CN101075830B - Method for determining down initial transmitting power - Google Patents

Abstract

The method comprises: considering the path losses and the time slot interference when calculating the downlink initial transmitted power in order to figure out the size of downlink initial transmitted power reasonably and to avoid the influence caused by oversized transmitted power or undersized transmitted power. During the process of just establishing the physical layer or re-allocating the channel or inter-cell switchover, even if there isn't the destination time slot interference measured value reported by UE, the invention can also figure out the downlink time slot interference, and use the downlink power control to calculate the downlink initial transmitted power so as either to ensure the success ratio of access and the Quos requirement or to avoid the heavy interference to other UEs.

Description

Determine the method for down initial transmitting power

Technical field

The present invention relates to communication system, be meant a kind of method of definite down initial transmitting power especially.

Background technology

Code division multiple access (CDMA) is a kind of modulation and multiple access technique based on spread spectrum communication, in cdma communication system, because base station and travelling carriage use the same wireless frequency range, the base station transmits to a certain travelling carriage all can cause interference to this sub-district and adjacent sub-district travelling carriage.Because CDMA mobile communication system is interference-limited self-interference system and has the near-far interference characteristic, for capacity and the coverage that maximizes system, guarantees the service communication quality, base station (Node B) need carry out rational descending power and distribute.

In Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) system, according to the division of control function of power in the system, power control is divided into open Loop Power control, inner loop power control and exterior ring power control.Just set up or channel when reconfiguring at physical channel, as initial access, switch to new sub-district etc., transmitting terminal can not obtain the feedback of the receiving terminal quality of reception and disturbed condition in advance, so adopt open Loop Power control to calculate the size of Initial Trans.

In up open Loop Power control, it is Interference Signal Code Power (ISCP that Node B can measure the ascending time slot interference, Interference Signal Code Power), user terminal (UE) is measured downlink path loss L, ISCP and L according to measuring can calculate up Initial Trans by up open Loop Power control.But in descending, just set up or handover procedure channel when reconfiguring at physical channel, UE can't measure descending time slot in advance and disturb.

Descending time slot disturbs main and UE has relation apart from the distance of base station node B and the size of system loading, if the distance of UE and base station is bigger, be that UE is in cell edge and the duty ratio of neighbor cell is bigger on every side, then the interference ratio of the suffered neighbor cell of UE is bigger; If the distance of UE and base station is smaller, promptly UE is in center of housing estate and the load of neighbor cell is low weight on every side, and then the suffered interference meeting of UE is smaller.

Existing implementation method is that down initial transmitting power adopts the method according to descending time slot maximum transmission power mean allocation.If base station down time slot maximum transmission power is P _DL-MAX, descending time slot has a N basic resources unit (BRU), if the business that UE inserts takies m BRU, then original allocation is for the descending power of this UE:

The method of existing this allocation of downlink initial power does not consider that downlink path loss and descending time slot disturb, so the down initial transmitting power that distributes is very inaccurate.If UE is closer apart from the base station, this moment, path loss was smaller, neighbor cell also can be smaller to the interference of this UE simultaneously, if the descending power size according to present mean allocation can be far longer than suitable down initial transmitting power, cause bigger bursty interference to impact to other UE, thereby cause the quality of other UE to worsen suddenly even call drop, and can reduce the coverage and the capacity of sub-district.If UE is distant apart from the base station, this moment, path loss can be bigger, neighbor cell is also bigger to the interference of this UE simultaneously, understands less than suitable down initial transmitting power according to the descending power size of present mean allocation, thereby causes initial access failure of this UE or UE handoff failure.

Summary of the invention

In view of this, the object of the present invention is to provide a kind of method of definite down initial transmitting power, make it consider that downlink path loss and descending time slot disturb.

For achieving the above object, technical scheme of the present invention is as follows:

A kind of method of definite down initial transmitting power may further comprise the steps:

A, calculation base station signal arrive the downlink path loss of user terminal UE position;

B, the tabulation of default descending time slot interference matrix, comprise in this tabulation UE and base station apart from S, the descending time slot load level D of neighbor cell on every side, determine the descending time slot interference value of described UE according to these two corresponding relations, wherein with the descending time slot interference;

According to the current distance S of this UE of downlink path loss evaluation and base station, by the default downlink path loss threshold value { L that comprises one or more downlink path loss values ₁, L ₂..., L _N-1; Described downlink path loss threshold value is divided at least one class in a certain order, each class corresponding one apart from S, and corresponding downlink path loss threshold interval of each class; Calculate the current downlink path loss value L of UE, determine the downlink path loss value L place threshold interval that this UE is current according to described downlink path loss threshold value, again according to described threshold interval obtain this UE and base station apart from S;

According to the descending time slot load level D of the current neighbor cell of the descending time slot of neighbor cell load Ld estimation UE, by the default descending time slot load threshold value { Ld that comprises one or more descending time slot load values ₁, Ld ₂... Ld _M-1; Described descending time slot load threshold value is divided at least one class in a certain order, the corresponding descending time slot load level D of each class, and the corresponding downlink path loss threshold interval of each class; Calculate the current descending time slot load Ld of UE, determine the descending time slot load Ld place threshold interval that UE is current, obtain current descending time slot load level D according to described threshold interval again according to described descending time slot load threshold value;

At corresponding relation, obtain the descending time slot interference value of described UE by the described descending time slot interference matrix tabulation of inquiry;

C, calculate down initial transmitting power by described descending time slot interference value.

Preferably, the method for the described calculating downlink path of step a loss is:

Use the reference transmit power PTX of basic Common Control Channel PCCPCH _PCCPCHDeduct the received power PCCPCH RSCP of the PCCPCH that UE receives, the difference that obtains is the downlink path loss.

Preferably, the described method of calculating the current descending time slot load Ld of UE is:

$\mathrm{Ld}=\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\α}}_i\·{\mathrm{Ld}}_i$

Wherein, Ld _iBe the descending time slot load of i neighbor cell, α _iIt is the weight coefficient that this neighbor cell descending time slot load disturbs the UE descending time slot; N is the number of neighbor cell.

Preferably, the described method of calculating the current descending time slot load Ld of UE is:

$\mathrm{Ld}=\mathrm{\α}\·\underset{i=1}{\overset{N_1}{\mathrm{\Σ}}}{\mathrm{Ld}}_i+\mathrm{\β}\underset{j=1}{\overset{N_2}{\mathrm{\Σ}}}{\mathrm{Ld}}_j$

Wherein, Ld _iBe the descending time slot load of first lap neighbor cell, Ld _jIt is the descending time slot load of the second circle neighbor cell; α is the weight coefficient that the first lap neighbor cell disturbs the UE descending time slot, and β is the weight coefficient that the second circle neighbor cell disturbs the UE descending time slot, N ₁Be the number of first lap neighbor cell, N ₂It is the number of the second circle neighbor cell.

Preferably, the method for the descending time slot load Ld of current each neighbor cell of described calculating UE is:

$\mathrm{Ld}=\mathrm{\γ}\·\underset{i=1}{\overset{M_1}{\mathrm{\Σ}}}{\mathrm{Ld}}_i+\mathrm{\λ}\underset{j=1}{\overset{M_2}{\mathrm{\Σ}}}{\mathrm{Ld}}_j$

Wherein, M ₁Be the very strong neighbor cell number of signal power to this UE, M ₂Be relative adjacent the more weak sub-district number of the signal power that arrives this UE, Ld _iBe according to the pilot tone very strong neighbor cell descending time slot load of the signal power to this UE that measurement is judged with arrival angle AOA, Ld _jBe according to pilot tone with AOA measurement judge the relative more weak neighbor cell descending time slot load of the signal power of this UE, γ and λ are respectively aforementioned M ₁And M ₂The weight coefficient of individual sub-district.

Preferably, the descending time slot of described i sub-district load Ld _iComputational methods be:

${\mathrm{Ld}}_i=\frac{{\mathrm{PTX}}_{\mathrm{use}}}{{\mathrm{PTX}}_{\mathrm{total}}}$

Wherein, PTX _UseIt is the transmitting power that descending time slot has used; PTX _TotalIt is total transmitting power that descending time slot allows use.

Preferably, the descending time slot of described i sub-district load Ld _iComputational methods be:

${\mathrm{Ld}}_i=\frac{{\mathrm{RU}}_{\mathrm{use}}}{{\mathrm{RU}}_{\mathrm{total}}}$

Wherein, RU _UseBe the resource units RU number that descending time slot has used, RU _TotalIt is the total RU number of descending time slot.

Preferably, the method for the described calculating down initial transmitting power of step c is:

P _DL-TX＝(SIR) _target+L+I

Wherein, (SIR) _TargetFor satisfying the target signal to noise ratio according to loaded service mapping on the channel of quality QoS demand; L is the downlink path loss, and I is the descending time slot interference value.

Preferably, described all operations carries out in radio network controller (RNC), after RNC calculates down initial transmitting power, further comprise: this down initial transmitting power is set up message by wireless link channel, or RB sets up message, or the physical channel reconfiguration message, or the transmission channel reconfiguration message, or the RB reconfiguration message is notified to the interior base station of Target cell that UE switches to.

The present invention has considered the factor of path loss and time slot interference when calculating down initial transmitting power, reasonably calculated the size of down initial transmitting power, thereby avoided the excessive or too small influence that causes of Initial Trans.Physical channel just set up channel heavily distributes or handover procedure in, the target downlink time slot interference measured value that reports even without UE, also can use the inventive method to calculate descending time slot disturbs, use open loop power control to calculate down initial transmitting power again, guaranteed access success rate and the QoS of survice quality requirement of UE, avoided again other UE are caused big interference simultaneously.Can improve the area coverage and the capacity of network like this, improve the performance of system.

Description of drawings

Fig. 1 is UE and S ₀And S _iThe relative distance schematic diagram in zone;

Fig. 2 is a schematic flow sheet of using the inventive method.

Embodiment

Below in conjunction with drawings and the specific embodiments the present invention is done detailed description further.

Thinking of the present invention is: the utilization open-loop power control method calculates down link Initial Trans size, emphasis reconfigures in the process at the initial foundation of channel or handover procedure and channel, arrive the path loss and the interference of the load estimate target downlink time slot of neighbor cell on every side of UE position according to base station signal, thereby solve the problem that can't obtain UE descending time slot interfere information in advance.

The formula that calculates the down initial transmitting power size according to open-loop power control method is as follows:

P _DL-TX＝(SIR) _target+L+I (1)

Wherein: (SIR) _TargetFor satisfying the target signal to noise ratio of QoS (QoS) demand; L is the downlink path loss, and I is that descending time slot disturbs size, i.e. descending time slot interference value.

Belonging to known technology according to bearer service mapping target signal to noise ratio, mainly is the corresponding relation that obtains bLock error rate under the miscellaneous service configuring condition (BLER) and signal to noise ratio (SIR) by link simulation and test, and this paper repeats no more.

The computational methods of downlink path loss L also are known technologies, and the computing formula of L size commonly used is as follows:

L＝PTX _PCCPCH-PCCPCH?RSCP (2)

Wherein: PTX _PCCPCHBe the reference transmit power of basic Common Control Channel (PCCPCH), PCCPCH RSCP is the received power size of the PCCPCH that receives of UE.

I is the interference size of UE place time slot, has just set up or channel when reshuffling at physical channel, and UE can't measure the size of access slot and neighbor cell switching target time slot ISCP in advance.Because descending time slot disturbs main and UE has relation apart from the distance of base station (Node B) and the size of system loading, if being more greatly UE, the distance of UE and base station is in cell edge, and the duty ratio of neighbor cell is bigger on every side, and then the interference ratio of the suffered neighbor cell of UE is bigger; If the smaller UE of being of the distance of UE and base station is in center of housing estate, and the load of neighbor cell is low weight on every side, and then the suffered interference meeting of UE is smaller.The following describes descending time slot interference and path loss and the relation of the load of neighbor cell on every side.

Usually, the model of propagation loss is the product of m sum of powers logarithm normal distribution normalized value of distance, and when UE was r apart from base station distance, propagation loss was proportional to:

L(r，ξ)＝r ^m10 ^ξ/10 (3)

Wherein: ξ is the decibel loss that shade causes, its average is 0, and standard variance is σ.

Suppose that cell pattern is a regular hexagon, makes k _uBe the average UE number in every sub-district, because the normalization sub-district is a regular hexagon, so its UE density is:

Referring to Fig. 1, establishing UE place Serving cell is S ₀, UE is to base station in service sector NodeB ₀Distance be r ₀(x, y), other neighbor cells are as S _iThe base station node B of sub-district _iDistance apart from UE is r _i(x, y), other neighbor cells to the interference size that this UE produces are:

$I=E\underset{S_0}{\∫\∫}\left[\frac{r_i^m(x,y){10}^{{\mathrm{\ξ}}_i/10}}{r_0^m(x,y){10}^{{\mathrm{\ξ}}_0/10}}\right]\mathrm{\κdA}(x,y)---\left(5\right)$

By formula (5) as can be known, to disturb size and UE to arrive the load of the distance of base station and neighbor cell relevant for descending time slot.Wherein, the load of κ characterization system, r ₀(x, y) and r _i(x, y) position of sign UE.Consider the feasibility of Project Realization, adopt the load according to path loss and peripheral cell that descending time slot is disturbed the method for estimating, detailed process is as follows:

RNC according to the L that calculates according to default downlink path loss threshold value { L ₁, L ₂..., L _N-1The path loss L of UE and base station in a certain order, as from closely to far, be divided into the n class, each class corresponding one apart from S, use respectively S1, S2 ..., Sn represents; N is a positive integer.Certainly, also can be according to from as far as near order branch.Below with near be example to order far away.

When L≤L1, S ∈ S1;

When L1＜L≤L2, S ∈ S2;

……

When L＞Ln-1, S ∈ Sn.

The descending time slot load Ld of neighbor cell is according to default descending time slot load threshold value { Ld around the RNC basis ₁, Ld ₂... Ld _M-1, descending time slot is loaded Ld in a certain order, heavy as arriving on the lenient side, be divided into the m class, the corresponding descending time slot load level D of each class, use respectively D1, D2 ..., Dm represents that m is a positive integer.Can certainly be according to from heavily to light order branch.Below being example to heavy order on the lenient side.

When Ld≤Ld1, Ld ∈ D1;

When Ld1＜Ld≤Ld2, Ld ∈ D2;

……

When Ld＞Ldm-1, Ld ∈ Dm.

Obtain m * n kind combined result altogether, each combination S _iD _jDisturb the reference value of I corresponding to a descending time slot.

In the TD-SCDMA system, descending time slot load Ld can carry out correspondence calculating according to the ratio that descending time slot transmitting power or descending time slot allocated channel number account for descending time slot total channel number.

All neighbor cell effects of load around descending time slot disturbs and is subjected to, and the descending time slot of each neighbor cell load is different to the descending time slot interference effect degree of UE.

The descending time slot interference of supposing UE mainly is subjected to the influence of N sub-district on every side, and then the load method of neighbor cell is as follows around the assessment:

$\mathrm{Ld}=\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\α}}_i\·{\mathrm{Ld}}_i---\left(6\right)$

Wherein: Ld _iThe descending time slot that is i sub-district meets, α _iBe the weight coefficient that this cell downlink time-slot load disturbs the UE descending time slot, α _iCharacterized the influence degree that disturb UE this sub-district.

Owing to adopted down beam shaping technology, RNC can obtain arrival angle (AOA) information of UE in the TD-SCDMA system, RNC can judge the relative position relation of certain neighbor cell and UE according to the AOA information of UE.So α in the formula (6) _iSize relevant with two aspect factors, the one, the distance between UE and certain neighbor cell base station, the 2nd, the relative position relation of UE and certain neighbor cell base station.

If the two adjacent rings sub-district disturbs size to play a leading role to the descending time slot of UE around supposing.And establish the first lap neighbor cell N is arranged ₁Individual, and suppose that first lap neighbor cell load is the same to the descending time slot interference effect degree of UE; The second circle neighbor cell has N ₂Individual, and suppose that the second circle neighbor cell load also is the same to the descending time slot interference effect degree of UE, then the load method of neighbor cell is as follows around the assessment:

$\mathrm{Ld}=\mathrm{\α}\·\underset{i=1}{\overset{N_1}{\mathrm{\Σ}}}{\mathrm{Ld}}_i+\mathrm{\β}\underset{j=1}{\overset{N_2}{\mathrm{\Σ}}}{\mathrm{Ld}}_j---\left(7\right)$

Wherein: Ld _iBe the descending time slot load of first lap neighbor cell, Ld _jIt is the descending time slot load of the second circle neighbor cell; The α weight coefficient that to be the first lap neighbor cell disturb the UE descending time slot, the weight coefficient that the β second circle neighbor cell disturbs the UE descending time slot, α is more than or equal to β usually, i.e. α 〉=β.

If in the UE handoff procedure, RNC judges M by pilot measurement and AOA information ₁Individual sub-district is very strong to the signal power of this UE, and promptly the descending time slot that produces disturbs also very strong; M in addition ₂Individual sub-district is owing to reasons such as distance are weak relatively to the signal power of this UE, and then the load method of neighbor cell is as follows around the assessment:

$\mathrm{Ld}=\mathrm{\γ}\·\underset{i=1}{\overset{M_1}{\mathrm{\Σ}}}{\mathrm{Ld}}_j+\mathrm{\λ}\underset{j=1}{\overset{M_2}{\mathrm{\Σ}}}{\mathrm{Ld}}_j---\left(8\right)$

Wherein: Ld _iBe the very strong neighbor cell descending time slot load of signal power of judging this UE according to pilot tone and AOA measurement, Ld _jBe according to pilot tone with AOA measurement judge the relative more weak neighbor cell descending time slot load of the signal power of this UE; γ and λ are respectively aforementioned M ₁And M ₂The weight coefficient of individual sub-district, usually γ is more than or equal to λ, i.e. γ 〉=λ.

Because Ld _jAnd Ld _iRepresented implication is identical, below only with Ld _iFor example describes.

The descending time slot load Ld of each sub-district _iCalculating has two kinds of methods, and the one, can be according to the descending time slot transmitting power, the 2nd, can account for the ratio of descending time slot total channel number according to descending time slot allocated channel number.So Ld in formula (6), (7), (8) _iComputational methods as follows:

Method one: ${\mathrm{Ld}}_i=\frac{{\mathrm{PTX}}_{\mathrm{use}}}{{\mathrm{PTX}}_{\mathrm{total}}}---\left(9\right)$

Wherein: PTX _UseIt is the transmitting power that descending time slot has used; PTX _TotalIt is total transmitting power that time slot allows use.

Method two: ${\mathrm{Ld}}_i=\frac{{\mathrm{RU}}_{\mathrm{use}}}{{\mathrm{RU}}_{\mathrm{total}}}---\left(10\right)$

Wherein: RU _UseBe resource units (RU) number that descending time slot has used, RU _TotalIt is the total RU number of descending time slot.

That is to say the descending time slot interference matrix of default M * N tabulation (ISCP) in RNC _{M * N}, comprise in this tabulation UE and base station apart from S, the corresponding relation of these two of descending time slot load level D and the descending time slot interference value I of neighbor cell on every side.

When UE initiated initial call or switch UE to switch to a new sub-district, loss obtained the current distance S of this UE and base station according to downlink path, estimated the descending time slot load level D of the neighbor cell that UE is current according to the descending time slot of the neighbor cell Ld that loads; By inquiring about the corresponding relation of described descending time slot interference matrix tabulation, the descending time slot that obtains described UE disturbs.For example, by searching the capable S in the Matrix List _iWith row D _j, in the matrix tabulation, find corresponding interference value I, afterwards, again I is brought into formula (1), can obtain the Initial Trans of down link.

The descending time slot of above-mentioned neighbor cell load Ld calculates by formula (6) or formula (7) or formula (8).

Below in conjunction with embodiment the present invention is done explanation again.

Suppose that a certain speech UE needs to switch, calculate its down link Initial Trans in the switching target small area target time slot, referring to Fig. 2, detailed process is as follows:

Step 201 is shone upon the target signal to noise ratio (SIR) that satisfies QoS of survice according to loaded service on the channel _TargetThe calculation base station signal arrives the downlink path loss of UE terminal UE position, and its concrete computational methods such as formula (2) repeat no more herein.

Above-mentioned two steps calculate and do not have strict sequencing.

Step 202 is determined the descending time slot interference value of UE according to the load of described downlink path loss and peripheral cell.Be specially in this example:

Default 3 * 3 descending time slot interference matrix tabulation, comprise in this tabulation UE and base station apart from S, the corresponding relations of these two of descending time slot load level D and the descending time slot interference of neighbor cell on every side; Promptly set walking along the street footpath loss threshold value { L ₁, L ₂, with described downlink path loss threshold value in a certain order,, be divided three classes as far away near, each class corresponding one apart from S, as representing with S1, S2, S3 respectively, and downlink path loss threshold interval of each class correspondence; Set capable time-slot load threshold value { Ld ₁, Ld ₂, heavy as arriving on the lenient side with described descending time slot load threshold value in a certain order, be divided three classes, the corresponding descending time slot load level D of each class, as representing with D1, D2, D3 respectively, and downlink path loss threshold interval of each class correspondence.Promptly

As L≤L ₁The time, S ∈ S1;

Work as L ₁＜L≤L ₂The time, S ∈ S2;

As L＞L ₂The time, S ∈ S3;

As Ld≤Ld ₁The time, Ld ∈ D1;

Work as Ld ₁＜Ld≤Ld ₂The time, Ld ∈ D2;

As Ld＞Ld ₂The time, Ld ∈ D3;

And S1, S2, S3 and D1, D2, D3 make up respectively, 9 kinds of combined result arranged, each combination S _iD _jCorresponding to a descending time slot interference value I reference value.

Calculate the current downlink path loss value L of UE, determine the downlink path loss value L place threshold interval that this UE is current according to described downlink path loss threshold value, again according to described threshold interval obtain this UE and base station apart from S.

Calculate the current descending time slot load Ld of UE, determine the descending time slot load Ld place threshold interval that UE is current, obtain descending time slot load level D according to described threshold interval again according to described descending time slot load threshold value.Wherein, the current descending time slot load Ld of UE can calculate by formula (6), (7) or (8).

According to obtain apart from S and descending time slot load level D, inquire about the tabulation of described descending time slot interference matrix, can obtain descending time slot interference value I.

It is that formula (1) calculates down initial transmitting power that step 203, the descending time slot interference value by described target signal to noise ratio, downlink path loss and UE are utilized open-loop power control method.

Described all calculating down initial transmitting power operations are all carried out in RNC, after RNC calculates down initial transmitting power, this down initial transmitting power is set up message by wireless link channel, or RB sets up message, or physical channel reconfiguration message, or the transmission channel reconfiguration message, or the RB reconfiguration message is notified to the interior base station of Target cell that UE switches to.

The present invention has considered the factor of path loss and time slot interference when calculating down initial transmitting power, can compare the size of accurately reasonably calculating down initial transmitting power, thereby avoid the excessive or too small influence that causes of Initial Trans.Physical channel just set up channel heavily distributes or handover procedure in, the target time slot interference measure that reports even without UE, also can use the inventive method to estimate descending time slot disturbs, thereby assistance open loop power control, can guarantee access success rate and the QoS of survice quality requirement of UE, can avoid again other UE are caused big interference simultaneously.Can improve the area coverage and the capacity of network like this, improve the performance of system.

The above is preferred embodiment of the present invention only, is not to be used to limit protection scope of the present invention.All any modifications of being done within the spirit and principles in the present invention, be equal to replacement, improvement etc., all be included in protection scope of the present invention.

Claims (9)

1. the method for a definite down initial transmitting power is characterized in that, may further comprise the steps:

A, calculation base station signal arrive the downlink path loss of user terminal UE position;

B, the tabulation of default descending time slot interference matrix, comprise in this tabulation UE and base station apart from S, the descending time slot load level D of neighbor cell on every side, determine the descending time slot interference value of described UE according to these two corresponding relations, wherein with the descending time slot interference;

According to the current distance S of this UE of downlink path loss evaluation and base station, by the default downlink path loss threshold value { L that comprises one or more downlink path loss values ₁, L ₂..., L _N-1; Described downlink path loss threshold value is divided at least one class in a certain order, each class corresponding one apart from S, and corresponding downlink path loss threshold interval of each class; Calculate the current downlink path loss value L of UE, determine the downlink path loss value L place threshold interval that this UE is current according to described downlink path loss threshold value, again according to described threshold interval obtain this UE and base station apart from S;

According to the descending time slot load level D of the current neighbor cell of the descending time slot of neighbor cell load Ld estimation UE, by the default descending time slot load threshold value { Ld that comprises one or more descending time slot load values ₁, Ld ₂... Ld _M-1; Described descending time slot load threshold value is divided at least one class in a certain order, the corresponding descending time slot load level D of each class, and the corresponding downlink path loss threshold interval of each class; Calculate the current descending time slot load Ld of UE, determine the descending time slot load Ld place threshold interval that UE is current, obtain current descending time slot load level D according to described threshold interval again according to described descending time slot load threshold value;

By the corresponding relation of the described descending time slot interference matrix tabulation of inquiry, obtain the descending time slot interference value of described UE again;

C, calculate down initial transmitting power by described descending time slot interference value.

2. method according to claim 1 is characterized in that, the method for the described calculating downlink path of step a loss is:

Use the reference transmit power PTX of basic Common Control Channel PCCPCH _PCCPCHDeduct the received power PCCPCH RSCP of the basic Common Control Channel PCCPCH that UE receives, the difference that obtains is the downlink path loss.

3. method according to claim 1 is characterized in that, the method for the descending time slot load Ld that described calculating UE is current is:

Wherein, Ld _iBe the descending time slot load of i neighbor cell, α _iIt is the weight coefficient that this neighbor cell descending time slot load disturbs the UE descending time slot; N is the number of neighbor cell.

4. method according to claim 1 is characterized in that, the method for the descending time slot load Ld that described calculating UE is current is:

Wherein, Ld _iBe the descending time slot load of first lap neighbor cell, Ld _jIt is the descending time slot load of the second circle neighbor cell; α is the weight coefficient that the first lap neighbor cell disturbs the UE descending time slot, and β is the weight coefficient that the second circle neighbor cell disturbs the UE descending time slot, N ₁Be the number of first lap neighbor cell, N ₂It is the number of the second circle neighbor cell.

5. method according to claim 1 is characterized in that, the method for the descending time slot load Ld of current each neighbor cell of described calculating UE is:

Wherein, M ₁Be the very strong neighbor cell number of signal power to this UE, M ₂Be relative adjacent the more weak sub-district number of the signal power that arrives this UE, Ld _iBe according to the pilot tone very strong neighbor cell descending time slot load of the signal power to this UE that measurement is judged with arrival angle AOA, Ld _jBe according to pilot tone with arrive angle AOA measurements and judge the relative more weak neighbor cell descending time slot of signal power of this UE and load, γ and λ are respectively aforementioned M ₁And M ₂The weight coefficient of individual sub-district.

6. according to claim 3,4 or 5 described methods, it is characterized in that the descending time slot load Ld of described i sub-district _iComputational methods be:

Wherein, PTX _UseIt is the transmitting power that descending time slot has used; PTX _TotalIt is total transmitting power that descending time slot allows use.

7. according to claim 3,4 or 5 described methods, it is characterized in that the descending time slot load Ld of described i sub-district _iComputational methods be:

Wherein, RU _UseBe the resource units RU number that descending time slot has used, RU _TotalIt is the total RU number of descending time slot.

8. method according to claim 1 is characterized in that, the method for the described calculating down initial transmitting power of step c is:

P _DL-TX＝(SIR) _target+L+I

Wherein, (SIR) _{Tart et}For satisfying the target signal to noise ratio according to loaded service mapping on the channel of quality QoS demand; L is the downlink path loss, and I is the descending time slot interference value.

9. method according to claim 1, it is characterized in that, all operations carries out in radio network controller (RNC), after RNC calculates down initial transmitting power, further comprise: this down initial transmitting power is set up message by wireless link channel, or radio bearer RB sets up message, or the physical channel reconfiguration message, or the transmission channel reconfiguration message, or radio bearer RB reconfiguration message is notified to the interior base station of Target cell that UE switches to.

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