CN1625089A - Method of realizing dynamic quickly regulating for HSDPA system - Google Patents

Abstract

A method for dynamic fast dispatch and used for HSDPA system, including: assure the number of the movable users; assure who are the movable users; distribute the code word resource for the movable users. The above number of the movable users is determined by the reference value of the number of all movable users determined by the dispatch strategy and the average channel quality of all connected users, and determines which users are the movable users according to the transmitting priority of every connected user. Then, dispatch primarily for every movable user according to the flooding principle with the limitation condition of non-surpassing the recommending value of the movable users, to assure the lowest transmitting information speed of all movable users reach the maximum value. The method of this invention, according to the resource sharing manner of the instantaneous channel condition and code score re-use, fully makes use of the limited code word resource, and gives due consideration of system throughput and equality and dynamically distributes the time-domain and code-domain resources of HSDPA users.

Description

A kind of method that is used for the realization dynamic fast dispatch of HSDPA system

Technical field

The present invention relates to 3-G (Generation Three mobile communication system), more specifically to a kind of method of realization dynamic fast dispatch of the HSDPA technology that is used for the WCDMA system.

Background technology

Wideband CDMA (WCDMA) is one of main flow system of the third generation (3G) mobile communication system.The HSDPA that proposes in its R5 version (High Speed Data PacketAccess) (high-speed data packets access) technology has become hot research in recent years.A kind of evolution as WCDMA, the introducing of this high-speed packet transmission technology has improved the throughput of system, reduced round trip delay and made the data packet transmission ability of WCDMA obtain further reinforcement, made its descending peak data rate that can support bring up to 10Mbps by original 2Mbps.

The HSDPA technology has been introduced new transmission channel a: HS-DSCH (high speed descending sharing channel), littler Transmission Time Interval (TTI): 2ms, and adopted adaptive modulation and coding (AMC), mixed automatic retransmission request (Hybrid ARQ), fast dispatch (Fast Scheduling), fast cell is selected, new technologies such as multi-input/output antenna processing.Wherein, fast dispatch is a key issue of design, and the quality of fast dispatch strategy has determined the performance of HSDPA system to a great extent.

The fast dispatch strategy is intended to provide the transfer of data of two-forty to the user who is fit to, utilizes user diversity to improve throughput of system, takes into account fairness problem simultaneously.It distributes time-domain resource (time slot, i.e. the user's time quantum that can accept to serve) and a sign indicating number territory resource (the physical channel HS-PDSCH that distinguishes according to different spread spectrum code words) making full use of under the condition of instantaneous channel conditions to each user.In the HSDPA system, (hereinafter the number with these code words is called code source) can be managed by RNC for the code word number that scheduling strategy distributes in each sub-district, and the concrete assignment problem of code source between the user solved by the MAC-hs entity that is arranged in Node B.

In existing fast dispatch strategy, the overwhelming majority has only considered in certain TTI only to be the strategy of user's service.Also there is the minority strategy to utilize the resource-sharing mode of code division multiplexing in addition.

For only consider to be the strategy of user's service in certain TTI, when channel condition is good, this class strategy can use code source effectively, but in the time of bad channel conditions, the code source of a part will be wasted, because unique user only can use the sub-fraction of code source in this case.This is worthless in engineering practice.

For the strategy that utilizes code division multiplexing, this will be a trend of research and engineering practice.Only in this way could use Limited resources effectively, give full play of the advantage of CDMA technology, promptly improve the availability of frequency spectrum by code division multiplexing.Yet it's a pity that fairness problem is not considered in the too simplification that existing this class strategy has, and be precondition less than available code source that this hypothesis and actual conditions are not inconsistent with number of users.Because, although the spendable number of codewords of Node B is certain, but RNC is when carrying out access control (CAC), might allow fully to keep connecting at high level simultaneously greater than the user of available codeword number, and use time division multiplexing to allow all users can enjoy the service of system in physical layer, for the business of no delay requirement, the probability that this situation occurs is especially big.Some strategies in addition attempt to give in a TTI all users that service is provided, and more for a long time, this policy calculation amount is too big in number of users, does not meet fast dispatch and requires the simple precondition of algorithm.

Summary of the invention

Purpose of the present invention just provides the method for the realization dynamic fast dispatch of a kind of HSDPA of being used for system, and it can overcome the above-mentioned technical problem that exists in the prior art.

For this reason, the method according to the realization dynamic fast dispatch that the invention provides a kind of HSDPA of being used for system may further comprise the steps: the number of determining active user; Determine which user is active user; For active user distributes spendable code source.

According to the present invention, the number of above-mentioned active user is determined according to the fiducial value by the active user number of scheduling strategy decision is connected the user with all average channel quality, and is determined that according to transmission priority of each connection user which user is an active user.Then, tentatively distribute for each active user earlier, and be restrictive condition, reach maximum to guarantee the minimum information speed that all active users can transmit with the recommendation that is no more than active user by water-filling.Afterwards, if code source still has residue, giving the best active user of channel quality with the remainder codewords resource allocation, improving the throughput of whole system, and is restrictive condition with the ability that is no more than active user.

Method in the realization dynamic fast dispatch that is used for the HSDPA system according to the present invention, scheduling strategy is according to the resource-sharing mode of instantaneous channel conditions and code division multiplexing, made full use of limited code source, when taking into account throughput of system and fairness, dynamically distributed time domain and sign indicating number territory resource for each user of HSDPA.It has at first dynamically determined in given TTI which user to be chosen as the problem of active user, promptly how to give to have connected the problem that the user distributes time-domain resource, and this also is that we claim this strategy to be the reason of dynamic strategy; Secondly, it has solved and how to have given active user assigned code territory problem of resource.

Among the present invention, the inventor considers this characteristic that becomes when the number of users of connecting system is, so at first determine that according to the channel quality information of each reporting of user the next TTI of number of active user allows the user's of participation code division multiplexing number Us when design fast dispatch strategy.This is a new thought, and other strategies were not considered.Will foundation channel quality information be the channel quality Warning Mark (CQI) that already provided UE feeds back to Node B in the 3GPP standard.

Consider the asymmetry of Network, the present invention has also introduced a parameter ρ that can dispose voluntarily for operator, considers the loading condition difference of each sub-district, even when only considering the situation of single sub-district, it is also inequality at the loading condition of different time sections.Utilize this parameter, the configuration of each sub-district can be relatively independent, and operator can adjust flexibly according to actual conditions (busy not busy sub-district or busy period).

In addition, the present invention is provided with priority for each user.Owing to taken into account user's channel quality and on average successful information transmitted speed, the setting of priority has not only been followed the tracks of each user's instantaneous channel variation but also has been introduced certain fairness.The Us of a priority maximum user is selected active user.

At last, the present invention gives this Us user's distribution codeword resource according to water-filling.From user perspective, the minimum information speed that all users can successfully be transmitted has reached maximum, has promptly demonstrated fully fairness.From the angle of network, the processing of code division multiplexing has improved the throughput of system.

This invention utilizes the rule that provides in the 3GPP agreement, uses the main foundation of existing channel quality Warning Mark CQI as scheduling strategy, the compliant requirement, and exploitativeness is good.

Introduce embodiments of the invention in detail below in conjunction with accompanying drawing.

Description of drawings

Fig. 1 shows the schematic diagram of a kind of WCDMA system;

Fig. 2 shows the input and output information according to the method for the realization dynamic fast dispatch of the HSDPA of being used for of the present invention system;

Fig. 3 shows the flow chart according to the method for the realization dynamic fast dispatch of the HSDPA of being used for of the present invention system;

Shown in Fig. 4 is a part of using scheduler in the MAC-hs entity of method of realization dynamic fast dispatch of the present invention, and the relation of implementing module of the present invention and correlation module has been described.

Embodiment

Fig. 1 shows the schematic diagram of a kind of WCDMA system.As shown in Figure 1, the WCDMA system is made up of core net (CN), wireless access network and user's set (UE).UTRAN comprises a plurality of RNS that are connected to CN by the Iu interface.Different RNS links to each other by the Iur interface.A RNS comprises a RNC and one or more Node B.Node B is connected on the RNC by Iub interface.A Node B manages one or more sub-districts.

In the method that is used for the realization dynamic fast dispatch of HSDPA system according to the present invention, the user is divided into two classes: connect user and active user.Connect the user and be all connecting system and users of keeping signaling to connect at high level, and active user is an output result of scheduling strategy, i.e. the next TTI of scheduling strategy decision wants those users serviced, that participate in code division multiplexing.

The enforcement of scheduling strategy needs Node B and RNC and the necessary information of UE exchange.Fig. 2 has provided the particular content of these information, has also provided the input and output information of this scheduling strategy simultaneously.

As shown in Figure 2, all sub-districts that possesses the HSDPA function, in the cell configuration stage, RNC will be configured Node B, by its code source that distributes for HSDPA of NBAP signaled; Each connect user connect establishment stage also can be by the i.e. code source that uses of the multipotency of this user of its ability of NBAP signaled Node B, this parameter is stored in the internal memory of Node B for future use afterwards.On ascending control channel HS-DPCCH (High-Speed Dedicated Physical Control Channel), each connects the user and periodically gives Node B with the CQI value reporting.Determine after the active user, ability and its CQI value that reports according to active user, this scheduling strategy table look-up (this CQI table is the information that is stored in the internal memory of Node B), with one group of parameter learning that each active user is recommended, for example: the code source that transmission block size and needing is used etc.According to these parameters, this scheduling strategy carries out corresponding calculated, exports result of calculation then: the User Recognition sign (UE-ID) of active user and distributed to the code source of this active user.

Fig. 3 shows the flow chart according to the method for the realization dynamic fast dispatch of the HSDPA of being used for of the present invention system.

As shown in Figure 3, according to all connect the CQI value of reporting of user in the sub-district, implement according to the following steps according to the method for the realization dynamic fast dispatch of the HSDPA of being used for of the present invention system:

Step S1: the number Us that determines active user.

User's number is subjected in the sub-district all constraints that connect user's average channel quality and dynamic change on the basis of fiducial value.

Step S2: determine that specifically which user is an active user.

Calculate the transmission priority that each connects the user, i.e. CQI value and the average ratio that successfully transmits information rate; Us the user that priority is the highest is active user.

Step S3: for active user distributes spendable code source.

Tentatively distribute for each active user earlier, reach maximum, and be restrictive condition with the recommendation that is no more than active user to guarantee the minimum information speed that all active users can transmit by water-filling.If code source still has residue, step afterwards is a restrictive condition with the ability that is no more than active user.The remainder codewords resource allocation is to the maximum active user of CQI value, to improve the throughput of whole sub-district; If it all is maximum that the CQI value of a plurality of active users is arranged, still presses water-filling and in these a plurality of users, distribute the remainder codewords resource.

Above-mentioned steps is once calculated at each TTI, carries out at next TTI.

Suppose that total user U is individual in the set A that connects the user in the current area, have user Us in the set B of the active user of scheduling strategy decision, its fiducial value is Us _BaseThe CQI value that user i reports is CQI_value _i

Ability code_max according to UE _iAnd CQI_value _iCan obtain following parameter (recommendation of UE) by tabling look-up:

The big or small CQI_TBS of transmission block _iThe code source CQI_code that UE need use _i

If the spendable altogether code source of scheduling strategy is Nc, it is by system configuration; User i is C at t TTI success information transmitted bit _{I, t,}The TTI number that user i has connected is T _i, during this period of time average successful information transmitted speed is R _iThe transmission priority of user i is pr _iThe code source that scheduling strategy distributes for user i is code _iBut the information transmitted bit is r _i

1) introduces the concrete implementation step of step S1 shown in Figure 3 below in detail.

At first, determine in the current area fiducial value Us of the user's number Us in the set B of the active user that next TTI carries out _Base

Wherein, Us _UpBe user's number that this sub-district can be served in a TTI altogether, it is by system configuration, and its theoretical span is [1, Nc], and the little value (being no more than 5) of the suggestion amount of exhausting is because the total throughout of this big more whole sub-district of value is just more little.ρ is the adjustable parameter of reserving for operator, its value less than 1 greater than 0.Because the big or small dynamic change of U value of the different periods of different districts or same cells, operator can adjust flexibly.When the assembly average of U value during near Nc, the general desirable 0.2-0.3 of ρ value; If the value of U ρ value bigger than normal can suitably reduce.Symbol Expression rounds downwards.

Then, calculate in the current area average channel quality of U user in all set A that connect users.In the present embodiment, this average channel quality represented by the mean value that UE feeds back to the channel quality Warning Mark CQI of Node B, promptly

By

Expression.

Next, with half of the difference of the maximum of the CQI value of all users in above-mentioned mean value and the current area and minimum value $\frac{\mathrm{CQI}\_{\mathrm{value}}_{\max }-\mathrm{CQI}<figure-callout\; id="2"\; label="\_\; value\; min"\; filenames="A20031010904400141.png"\; state="\{\{state\}\}">\_</figure-callout>{\mathrm{value}}_{\min }{}_{}}{2}$ Compare.

If $\frac{\underset{i\&Element;A}{\mathrm{\&Sigma;}}\mathrm{CQI}\_{\mathrm{value}}_i}{U}>\frac{\mathrm{CQI}\_{\mathrm{value}}_{\max }-\mathrm{CQI}<figure-callout\; id="2"\; label="\_\; value\; min"\; filenames="A20031010904400141.png"\; state="\{\{state\}\}">\_</figure-callout>{\mathrm{value}}_{\min }{}_{}}{2},$

Then the number of active user increases by 1 on the basis of its fiducial value, i.e. Us=Us _Base+ 1, generally preferably under the situation, can be more user's service at each user's channel quality like this.Otherwise, if satisfy condition Us _Base＞1, the number of active user reduces 1 on the basis of its fiducial value, i.e. Us=Us _Base-1, can under the general relatively poor situation of each user's channel condition, reduce scheduling overhead like this; Otherwise end step S1.

Wherein, CQI_value _MaxBe that all connect CQI value maximum among the user, CQI_value _MinBe that all connect CQI value minimum among the user.

2) introduce the concrete implementation step of step S2 shown in Figure 3 below in detail.

All U user among the pair set A calculates on average successful information transmitted speed R according to following formula _iTransmission priority pr with user i _i:

${\stackrel{\&OverBar;}{R}}_i=\frac{1+\underset{t=1}{\overset{T_i-1}{\mathrm{\&Sigma;}}}{C}_{i,t}}{(T_i-1)*{\mathrm{<figure-callout\; id="1"\; label="T"\; filenames="A20031010904400141.png"\; state="\{\{state\}\}">T</figure-callout>}}_1};$

$p{r}_i=\frac{\mathrm{CQI}\_{\mathrm{value}}_i}{{\stackrel{\&OverBar;}{R}}_i};$

Wherein, T ₁The length of express time interval T TI, in the present embodiment, T ₁=2ms.

User's channel quality had both been considered in the setting of priority, just allowed the better user of channel quality to have higher priority, to improve the throughput of system; That has also considered the user on average successfully transmits information rate, just on average successfully transmits the high more user of information rate, and priority is low more.Such consideration is in order to introduce certain fairness, to can not get service for a long time to prevent the relatively poor user of channel quality (for example those are positioned at the user of cell boarder).

Priority is arranged from big to small, pr _iUs maximum user is active user.

3) introduce the concrete implementation step of step S3 shown in Figure 3 below in detail.

From set B, select an active user i arbitrarily and be code word of its distribution, but distribute information transmitted bit r simultaneously _i=CQI_TBS _i/ CQI_code _i

The recommendation that each code assignment in the remainder codewords resource is no more than UE for the code source that has distributed, but and that minimum user of the transmission information bit of having distributed.The basic principle of Here it is water-filling.This process circulates Nc-1 time altogether, if all code sources have been assigned with, perhaps the code source that all users have distributed in the set B has all reached the recommendation of CQI report, and code promptly satisfies condition _j=CQI_code _j, for all j ∈ B, then end loop, tentatively code source distribution end.

Just, each circulation searching user n satisfies: r _n＜r _jFor all code _j＜CQI_code _j, j ∈ B;

r _n＝r _n+CQI_TBS _n/CQI_code _n；

code _n＝code _n+1。

If the code source that all active users have distributed has all reached the recommendation of CQI report, and when still having the remainder codewords resource, carry out following operation.

If $\underset{i\&Element;B}{\mathrm{\&Sigma;}}{\mathrm{code}}_i<\mathrm{Nc}$

The code source of then seeking CQI value maximum and being assigned to is less than the active user of its ability, promptly seeks user n and satisfies: CQI_value _n〉=CQI_value _jFor all code _j＜code_max _j, j ∈ B;

C＝C+{n}

If have only a user n among the set C

Then ${\mathrm{code}}_n={\mathrm{code}}_n+(\mathrm{Nc}-\underset{i\&Element;B}{\mathrm{\&Sigma;}}{\mathrm{code}}_i);$

If code _n＞code_max _n,

Code then _n=code_max _n, that is to say that the code word of distributing to this user can not surpass this user's ability.

Otherwise by water-filling remainder codewords is distributed among the C in set, be assigned with up to all code sources, perhaps the code source that has been assigned to of all active users has all reached till its ability.

The present invention is a part that is positioned at this functional entity of MAC-hs entity scheduler (Scheduler), and it is connected as shown in Figure 4 with interior other modules of scheduler.Input information according to the method for the realization dynamic fast dispatch of the HSDPA of being used for of the present invention system is explained in detail by Fig. 2, and one of its output result: the UE-ID of active user, be the interior processed control module (Priority handling control) of scheduler and the input information of HARQ control module (HARQ control), this information helps serviced formation and the HARQ entity of they decisions; Another exports the result: distributing to the code source and the corresponding UE-ID of each active user, is the input information that transformat and combination of resources are selected (TFRC selection) module, and this information helps suitable transformat and the codeword information of its decision.

In conjunction with the accompanying drawings the specific embodiment of the present invention is described above.It should be noted, the invention is not restricted to above-mentioned execution mode, under the premise of without departing from the spirit of the present invention, those skilled in the art can carry out multiple modifications and changes.

Claims (12)

1. method that is used for the realization dynamic fast dispatch of HSDPA system may further comprise the steps:

Determine the number of active user;

Determine which user is active user;

For active user distributes spendable code source.

2. the method that is used for the realization dynamic fast dispatch of HSDPA system as claimed in claim 1, the number of wherein said active user is determined according to the channel quality information of all connection reporting of user in the sub-district.

3. the method that is used for the realization dynamic fast dispatch of HSDPA system as claimed in claim 2, wherein said channel quality information are the channel quality Warning Mark (CQI) that UE feeds back to Node B.

4. the method that is used for the realization dynamic fast dispatch of HSDPA system as claimed in claim 3, the number of wherein said active user is definite according to the fiducial value by all active user numbers of scheduling strategy decision is connected the user with all average channel quality.

5. the method that is used for the realization dynamic fast dispatch of HSDPA system as claimed in claim 4, the fiducial value of wherein said active user number is determined by following formula:

In the formula, ρ is the adjustable factor of reserving for operator; Us _UpBe user's number that a sub-district can be served in a TTI altogether, its span is [1, Nc]; Nc is that RNC is the code source of HSDPA configuration; Symbol

Expression rounds downwards.

6. the method that is used for the realization dynamic fast dispatch of HSDPA system as claimed in claim 4, wherein said all connection users' average channel quality refers to

$\frac{\underset{i\&Element;A}{\mathrm{\&Sigma;}}\mathrm{CQI}\_\mathrm{valu}{e}_i}{U}$

Wherein, A is all set that connect the user in the current area, and U is the user's number in the set A, CQI_value _iRefer to the CQI value that reports of user i.

7. the method that is used for the realization dynamic fast dispatch of HSDPA system as claimed in claim 1, the step of the number of wherein said definite active user comprises the steps:

Calculate in the current area fiducial value of the user's number in the set B of the active user that next TTI carries out

Calculate the mean value of the CQI of all users in the set A that connects the user in the current area

$\frac{\underset{i\&Element;A}{\mathrm{\&Sigma;}}\mathrm{CQI}\_\mathrm{valu}{e}_i}{U}$

Judge $\frac{\underset{i\&Element;A}{\mathrm{\&Sigma;}}\mathrm{CQI}\_{\mathrm{value}}_i}{U}>\frac{\mathrm{CQI}\_{\mathrm{value}}_{\max }-\mathrm{CQI}\_{\mathrm{value}}_{\min }}{2}$ Whether set up;

If set up, then the user's number in the set B of active user

Us＝Us _base+1

If be false, then judge whether the Us that satisfies condition _Base＞1

If satisfy this condition, then Us=Us _Base-1, otherwise the calculating of ending activity user number,

Wherein, ρ is the adjustable factor of reserving for operator; Us _UpBe user's number that a sub-district can be served in a TTI altogether, its span is [1, Nc], and Nc is that RNC is the spendable altogether code source of scheduling strategy of HSDPA configuration, symbol Expression rounds downwards, and A is all set that connect the user in the current area, and U is the user's number in the set A, CQI_value _iRefer to the CQI value that reports of user i, CQI_value _MaxBe CQI value maximum among all users in the set A, CQI_value _MinIt is CQI value minimum among all users in the set A.

8. the method that is used for the realization dynamic fast dispatch of HSDPA system as claimed in claim 1 wherein determines that according to each transmission priority that connects the user which user is active user.

9. the method that is used for the realization dynamic fast dispatch of HSDPA system as claimed in claim 8, wherein said transmission priority refer to the size of the ratio of the CQI value of user i and its successful information transmitted speed.

10. the method that is used for the realization dynamic fast dispatch of HSDPA system as claimed in claim 8, the Us of its a medium priority maximum user is chosen to be the active user of next TTI.

11. the method that is used for the realization dynamic fast dispatch of HSDPA system as claimed in claim 9, the successful information transmitted speed of wherein said user i is

${\stackrel{\&OverBar;}{R}}_i=\frac{1+\underset{t=1}{\overset{T_i-1}{\mathrm{\&Sigma;}}}{C}_{i,t}}{(T_i-1)*T_I}$

Wherein, C _{I, t}For user i at t TTI success information transmitted bit, T _iBe the TTI number that user i has connected, T _lWidth for TTI.

12. the method that is used for the realization dynamic fast dispatch of HSDPA system as claimed in claim 1 wherein distributes the step of spendable code source to comprise the steps: for each user in the set of active user

(a) selecting a user arbitrarily also is that it distributes a code word, but distributes the information transmitted bit simultaneously;

(b) remaining code source is distributed to the recommendation that its code source that has been assigned to does not reach the user, but and a minimum user of the information transmitted bit that has distributed;

(c) repeated execution of steps (b) has been assigned with up to all code sources, and perhaps the code source that has been assigned to of all users has all reached recommendation;

(d) code source still has residue after the recommendation if the code source that all active users have been assigned to has all reached, remaining code source is distributed to the maximum user of a CQI value, till the code source that code source is assigned or distributes to this user reaches its ability;

If there is a plurality of users' CQI value to equate, first execution in step (a) in these a plurality of users' set then, repeated execution of steps (b) has been assigned with up to all code sources again, and perhaps the code source that has been assigned to of all users has all reached till its ability.

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