CN104038969A - CRE deviant and ABS joint configuration method for heterogeneous network - Google Patents

Abstract

The invention discloses a cell range expansion (CRE) deviant and almost blank subframe (ABS) joint configuration method for a heterogeneous network. The method comprises: in all UE accessed to a macro base station cell, determining a set M of alternative UE accessed to a micro base station cell through CRE; selecting UE from the set M to form a set N, and adjusting the number of ABSs to enable the following conditions to be simultaneously satisfied: the UE in the set N is accessed to the micro base station cell through the CRE and can satisfy service demands in the ABSs, the service demands of original UE in the micro base station can be satisfied in other downlink subframes apart from the ABSs, and the current number of the ABSs does not exceed an ABS maximum value under currently employed uplink/downlink configuration; and taking the current number of the ABSs as a recommended ABS number configuration value, and taking the maximum value of a difference between the power of a macro base station and the power of a micro base station which are received by the UE in the set N as a CRE deviant.

Description

A kind of CRE deviant for heterogeneous network and ABS associated disposition method

Technical field

The application relates to mobile communication technology field, relates in particular to a kind of cell coverage area for heterogeneous network expansion (CRE, Cell Range Expansion) and blank subframe (ABS, Almost Blank Subframe) associated disposition method almost.

Background technology

In heterogeneous network (HetNet), the mode that various dissimilar base stations adopt stratum to cover is disposed, if can not rationally solve the mutual interference problem of each minizone, certainly will bring very large impact to the transmission of network central control signaling processed, synchronizing signal, reference signal and data-signal.Therefore first, the interference coordination of minizone (ICIC, Inter-Cell Interference Coordination) problem becomes HetNet network design needs the difficult point solving.

At present on the basis of 3GPP standard R8/R9, in standard R10 primary study the interference coordination (eICIC) between enhancement type district, be intended to solve the coordinating district interference problem in HetNet heterogeneous network by more effective ICIC algorithm, comprising the ICIC technology based on carrier aggregation and non-carrier aggregation and from the ICIC of time domain angle.

If be connected to subscriber equipment (UE) number of microcell base station (Pico cell eNB), be far smaller than the UE number that is connected to macro cell base station (Macro cell eNB), will cause the unbalance of resource utilization.In order to improve microcell base station this consequences of causing different from macro cell base station transmitted power, be necessary to study new scheme and make user priority be switched to Microcell.For example the cell coverage area of current research is expanded (Cell Range Expansion, CRE), be about to the Reference Signal Received Power (RSRP of microcell base station, Reference Signal Receiving Power) add that certain deviant (bias) increases its descending coverage, by this, can make the macrocell edge customer that is close to Microcell select to be linked into Microcell.Although CRE can improve the cell load unbalance between macrocell and Microcell, but signal Qiang community while selecting due to possibility Bu Shiqi community, its Microcell, Serving cell of the UE in CRE coverage, so this UE can be subject to the strong descending interference in base station, adjacent macro cell.

Fig. 1 is the typical scene schematic diagram in heterogeneous network.Oval 101 represent the coverage of macro base station community, and oval 102 represent the coverage of micro-base station cell, and grey annular represents the coverage of micro-base station cell CRE.UE in macro base station community represents with MUE, and the UE in micro-base station cell represents with PUE.PUE106 is positioned at micro-base station cell CRE coverage, and to carry out signal mutual with micro-base station, is subject to the strong presence of intercell interference of macro base station simultaneously.

Time domain interference coordination be by invasion layer specifically almost blank subframe (ABS) reduce the be injured transfer of data of layer of actual transfer of data protection; this class ABS subframe requires only to send cell special reference (CRS; Cell-specific Reference Signals) and some necessary signals as broadcast channel (PBCH), master sync signal (PSS), auxiliary synchronous signals (SSS), not transmitting physical DSCH Downlink Shared Channel (PDSCH).When the layer of being injured is disturbed user when ABS subframe is dispatched, these users will be protected in the data service of ABS subframe transmission, avoids the strong presence of intercell interference of invasion layer.

At the CRE of HetNet heterogeneous network deviant and ABS, combine aspect configuration, prior art scheme adopts the method for system emulation mostly, under the scenes such as hypothetical network load level, user distribution, base station spacing, transmitted power, by traveling through the value of various CRE deviants and ABS, combine, obtain and make the maximized parameter configuration of network whole volume.This collocation method based on emulation obtains the parameter configuration of certain particular network scene only, cannot carry out dynamic-configuration according to real network situation, does not possess networking flexibility; Meanwhile, the method for the various parameter values of this traversal is brought high calculation process amount, and result is obtained slower, and is unfavorable for Product Cost Control; In addition, the resource allocation method of this pursuit entire system capacity is not considered if the configuration of ABS number too much, will to cause the restriction of ABS number the uplink mandate of macro base station community to issue, thereby the uplink of macro base station community is impacted.

Summary of the invention

The application provides a kind of CRE deviant for heterogeneous network and ABS associated disposition method, and having solved existing scheme cannot be according to the configuration of network truth dynamically-adjusting parameter, and operand is huge, and ignores the problem of ul transmissions performance.

A kind of CRE deviant for heterogeneous network and ABS associated disposition method that the embodiment of the present application provides, comprising:

A, the principle that accesses micro-base station cell higher Signal to Interference plus Noise Ratio when obtaining than access macro base station community by CRE based on user equipment (UE), in all UE of access macro base station community, determine the alternative UE set M that accesses micro-base station cell by CRE;

B, from set, choose UE M and form set N, and current ABS number is adjusted, following condition is met simultaneously: the UE in described set N is accessed micro-base station cell and can in ABS, be met business demand by CRE, in micro-base station cell, the business demand of original UE can be met in other descending sub frame except ABS, and current ABS number is no more than the ABS maximum under the uplink/downlink configuration of current employing;

C, using current ABS number as the ABS number Configuration Values of recommending, the poor maximum of the macro base station that UE receives in set N and micro-base station power is as CRE deviant.

Preferably, steps A comprises: in all UE of macro base station community that access macro base station σ, appoint and get UE i, judge whether UE i meets P _{macro (σ, i)}-P _{pico (j, i)}< Σ _{σ ' ∈ L, σ ' ≠ σ}p _{macro (σ ', i)}, if so, UE i is added in set M;

Wherein, P _{macro (σ, i)}represent the power that UE i receives from macro base station σ, P _{pico (j, i)}represent the power that UE i receives from micro-base station j, micro-base station j is micro-base station of micro-base station cell of accessing by CRE of UE i to be judged; P _{macro (σ ', i)}represent the interference power that UE i receives from macro base station σ ', L is macro base station set.

Preferably, step B comprises:

B1, according to P _{macro (σ, i)}-P _{pico (j, i)}value order from small to large from set select M one still untreated UE as current UE;

B2, judge whether the business demand of current UE can be met in ABS, if so, performs step B3, otherwise execution step B4;

B3, current UE is included into set N, and performs step B5;

B4, judge that whether current ABS number reaches the lower ABS maximum of current uplink/downlink configuration, if so, gets rid of current UE to gather outside N, and perform step B7; Otherwise execution step B5;

B5, current ABS number is added to 1, judge whether non-ABS resource can meet the business demand of micro-original UE in base station cell, if so, returns to step B2, otherwise, execution step B6;

B6, current ABS is subtracted to 1, current UE is got rid of outside set N, and performed step B7;

In B7, judgement set M, whether there is still untreated UE, if so, return to step B1, otherwise execution step C.

Preferably, the business demand that judges current UE described in step B2 whether can in ABS, be met into:

For current UE i, judge whether to meet if so, the business demand of current UE i can be met in ABS; Wherein, W _irepresent the business datum amount demand of UE i within the unit interval; eff _{pico (i)}represent that UE i accesses the transmitted bit number on each Physical Resource Block behind micro-base station cell; N _{pRB_ABS}the Physical Resource Block number that in the representation unit time, ABS can provide.

Preferably, described in step B5, judge that the business demand whether non-ABS resource can meet micro-original UE in base station cell comprises:

Judge whether to meet ${\mathrm{\&Sigma;}}_{i\&Element;I}\frac{w_i}{{\mathrm{eff}}_{\mathrm{pico}\left(i\right)}}\&le;N_{\mathrm{PRB}\_\mathrm{DL}}-N_{\mathrm{PRB}\_\mathrm{ABS}},$ If so, whether non-ABS resource can meet the business demand of micro-original UE in base station cell; Wherein, I is the original UE set in micro-base station cell, N _{pRB_DL}the PRB number of all descending sub frames in the representation unit time.

As can be seen from the above technical solutions, the situations such as the load level of reality Network Based, user distribution, base station spacing, transmitted power, CRE deviant and ABS are combined to configuration, the CRE deviant that the application proposes and ABS associated disposition method are guaranteeing the business transmission demand of each community, do not affect on the basis of ul transmissions, obtain high as far as possible network whole volume.Greatly simplify existing scheme and by traveling through various parameter combinations, obtained the process of best configuration; Solve existing scheme and only for certain special scenes, carried out emulation, can not be according to the problem of network condition dynamically-adjusting parameter configuration.

Accompanying drawing explanation

Fig. 1 is the typical scene schematic diagram in heterogeneous network;

CRE deviant and ABS associated disposition method flow chart that Fig. 2 provides for the embodiment of the present application.

Embodiment

With prior art scheme by the system emulation of special scenes, travel through various parameter combinations, with network down link whole volume maximum, turn to the method difference that unique target is carried out parameter configuration, the application has proposed a kind of load level of reality Network Based, user distribution, base station spacing, the situations such as transmitted power, the method of CRE deviant and ABS being combined flexibly to configuration, both the lifting network whole volume of having take is target, the ABS maximum number of the 3gpp agreement of take again regulation is configuration prerequisite, computing is simple, having solved existing scheme cannot configure according to network truth dynamically-adjusting parameter, operand is huge, and the problem of ignoring ul transmissions performance.

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

A kind of CRE deviant for heterogeneous network that the application provides and ABS associated disposition method scheme based on prerequisite be: all macro cell base station all configure identical ABS number; Macro cell base station only sends data in non-ABS subframe, and microcell base station can be in all subframe work, but only can obtain downlink transfer in ABS subframe by the UE that CRE is connected to microcell base station.

The basic principle that CRE deviant and ABS are combined to configuration that the embodiment of the present application provides comprises:

Principle one: UE accesses micro-base station cell higher Signal to Interference plus Noise Ratio (SINR) when obtaining than access macro base station community by CRE.

This principle can guarantee to obtain higher efficiency of transmission after this type of UE accesses micro-base station cell by CRE, the resource of macro base station community is discharged to guarantee that the better UE of other channel qualities is used simultaneously, thus the lifting that brings network capacity.

The SINR that UE i accesses behind micro-base station cell by CRE is:

${\mathrm{SINR}}_{\mathrm{pico}\left(i\right)}=P_{\mathrm{pico}(j,i)}-\underset{j^{\text{'}}\&Element;J,j^{\text{'}}\&NotEqual;j}{\mathrm{\&Sigma;}}{P}_{\mathrm{pico}(j^{\text{'}},i)}-\mathrm{\&eta;}---\left(1\right)$

Wherein, P _{pico (j, i)}represent the power that UE i receives from micro-base station j; P _{pico (j ', i)}represent the interference power that UE i receives from micro-base station j ', J is micro-collection of base stations; η represents noise power.Owing to adopting ABS mechanism, the UE that accesses micro-base station cell by CRE only receives in ABS subframe the data that micro-base station sends, and macro base station transmitted power not in ABS subframe, so this type of UE is only subject to the interference of other micro-base station powers.

The SINR when UE in CRE coverage accesses macro base station is:

${\mathrm{SINR}}_{\mathrm{macro}\left(i\right)}=P_{\mathrm{macro}(\mathrm{\&sigma;},i)}-\underset{{\mathrm{\&sigma;}}^{\text{'}}\&Element;L,{\mathrm{\&sigma;}}^{\text{'}}\&NotEqual;\mathrm{\&sigma;}}{\mathrm{\&Sigma;}}{P}_{\mathrm{macro}({\mathrm{\&sigma;}}^{\text{'}},i)}-\underset{j\&Element;J}{\mathrm{\&Sigma;}}{P}_{\mathrm{pico}(j,i)}-\mathrm{\&eta;}---\left(2\right)$

Wherein, P _{macro (σ, i)}represent the power that UE i receives from macro base station σ; P _{macro (σ ', i)}represent the interference power that UE i receives from macro base station σ ', L is macro base station set.

For the UE that guarantees to access micro-base station cell by CRE, obtain higher SINR, i.e. SINR during than access macro base station community _{pico (i)}> SINR _{macro (i)}, according to formula (1) and (2), need to meet:

Because the transmitted power of micro-base station is lower, and between micro-base station, distance is larger, and therefore micro-base station can be thought and equal 0(the interference of other micro-base station cells and macro base station community and ), (3) formula is converted into:

P _macro(σ,i)-P _pico(j,i)＜Σ _{σ‘∈L，σ‘≠σ}P _macro(σ',i) (4)

Meet the UE set of formula (4) for M, as the alternative UE that accesses micro-base station cell by CRE, gather.

Principle two: the business demand that accesses the UE of micro-base station cell by CRE can be met in ABS; In micro-base station cell, original UE(is by the i.e. UE of accessible micro-base station cell of CRE) business demand can in other descending sub frame except ABS, be met.

In fact this principle has stipulated the upper limit of CRE deviant, when ABS resource cannot meet the business demand within the scope of CRE, or when non-ABS resource cannot meet the business demand of micro-original UE in base station cell, no longer expand CRE scope, can guarantee like this business satisfaction of micro-base station cell.This principles and requirements meets following formula (5) and (6) simultaneously:

${\mathrm{\&Sigma;}}_{i\&Element;N}\frac{w_i}{{\mathrm{eff}}_{\mathrm{pico}\left(i\right)}}\&le;N_{\mathrm{PRB}\_\mathrm{ABS}}---\left(5\right)$

${\mathrm{\&Sigma;}}_{i\&Element;I}\frac{w_i}{{\mathrm{eff}}_{\mathrm{pico}\left(i\right)}}\&le;N_{\mathrm{PRB}\_\mathrm{DL}}-N_{\mathrm{PRB}\_\mathrm{ABS}}---\left(6\right)$

Wherein, W _irepresent the business datum amount demand of UE i within the unit interval; eff _{pico (i)}represent that UE i accesses the efficiency of transmission behind micro-base station cell, i.e. transmitted bit number on each Physical Resource Block (Physical Resource Block, PRB); N _{pRB_ABS}the PRB number that in the representation unit time, ABS can provide; N _{pRB_DL}the PRB number of all descending sub frames in the representation unit time; I is the original UE set in micro-base station cell; UE by set in M is according to P _{macro (σ, i)}-P _{pico (j, i)}value order from small to large substitution one by one (5) judges, the UE that meets (5) is included into set N.

Along with number of users increases, for meeting formula (5), ABS number increases progressively gradually since 1, but simultaneously for meeting formula (6), ABS can not infinitely increase.In addition, ABS can't surpass the ABS maximum under the uplink/downlink configuration (UL/DL configuration) of 3GPP agreement regulation of current employing, the problem that the ABS that has avoided may occurring in existing scheme too much causes uplink mandate to send.

Finally because the UE in set M all completes the judgement of formula (5), or because ABS increases, cause formula (6) not meet, or ABS is while being increased to the maximum of 3GPP agreement regulation, the UE in Stopping set N adds.Stop the front ABS value that meets formula (6) and 3GPP agreement regulation as the ABS number Configuration Values of recommending.

CRE deviant is by gathering macro base station and the poor decision of micro-base station power that in N, UE receives, that is:

CREbias＝max _i∈N{P _macro(σ,i)-P _pico(j,i)} (7)

Adopt above-mentioned computational process, can obtain according to factors such as the distribution situation of user in HetNet, traffic carrying capacity, base-station transmitting-power, interference levels the best configuration of CRE deviant and ABS.

The CRE deviant that the embodiment of the present application provides and ABS associated disposition method flow process as shown in Figure 2, comprise the steps:

Step 201: the principle that accesses micro-base station cell higher Signal to Interference plus Noise Ratio when obtaining than access macro base station community by CRE based on UE, in all UE of access macro base station community, determine the alternative UE set M that accesses micro-base station cell by CRE.

In the embodiment of the present application, this step can realize in the following way:

In all UE of macro base station community that access macro base station σ, appoint and get UE i, judge whether UE i meets P _{macro (σ, i)}-P _{pico (j, i)}< Σ _{σ ' ∈ L, σ ' ≠ σ}p _{macro (σ ', i)}, if so, UE i is added in set M; Wherein, P _{macro (σ, i)}represent the power that UE i receives from macro base station σ, P _{pico (j, i)}represent the power that UE i receives from micro-base station j, micro-base station j is micro-base station of micro-base station cell of accessing by CRE of UE i to be judged; P _{macro (σ ', i)}represent the interference power that UE i receives from macro base station σ ', L is macro base station set.

Step 202: according to P _{macro (σ, i)}-P _{pico (j, i)}value order from small to large from set select M one still untreated UE as current UE.

Step 203: whether the business demand that judges current UE can be met in ABS, if so, performs step 204, otherwise execution step 205.

In the present embodiment, whether the business demand that judges current UE can be met to be reduced to and judge whether to meet formula (5) in ABS.

Step 204: current UE is included into set N, and performs step 206.

Step 205: judge that whether current ABS number reaches the ABS maximum under current uplink/downlink configuration, if so, gets rid of current UE outside set N, and performs step 208.Otherwise execution step 206.

Step 206: current ABS number is added to 1, judge whether non-ABS resource can meet the business demand of micro-original UE in base station cell, if so, returns to step 203, otherwise, execution step 207.

In the present embodiment, judge business demand that whether non-ABS resource can meet micro-original UE in base station cell can be reduced to judge whether to meet formula (6).

Step 207: current ABS is subtracted to 1, current UE is got rid of outside set N, and performed step 208.

Step 208: in judgement set M, whether there is still untreated UE, if so, return to step 202, otherwise execution step 209.

Step 209: using current ABS number as the ABS number Configuration Values of recommending, the poor maximum of the macro base station that UE receives in set N and micro-base station power is as CRE deviant, i.e. CRE bias=max _{i ∈ N}{ P _{macro (σ, i)}-P _{pico (j, i)}.Then process ends.

The CRE deviant that the application proposes and ABS associated disposition method, guaranteeing not affect the business transmission demand of each community on the basis of ul transmissions, obtain high as far as possible network whole volume.Greatly simplify existing scheme and by traveling through various parameter combinations, obtained the process of best configuration; Solve existing scheme and only for certain special scenes, carried out emulation, can not be according to the problem of network condition dynamically-adjusting parameter configuration.

The foregoing is only the application's preferred embodiment; not in order to limit the application's protection range; all within the spirit and principle of present techniques scheme, any modification of making, be equal to replacement, improvement etc., within all should being included in the scope of the application's protection.

Claims (5)

1. for the cell coverage area expansion CRE deviant of heterogeneous network and a blank subframe ABS associated disposition method almost, it is characterized in that, comprising:

A, the principle that accesses micro-base station cell higher Signal to Interference plus Noise Ratio when obtaining than access macro base station community by CRE based on user equipment (UE), in all UE of access macro base station community, determine the alternative UE set M that accesses micro-base station cell by CRE;

B, from set, choose UE M and form set N, and current ABS number is adjusted, following condition is met simultaneously: the UE in described set N is accessed micro-base station cell and can in ABS, be met business demand by CRE, in micro-base station cell, the business demand of original UE can be met in other descending sub frame except ABS, and current ABS number is no more than the ABS maximum under the uplink/downlink configuration of current employing;

C, using current ABS number as the ABS number Configuration Values of recommending, the poor maximum of the macro base station that UE receives in set N and micro-base station power is as CRE deviant.

2. method according to claim 1, is characterized in that, steps A comprises: in all UE of macro base station community that access macro base station σ, appoint and get UE i, judge whether UE i meets P _{macro (σ, i)}-P _{pico (j, i)}< Σ _{σ ' ∈ L, σ ' ≠ σ}p _{macro (σ ', i)}, if so, UE i is added in set M; Wherein, P _{macro (σ, i)}represent the power that UE i receives from macro base station σ, P _{pico (j, i}) represent that the power that UE i receives from micro-base station j, micro-base station j are micro-base station of micro-base station cell of accessing by CRE of UE i to be judged; P _{macro (σ ', i)}represent the interference power that UE i receives from macro base station σ ', L is macro base station set.

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

B1, according to P _{macro (σ, i)}-P _{pico (j, i)}value order from small to large from set select M one still untreated UE as current UE;

B2, judge whether the business demand of current UE can be met in ABS, if so, performs step B3, otherwise execution step B4;

B3, current UE is included into set N, and performs step B5;

B4, judge that whether current ABS number reaches the lower ABS maximum of current uplink/downlink configuration, if so, gets rid of current UE to gather outside N, and perform step B7; Otherwise execution step B5;

B5, current ABS number is added to 1, judge whether non-ABS resource can meet the business demand of micro-original UE in base station cell, if so, returns to step B2, otherwise, execution step B6;

B6, current ABS is subtracted to 1, current UE is got rid of outside set N, and performed step B7;

In B7, judgement set M, whether there is still untreated UE, if so, return to step B1, otherwise execution step C.

4. method according to claim 3, is characterized in that, the business demand that judges current UE described in step B2 whether can in ABS, be met into:

For current UE i, judge whether to meet if so, the business demand of current UE i can be met in ABS; Wherein, W _irepresent the business datum amount demand of UE i within the unit interval; eff _{pico (i)}represent that UE i accesses the transmitted bit number on each Physical Resource Block behind micro-base station cell; N _{pRB_ABS}the Physical Resource Block number that in the representation unit time, ABS can provide.

5. method according to claim 3, is characterized in that, judges that the business demand whether non-ABS resource can meet micro-original UE in base station cell comprises described in step B5:

Judge whether to meet ${\mathrm{\&Sigma;}}_{i\&Element;I}\frac{w_i}{{\mathrm{eff}}_{\mathrm{pico}\left(i\right)}}\&le;N_{\mathrm{PRB}\_\mathrm{DL}}-N_{\mathrm{PRB}\_\mathrm{ABS}},$ If so, whether non-ABS resource can meet the business demand of micro-original UE in base station cell; Wherein, I is the original UE set in micro-base station cell, N _{pRB_DL}the PRB number of all descending sub frames in the representation unit time.