency signal transmitted power, adjacent area down-bound pilot frequency signal received power and user traffic channel received power to carry out estimating user to cause adjacent area;

C, the interference value of user to be compared with the interference threshold preset, if be greater than described threshold value, described user is labeled as interference source user;

D, interference coordination operation is carried out for interference source user.

2. method according to claim 1, is characterized in that, for the neighbor cell belonging to same base station, shares cell downlink pilot signal transmitted power by interior message of standing.

3. method according to claim 1, is characterized in that, for the neighbor cell belonging to different base station, shares cell downlink pilot signal transmitted power based on X2 mouth.

4. method according to claim 1, it is characterized in that, describedly share cell downlink pilot signal transmitted power based on X2 mouth and comprise: the descending pilot frequency transmitted power being realized minizone by the reference signal power information cell increasing Serving cell in X2 process of establishing and/or base station configuration updating process is shared.

5. method according to claim 1, is characterized in that, step B comprises:

According to the interference value that following formulae discovery user i causes adjacent area

P _{UL_Rx_NeighbourCell}(i)＝P _{UL_Rx_ServingCell}(i)-ΔPL(i)；

Wherein, P _{uL_Rx_NeighbourCell}i interference that () causes adjacent cell for user i, P _{uL_Rx_ServingCell}i () is for user i is in the Traffic Channel received power of serving BS; Δ PL (i) is obtained by following formulae discovery:

ΔPL(i)＝(Ptx _Neighbour-Ptx _Serving)-(RSRP _Neighbour(i)-RSRP _Serving(i))

Wherein, Ptx _neighborfor adjacent area descending pilot frequency transmitted power; Ptx _servingfor Serving cell descending pilot frequency transmitted power; RSRP _neighbor(i) and RSRP _servingi () is respectively the down-bound pilot frequency signal received power of adjacent cell that user i measurement reports and Serving cell.

6. method according to claim 1, is characterized in that, step D comprises: make interference source user avoid the edge band of adjacent area when Resources allocation; Or, by inter-cell power control, reduce the transmitted power of interference source user.