CN102883328A - Method and device for adjusting range expansion offset value of micro cell - Google Patents

Abstract

The invention discloses a method and a device for adjusting a range expansion offset value of a micro cell in an environment in which at least one micro cell is arranged in a macro cell. The method comprises the following steps that: under the condition that the range expansion offset value is required to be adjusted, a base station of each micro cell determines a candidate range expansion offset value set, wherein under each range expansion offset value except for a zero offset value in the candidate range expansion offset value set, a signal to interference ratio of each piece of user equipment related to the micro cell according to a first rule is not smaller than a first threshold value; and according to a second rule, one range expansion offset value is selected from the candidate range expansion offset value set and is used as a new range expansion offset value of the micro cell. According to the method and the device, effective inter cell interference coordination (ICIC) can be implemented, and giant or even insufferable expense is avoided.

Description

Adjust the method and apparatus of the scope expansion bias of Microcell

Technical field

The present invention relates to the communications field, more specifically, the present invention relates to adjust the method and apparatus of the scope expansion bias of Microcell.

Background technology

When having disposed a plurality of Microcell that can openly access in macrocell, some subscriber equipmenies can be served by Microcell, thereby alleviate the burden of macrocell, realize load balance.Wherein macrocell for example is basic wireless cellular network residential quarter among LTE-A, 3G, the GSM, and Microcell is such as being pico residential quarter, femto residential quarter etc.

In the LTE-A system, base station (eNB) can send reference symbol, and be mutually orthogonal between the reference symbol that wherein each base station sends.Each subscriber equipment can be measured the power of the reference symbol that receives from its base station on every side.And, if subscriber equipment is in connection mode, the reference symbol received power of measuring can be reported to its serving BS.

For any user equipment (UE) _j, use

Represent the set of its peripheral base station, if UE _jBe in connection mode, and when considering to switch, Also comprise UE _jServing BS.And, use RSRP _IjExpression UE _jThe power of the reference symbol that receives from base station i of measuring, the so conventional cell association criterion based on the reference symbol received power of measuring can be expressed as follows:

$\mathrm{Cell}\_{\mathrm{ID}}_{\mathrm{serving}}=\arg {\max }_{\left\{i\right\}}\left\{{\mathrm{RSRP}}_{\mathrm{ij}}\right\},i\∈{\mathrm{\Λ}}_{\mathrm{surr}}^{\left(j\right)}---\left(1\right)$

The implication of above-mentioned criterion is UE _jProminent that base station of the reference symbol that receives from its peripheral base station of its measurement will be associated with.

In the situation that macrocell-picocell deployment, if still use such as given cell association criterion in (1), than Microcell, will have more subscriber equipment to be associated with macrocell so, reason is that the transmitted power of macro cell base station is much larger than the transmitted power of microcell base station.In this case, the available resources of Microcell are not fully utilized, and in macrocell, very fierce for the competition meeting of available resources.For the potential load balance function that is provided by Microcell more effectively is provided, for the deployment scenario of macrocell-Microcell, for any UE _j, use following cell association criterion:

$\mathrm{Cell}\_{\mathrm{ID}}_{\mathrm{serving}}=\arg {\max }_{\left\{i\right\}}\{{\mathrm{RSRP}}_{\mathrm{ij}}+{\mathrm{bias}}_i\},i\∈{\mathrm{\Λ}}_{\mathrm{surr}}^{\left(j\right)}---\left(2\right)$

The implication of above-mentioned criterion is UE _jThe power of the reference symbol that receives from its peripheral base station of its measurement and the bias (bias of peripheral base station will be associated with _i) with that base station (macro cell base station or microcell base station) of maximum.

In above-mentioned equation (2), for macrocell, bias is 0, and for each Microcell, bias is a nonnegative value, thereby more subscriber equipment can be arranged by the Microcell service.Because the use of bias is equivalent to give the ability of the scope of Microcell extending user device association, so this process is called the scope expansion (RE) of Microcell, and above-mentioned bias also is called scope expansion bias.

For system, need to correctly design Microcell scope expansion bias, realizing good load balance, and do not cause additionally owing to disturbing the problem that produces, the subscriber equipment of the Microcell that the scope that for example is associated with is expanded is experiencing low signal interference ratio (SIR).

Current, in LTE version-10 (Rel-10), recommend in the specific mode in residential quarter scope expansion bias to be set.And, consider the simplicity of realization, in LTE Rel-10, recommend for all Microcells of disposing in the macrocell, identical scope expansion bias is set.

Based on a large amount of assessment reports, can draw following conclusion:

Situation for the scope expansion of not supporting Microcell, for descending (DL) control channel (CCH), there is not problem of inter-cell interference, and for the DL data channel, presence of intercell interference cancellation (ICIC) scheme of reusing Rel-8/9 just can solve problem of inter-cell interference well.

Yet, for the specific scope expansion bias setting in use residential quarter and for each Microcell, use the situation of the current standard recommendation of identical scope expansion bias, observe increase scope expansion bias and can realize better load balance, but can make the lower SIR of subscriber equipment experience that is associated with corresponding Microcell, particularly for the subscriber equipment that is in the Microcell edge, the risk that therefore can cause DL CCH problem of inter-cell interference to occur increases, and finally causes radio jink failure.

Propose a kind of time division multiplexing (TDM) ICIC technology, be called almost blank subframe (ABS) technology, solved DL CCH problem of inter-cell interference.In the ABS technology, macro cell base station as interference source, be configured to the subframe of ABS at some, in physics DLCCH (PDCCH), do not carry out transfer of data, and only transmit the specific reference symbol in residential quarter (CRS) and possibly, at other primary channel, for example carry out transfer of data on the Physical Broadcast Channel.Obviously, in being configured to the subframe of ABS, do not carry out transfer of data at Physical Downlink Shared Channel (PDSCH), namely do not carry out transfer of data at data channel.In the implementation procedure of ABS technology, the interfere information of time domain must be via the communication link between certain base station, and for example the back haul link of X2-type exchanges between neighbor cell.

Yet the ABS technology still suffers the interference problem of " CRS is to control signal ", even reason is that macro cell base station should keep transmitting CRS in blank subframe almost.More importantly, the inherent shortcoming of this TDM ICIC technology is to have reduced time-domain resource available in the macrocell, thereby causes the throughput performance of subscriber equipment in the macrocell to reduce.

Therefore, importantly be or for the plan of establishment of the scope of current consideration expansion bias, design more effective DL CCH ICIC technology, or the plan of establishment of the scope of design improvement expansion bias, the load balance that it can be realized, and can realize good DL CCH ICIC effect.

Summary of the invention

According to a first aspect of the invention, proposed a kind ofly to be deployed with in the environment of at least one Microcell in a macrocell, the method for the scope expansion bias of a described Microcell is adjusted in a base station of a Microcell, comprises step:

Adjust in the situation that determine to carry out scope expansion bias, the set of candidate's scope expansion bias is determined in the base station of a described Microcell, wherein in the set of candidate's scope expansion bias under each scope expansion bias except zero offset value, be associated with the signal interference ratio that each subscriber equipment of a described Microcell experiences according to the first criterion and be not less than first threshold;

And according to the second criterion, from the set of described candidate's scope expansion bias, select a scope expansion bias as the new scope expansion bias of a described Microcell.

According to a second aspect of the invention, proposed a kind ofly for being deployed with in the environment of at least one Microcell at a macrocell, adjusted the device of the scope expansion bias of a Microcell, having comprised:

Determining unit, be used in the situation that determine to carry out the adjustment of scope expansion bias, determine the set of candidate's scope expansion bias, wherein in the set of candidate's scope expansion bias under each scope expansion bias except zero offset value, be associated with the signal interference ratio that each subscriber equipment of a described Microcell experiences according to the first criterion and be not less than first threshold; And

Selected cell is used for according to the second criterion, selects a scope expansion bias as the new scope expansion bias of a described Microcell from the set of described candidate's scope expansion bias.

According to the embodiment of the present invention, can realize effective ICIC, do not have huge or even not endurable expense.

Description of drawings

By below in conjunction with the description of the drawings, and along with understanding more comprehensively of the present invention, other purposes of the present invention and effect will become more clear and easy to understand, wherein:

Fig. 1 shows the environment 100 that the present invention can realize therein;

Fig. 2 shows the flow chart of method of adjusting the scope expansion bias of a described Microcell according to a base station of a Microcell of an embodiment of the invention;

The flow chart of method of the scope expansion bias of a described Microcell is adjusted in the base station that Fig. 3 shows a Microcell according to another implementation of the invention;

Fig. 4 shows the block diagram according to the device of the scope expansion bias that is used for a Microcell of adjustment of an embodiment of the invention.

In all above-mentioned accompanying drawings, identical label represents to have identical, similar or corresponding feature or function.

Embodiment

The present invention considers the following fact, for near the good scope expansion bias of the Microcell of macrocell with should be different for the good scope expansion bias away from the Microcell of macrocell, and the good scope expansion bias of a Microcell can change in time.

Therefore, basic thought of the present invention is the scope expansion bias of adaptive adjustment Microcell, to adapt to the variation of wireless environment.

Suppose that each Microcell has a plurality of scope expansion biases to select, if consider to use the overall situation/centralized prioritization scheme, so whenever needs carry out the adjustment of scope expansion bias to a Microcell, when adapting to the variation of wireless environment, the global optimization scheme need to reset the scope expansion bias of all Microcells, to realize the performance of effective ICIC and global optimum.The result who does like this is, will be huge or even not endurable based on cooperation expense and the computation complexity of back haul link, particularly under the number of the Microcell that dispose in a macrocell is not very little situation.

Therefore, in execution mode as described below of the present invention, pay close attention to distributed schemes.That is to say, adjust adaptively its scope expansion bias by each microcell base station oneself, to adapt to the variation of wireless environment.According to the embodiment of the present invention, can realize effective ICIC, and not have huge or even not endurable expense.

Fig. 1 shows the environment 100 that the present invention can implement therein.

As shown in Figure 1, this environment 100 comprises the first base station 110 corresponding to the first residential quarter, corresponding to the second base station 120 and a plurality of subscriber equipment 130-1,130-2,130-3,130-4,130-5 and the 130-6 of the second residential quarter.

The first base station 110 provides the first coverage 110-a, and the second base station 120 provides the second coverage 120-a.

Subscriber equipment can be in environment 100 interior movements, and can enter or withdraw from the first and second coverage 110-a, 120-a.Therefore, subscriber equipment communicates by Radio Link 140 and the first base station 110.Perhaps, subscriber equipment communicates by Radio Link 150 and the second base station 120.In addition, communicate by back haul link 160 between the first base station 110 and the second base station 120.Back haul link 160 can be wired, also can be wireless.

Here, suppose that the first base station 110 is macro cell base station, the second base station 120 is microcell base stations, and wherein macro cell base station is such as being basic wireless cellular network base station among LTE-A, 3G, the GSM etc., and microcell base station for example is that pico base station, femto base station, via node or remote radio frequency are first-class.In description of the invention, base station and residential quarter are to concern one to one.Namely a residential quarter only has a base station, and a residential quarter is only served in a base station.

As shown in Figure 1, the first coverage 110-a comprises the second coverage 120-a fully.Certainly, those skilled in the art will appreciate that the first coverage 110-a can partly comprise the second coverage 120-a.Even first coverage 110-a and the second coverage 120-a do not intersect.

Here, for simplicity and for the purpose of clear, in Fig. 1, only show a Microcell and 6 subscriber equipmenies, it will be understood by those of skill in the art that number that the present invention is applicable to be deployed with in the macrocell a plurality of Microcells and subscriber equipment is greater or less than 6 scene.

Based on the assessment result of emulation or actual test, can set in advance M can be for the scope expansion bias of Microcell selection.In the following description as an example, such as, for each Microcell, in following M=6 the scope expansion bias can be set, i.e. bias ₁=0dB (i.e. forbidding scope expansion), bias ₂=2dB, bias ₃=4dB, bias ₄=6dB, bias ₅=8dB, bias ₆=10dB.

In addition, when initialization, it is identical experience optimal value that each microcell base station can arrange scope expansion bias, median for example, and 4dB, perhaps each microcell base station can scope be expanded bias and is set to 0dB.

In following description, system bandwidth is expressed as B Hz, and the cell identifier of macrocell is expressed as 0, and the cell identifier that is positioned at K Microcell of macrocell is expressed as 1,2 ..., K.Each residential quarter comprises macrocell and Microcell, all send mutually between the reference symbol of quadrature.Each user equipment (UE) _jThe power of the reference symbol that measurement receives from its base station in service sector and neighbor cell base station, and measured value reported to its serving BS.

For any UE _j, measurement from base station k (k ∈ 0,1 ..., the wattmeter of the reference symbol that K}) receives is shown X _Kj(watt).

From the viewpoint of base station k, for any one UE _j,

Expression produces { X _Ij, the set of the base station of the reference symbol received power among i ≠ k}.

For outstanding basic thought of the present invention, ignore in the following description the impact of noise.

In following description of the present invention, only pay close attention to connection mode.Because for idle pulley, the expansion of support scope can only obtain very little load balance advantage, and reason is the transmission that does not have data business volume in idle pulley.

Some subscriber equipmenies at Microcell experience in the situation of unacceptable interference (based on the report from these subscriber equipmenies), this microcell base station determines to carry out the adjustment of scope expansion bias so, adjust to another less value so that its scope is expanded bias, thereby so that these experience the user device association of unacceptable interference to other residential quarter (comprising other Microcells or macrocell).In the present invention, this scene is called " scope expansion bias reduces " scene.

Subscriber equipment in Microcell worked under the current scope expansion bias one predetermined time section situation under, that is to say, in this section, there is not subscriber equipment owing to experiencing from the interference of macro cell base station and/or other adjacent microcell base stations in the situation of low SIR predetermined time, this microcell base station determines to carry out the adjustment of scope expansion bias so, so that its scope expansion bias is adjusted to another larger value, to obtain better load balance.In the present invention, this scene is called " scope expansion bias may increase " scene.

The below will describe respectively this two kinds of scenes.

" scope expansion bias may increase " scene is at first described.

Fig. 2 shows the flow chart of method of adjusting the scope expansion bias of a described Microcell according to a base station of a Microcell of an embodiment of the invention.

The flow chart of method shown in Figure 2 is corresponding to " scope expansion bias may increase " scene.

As shown in Figure 2, described method 200 comprises step S210, the information of the power of the reference symbol that receives from its peripheral base station that the base station of a Microcell is measured about the subscriber equipment of the base station of described other residential quarters to the base station requests of other residential quarters; Step S220, the base station of a described Microcell receives the information of the power of the reference symbol that receives from its peripheral base station of measuring about the subscriber equipment of the base station of described other residential quarters from the base station of described other residential quarters; Step S230, the set of candidate's scope expansion bias is determined in the base station of a described Microcell, wherein each scope is expanded under bias in the set of candidate's scope expansion bias, be associated with the signal interference ratio that each subscriber equipment of a described Microcell experiences according to the first criterion and be not less than first threshold and carried out subscriber equipment after the association of residential quarter according to the first criterion, the downlink throughput capacity of system is not less than the downlink throughput capacity of the system under current scope expansion bias; And step S240, according to the second criterion, from the set of described candidate's scope expansion bias, select a scope expansion bias as the new scope expansion bias of a described Microcell.

Described first threshold can be the target signal interference ratio of down control channel.

Described first threshold also can be the maximum in the minimum value of the target signal interference ratio of the target signal interference ratio of down control channel and downstream data channel, and namely first threshold is SIR wherein _{CCH target}[dB] is the target signal interference ratio of down control channel, and it is a system parameters with set-point,

Minimum value for the target signal interference ratio of downstream data channel, for different Modulation and Coding Scheme (MCS), the target signal interference ratio of downstream data channel has different values, and each base station can be known the target signal interference ratio for the different downstream data channel of different Modulation and Coding Scheme (MCS) in advance.

Described the first criterion can be expanded that base station bias and maximum with the scope of peripheral base station for the power that aforesaid each subscriber equipment will be associated with the reference symbol that receives from its peripheral base station of its measurement.

Described the second criterion can have been carried out subscriber equipment after the association of residential quarter for selection from the set of described candidate's scope expansion bias makes according to the first criterion, and that scope expansion bias of the downlink throughput capacity maximum of system is as the new scope expansion bias of a described Microcell.

Usually, along with the increase of scope expansion bias the increase of the number of the subscriber equipment that is associated with Microcell (namely along with), the downlink throughput capacity of system can increase first, can descend after increasing to certain value.That is to say and to exist one to make the downlink throughput capacity of system be turned the flex point scope expansion bias that falls by liter.Certainly, because a M that sets in advance (M=6 in the example of this paper) can be based on for the scope expansion bias that Microcell is selected a large amount of system-level emulation or actual test and appraisal gained, it can not comprise the excessive scope expansion bias more than or equal to the flex point value usually.So, those skilled in the art will appreciate that described the second criterion also can be for selecting to make that maximum scope expansion bias of the number of user equipment that is associated with a described Microcell as the new scope expansion bias of a described Microcell from the set of described candidate's scope expansion bias.

If the scope of microcell base station k expansion bias is from bias _mBecome bias _n, bias wherein _n＞bias _mUsually, the number of the subscriber equipment that is associated with this microcell base station k can increase, that is to say, have some subscriber equipmenies and change into and be associated with this microcell base station k from being associated with macro cell base station or other microcell base stations, and might some subscriber equipmenies that newly are associated with this microcell base station k can experience severe jamming from other base-station transmissions, thereby its signal interference ratio is lower, even might be lower than first threshold, this original intention with adjusting range expansion bias contradicts.

Therefore, in this scene, when can definite scope expansion bias become candidate's scope expansion bias of the new scope expansion bias that can be used as a Microcell, need to be bias for expanding bias by adjustment microcell base station k scope _nAfter be associated with each UE of Microcell k _j, determine whether its signal interference ratio is not less than first threshold, namely

$10\mathrm{lo}{g}_{10}(X_{\mathrm{kj}}/{\mathrm{\Σ}}_{i\∈{\mathrm{\Λ}}_j^{\left(k\right)}}{X}_{\mathrm{ij}})\≥{\mathrm{SIR}}_{\mathrm{CCHt}\arg \mathrm{et}}---\left(3\right).$

Can use at step S220, the information of the power of the reference symbol that receives from its peripheral base station that the subscriber equipment about the base station of other residential quarters that the base station of a Microcell receives from the base station of other residential quarters is measured carries out above-mentionedly determining.

For simplicity, in description of the invention, only consider to expand bias from bias in the scope of microcell base station _mBecome bias _n, bias wherein _n＞bias _mThe time, subscriber equipment changes the situation that is associated with this microcell base station k into from being associated with macro cell base station, and does not consider that subscriber equipment changes the situation that is associated with this microcell base station k into from being associated with other microcell base stations.

In addition, if the scope of a microcell base station k is expanded bias from bias _mBecome bias _n, bias wherein _n＞bias _m, the throughput of the system after the adjustment may be lower than the throughput of the system before adjusting, and this also contradicts with the original intention of adjusting range expansion bias.Therefore, when determining that can a scope expansion bias become candidate's scope expansion bias of the new scope expansion bias that can be used as a Microcell, also need to determine to have carried out subscriber equipment after the association of residential quarter according to the first criterion, whether the downlink throughput capacity of system is not less than the downlink throughput capacity of the system under current scope expansion bias.

If the current scope expansion bias that uses of microcell base station k is bias _m, m ∈ 1 ..., and 6}, the set and the number that are associated with the subscriber equipment of described microcell base station k are expressed as respectively With

And current set and the number that is associated with the subscriber equipment of macro cell base station is expressed as respectively

With Microcell base station k can estimate respectively the downlink throughput capacity of macrocell so

Downlink throughput capacity with Microcell k

For as follows:

$c_0^{\left({\mathrm{bias}}_m\right)}=\frac{B}{N_0^{\left({\mathrm{bias}}_m\right)}}\·\underset{{j\∈\mathrm{UESet}}_0^{\left({\mathrm{bias}}_m\right)}}{\mathrm{\Σ}}{\log }_2(1+\frac{x_{0j}}{\underset{i\∈{\mathrm{\Λ}}_j^{\left(0\right)}}{\mathrm{\Σ}}{X}_{\mathrm{ij}}})---\left(4.1\right)$

$c_k^{\left({\mathrm{bias}}_m\right)}=\frac{B}{N_k^{\left({\mathrm{bias}}_m\right)}}\·\underset{{j\∈\mathrm{UESet}}_k^{\left({\mathrm{bias}}_m\right)}}{\mathrm{\Σ}}{\log }_2(1+\frac{x_{\mathrm{kj}}}{\underset{i\∈{\mathrm{\Λ}}_j^{\left(k\right)}}{\mathrm{\Σ}}{X}_{\mathrm{ij}}})---\left(4.2\right)$

In addition, utilize

In the available information of power of the reference symbol that receives from its peripheral base station measured of each subscriber equipment, for each n, wherein n ∈ 1 ..., 6}, n ≠ m and bias _n＞bias _m, microcell base station k utilizes the cell association criterion based on RSRP+Bias in the above-mentioned equation (2), estimates to change at scope expansion bias to be made as bias _nSituation under, be associated with the set of the subscriber equipment of macrocell

Set with the subscriber equipment that is associated with Microcell k

And, according to what estimate

With

Estimation is associated with the number of the subscriber equipment of macrocell in the case

Number with the subscriber equipment that is associated with Microcell k

Then, utilize in equation 4.1 and 4.2 and similarly calculate, microcell base station k can estimate

With

Then, whether microcell base station k determines in the situation that inequality (3) is satisfied, set up such as lower inequality:

$c_0^{\left({\mathrm{bias}}_n\right)}+c_k^{\left({\mathrm{bias}}_n\right)}\≥c_0^{\left({\mathrm{bias}}_m\right)}+c_k^{\left({\mathrm{bias}}_m\right)}---\left(5\right)$

If set up, microcell base station k is with bias so _nPut into candidate's scope expansion bias set omega.Otherwise not with bias _nPut in candidate's scope expansion bias set omega.

In order not make candidate's scope expansion bias set omega for empty, the scope expansion bias of current use can be placed in the set omega, wherein the scope of current use expansion bias satisfies above-mentioned inequality (3) and (5) natively.

Then, can be according to following expression:

${\arg \max }_{\left\{n\right\}}\{c_0^{\left({\mathrm{bias}}_n\right)}+c_k^{\left({\mathrm{bias}}_n\right)}\},{\mathrm{bias}}_n\∈\mathrm{\Ω}$

From the set of described candidate's scope expansion bias, select a scope expansion bias as the new scope expansion bias of a described Microcell.

That is to say, select to make according to the first criterion to have carried out subscriber equipment after the association of residential quarter from the set of described candidate's scope expansion bias, that scope expansion bias of the downlink throughput capacity maximum of system is as the new scope expansion bias of a described Microcell.

The flow chart of method of the scope expansion bias of a described Microcell is adjusted in the base station that Fig. 3 shows a Microcell according to another implementation of the invention.

The flow chart of method shown in Figure 3 is corresponding to " scope expansion bias reduces " scene.

Because under " scope expansion bias reduces " scene, the scope expansion bias of a microcell base station k will be from bias _mBecome bias _n, bias wherein _n＜bias _mAnd usually, the number of the subscriber equipment that is associated with this microcell base station k can reduce, that is to say, have some subscriber equipmenies and change into and be associated with macro cell base station or other microcell base stations from being associated with this microcell base station k, the throughput of the system after causing adjusting can be lower than the throughput of the system before adjusting.Therefore, when determining that can a scope expansion bias become candidate's scope expansion bias of the new scope expansion bias that can be used as a Microcell, carried out subscriber equipment after the association of residential quarter according to the first criterion, the downlink throughput capacity whether downlink throughput capacity of system is not less than the system under current scope expansion bias there is no need, and only need to be associated with the signal interference ratio that each subscriber equipment of a described Microcell experiences according to the first criterion and be not less than first threshold (except zero offset value).

Therefore, compare with flow chart shown in Figure 2, flow chart shown in Figure 3 does not need to comprise step S210, the information of the power of the reference symbol that receives from its peripheral base station that the base station of a Microcell is measured about the subscriber equipment of the base station of described other residential quarters to the base station requests of other residential quarters; Step S220, the base station of a described Microcell receives the information of the power of the reference symbol that receives from its peripheral base station of measuring about the subscriber equipment of the base station of described other residential quarters from the base station of described other residential quarters.

That is to say, flow chart 300 shown in Figure 3 comprises step S310, the set of candidate's scope expansion bias is determined in the base station of a described Microcell, wherein in the set of candidate's scope expansion bias under each scope expansion bias except zero offset value, be associated with the signal interference ratio that each subscriber equipment of a described Microcell experiences according to the first criterion and be not less than first threshold; And step S320, according to the second criterion, from the set of described candidate's scope expansion bias, select a scope expansion bias as the new scope expansion bias of a described Microcell.

Because might be for all bias _n＜bias _m(bias _n≠ 0), even the scope of a microcell base station k is expanded bias from bias _mBecome bias _n, can not satisfy being associated with the signal interference ratio that each subscriber equipment of a described Microcell experiences according to the first criterion and being not less than this condition of first threshold, in order to make the set of candidate's scope expansion bias for empty, work as bias _n=0 o'clock, do not need to satisfy and be associated with the signal interference ratio that each subscriber equipment of a described Microcell experiences according to the first criterion and be not less than this condition of first threshold.

Note, as previously mentioned, be set at 0 o'clock at scope expansion bias (when namely not supporting or forbidding the scope expansion of Microcell), for down control channel, there is not problem of inter-cell interference, and for downstream data channel, the ICIC scheme of reusing Rel-8/9 just can solve problem of inter-cell interference well.

Certainly, if described the second criterion is for selecting to make according to the first criterion to have carried out subscriber equipment after the association of residential quarter from the set of described candidate's scope expansion bias, that scope expansion bias of the downlink throughput capacity maximum of system is as the new scope expansion bias of a described Microcell, the step S210 of the flow chart that flow chart so as shown in Figure 3 also needs to comprise that step is shown in Figure 2, the information of the power of the reference symbol that receives from its peripheral base station that the base station of a Microcell is measured about the subscriber equipment of the base station of described other residential quarters to the base station requests of other residential quarters; Step S220, the base station of a described Microcell receives the information of the power of the reference symbol that receives from its peripheral base station of measuring about the subscriber equipment of the base station of described other residential quarters from the base station of described other residential quarters, reason is as mentioned above, and these information need to be used when the downlink throughput capacity of computing system.

Fig. 4 shows the block diagram according to the device of the scope expansion bias that is used for a Microcell of adjustment of an embodiment of the invention.

As shown in Figure 4, this device 400 comprises determining unit 410, be used in the situation that determine to carry out the adjustment of scope expansion bias, determine the set of candidate's scope expansion bias, wherein in the set of candidate's scope expansion bias under each scope expansion bias except zero offset value, be associated with the signal interference ratio that each subscriber equipment of a described Microcell experiences according to the first criterion and be not less than first threshold; And selected cell 420, be used for according to the second criterion, from the set of described candidate's scope expansion bias, select a scope expansion bias as the new scope expansion bias of a described Microcell.

Wherein said first threshold can be the target signal interference ratio of down control channel.

Wherein said first threshold also can be the maximum in the minimum value of the target signal interference ratio of the target signal interference ratio of down control channel and downstream data channel.

Wherein said the first criterion is expanded that base station bias and maximum for the power that each subscriber equipment will be associated with the reference symbol that receives from its peripheral base station of its measurement with the scope of peripheral base station.

Wherein, described device can also comprise request unit 402, is used for the information of the power of the reference symbol that receives from its peripheral base station from the subscriber equipment of the base station of described other residential quarters to the base station requests of other residential quarters that measure about; And receiving element 404, be used for receiving from the base station of described other residential quarters the information of the power of the reference symbol that receives from its peripheral base station of measuring about the subscriber equipment of the base station of described other residential quarters.

Wherein said the second criterion can have been carried out subscriber equipment after the association of residential quarter for selection from the set of described candidate's scope expansion bias makes according to the first criterion, and that scope expansion bias of the downlink throughput capacity maximum of system is as the new scope expansion bias of a described Microcell.

Wherein for " scope expansion bias may increase " scene, under each scope expansion bias in the set of candidate's scope expansion bias, carried out subscriber equipment after the association of residential quarter according to the first criterion, the downlink throughput capacity of system need to be not less than the downlink throughput capacity of the system under current scope expansion bias.

Wherein said other residential quarters are macrocell.

Should be noted that for the present invention is more readily understood, top description has been omitted to be known for a person skilled in the art and may to be essential more specifically some ins and outs for realization of the present invention.

Those skilled in the art it is also understood that and the invention is not restricted to step described above, and the present invention also comprises combination that step described above is carried out, order conversion etc.Final scope of the present invention is defined by the appended claims.

Therefore; selecting and describing execution mode is in order to explain better principle of the present invention and practical application thereof; and those of ordinary skills are understood, under the prerequisite that does not break away from essence of the present invention, all modifications and change all fall within protection scope of the present invention defined by the claims.

In addition, the step that those skilled in the art will appreciate that above-described the whole bag of tricks can realize by the computer of programming.Here, some execution mode is intended to the overlay program storage device, and it is machine or computer-readable, and coding has machine can carry out or the computer executable instructions program, and the some or all of steps of said method are carried out in wherein said instruction.This program storage device can be for example Disk and tape, hard disk drive or optical readable digital data storage medium of magnetic recording medium for example.Execution mode also is intended to cover the computer that is programmed for the described step of carrying out said method.

Claims (16)

1. one kind is deployed with in the environment of at least one Microcell in a macrocell, and the method for the scope expansion bias of a described Microcell is adjusted in a base station of a Microcell, comprises step:

Adjust in the situation that determine to carry out scope expansion bias, the set of candidate's scope expansion bias is determined in the base station of a described Microcell, wherein in the set of candidate's scope expansion bias under each scope expansion bias except zero offset value, be associated with the signal interference ratio that each subscriber equipment of a described Microcell experiences according to the first criterion and be not less than first threshold;

And according to the second criterion, from the set of described candidate's scope expansion bias, select a scope expansion bias as the new scope expansion bias of a described Microcell.

2. method according to claim 1, wherein said first threshold is the target signal interference ratio of down control channel.

3. method according to claim 1, wherein said first threshold are the maximum in the minimum value of target signal interference ratio of the target signal interference ratio of down control channel and downstream data channel.

4. method according to claim 1, wherein said the first criterion is: each subscriber equipment will be associated with the power of the reference symbol that receives from its peripheral base station of its measurement and expand that base station bias and maximum with the scope of peripheral base station.

5. method according to claim 1 also comprises step:

The information of the power of the reference symbol that receives from its peripheral base station of measuring about the subscriber equipment of the base station of described other residential quarters to the base station requests of other residential quarters; And,

Receive the information of the power of the reference symbol that receives from its peripheral base station of measuring about the subscriber equipment of the base station of described other residential quarters from the base station of described other residential quarters.

6. method according to claim 5, wherein said the second criterion is: select to make according to the first criterion to have carried out subscriber equipment after the association of residential quarter from the set of described candidate's scope expansion bias, that scope expansion bias of the downlink throughput capacity maximum of system is as the new scope expansion bias of a described Microcell.

7. method according to claim 5, wherein under each the scope expansion bias in the set of candidate's scope expansion bias, carried out subscriber equipment after the association of residential quarter according to the first criterion, the downlink throughput capacity of system is not less than the downlink throughput capacity of the system under current scope expansion bias.

8. method according to claim 5, wherein said other residential quarters are described macrocell.

9. one kind is used for being deployed with in the environment of at least one Microcell at a macrocell, adjusts the device of the scope expansion bias of a Microcell, comprising:

Determining unit, be used in the situation that determine to carry out the adjustment of scope expansion bias, determine the set of candidate's scope expansion bias, wherein in the set of candidate's scope expansion bias under each scope expansion bias except zero offset value, be associated with the signal interference ratio that each subscriber equipment of a described Microcell experiences according to the first criterion and be not less than first threshold; And

Selected cell is used for according to the second criterion, selects a scope expansion bias as the new scope expansion bias of a described Microcell from the set of described candidate's scope expansion bias.

10. device according to claim 9, wherein said first threshold is the target signal interference ratio of down control channel.

11. device according to claim 9, wherein said first threshold are the maximum in the minimum value of target signal interference ratio of the target signal interference ratio of down control channel and downstream data channel.

12. device according to claim 9, wherein said the first criterion is: each subscriber equipment will be associated with the power of the reference symbol that receives from its peripheral base station of its measurement and expand that base station bias and maximum with the scope of peripheral base station.

13. device according to claim 9 also comprises:

Request unit is used for the information of the power of the reference symbol that receives from its peripheral base station from the subscriber equipment of the base station of described other residential quarters to the base station requests of other residential quarters that measure about; And,

Receiving element is used for receiving from the base station of described other residential quarters the information of the power of the reference symbol that receives from its peripheral base station of measuring about the subscriber equipment of the base station of described other residential quarters.

14. device according to claim 13, wherein said the second criterion is: select to make according to the first criterion to have carried out subscriber equipment after the association of residential quarter from the set of described candidate's scope expansion bias, that scope expansion bias of the downlink throughput capacity maximum of system is as the new scope expansion bias of a described Microcell.

15. device according to claim 13, wherein under each the scope expansion bias in the set of candidate's scope expansion bias, carried out subscriber equipment after the association of residential quarter according to the first criterion, the downlink throughput capacity of system is not less than the downlink throughput capacity of the system under current scope expansion bias.

16. device according to claim 13, wherein said other residential quarters are described macrocell.

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