CN100446617C - Access priority oriented queuing method under multi-frequency condition of TDD system - Google Patents

Abstract

The present invention relates to a method of accessing priority queuing of a TDD system under the condition of multiple frequency points. The method of the present invention is used for wireless resource allocation when RNC carries out the access of a user terminal according to queuing. The method comprises: a load factor of each frequency point in a subdistrict of the multiple frequency points is calculated, the accessing priority queuing of the frequency points is carried out according to the magnitude of the load factor of each frequency point, and the frequency point of which the load factor is minimum is the frequency point of which the accessing priority is maximum. In the accessing priority queuing of the frequency points, the magnitude of the load factor of each uplink time slot is calculated to each frequency point, and the accessing priority queuing of each uplink time slot is carried out; the uplink time slot of which the load factor is minimum is the uplink time slot of which the priority is maximum. In the accessing priority queuing of the frequency points, the magnitude of the load factor of each downlink time slot is calculated to each frequency point, and the accessing priority queuing of each downlink time slot is carried out; the downlink time slot of which the load factor is minimum is the downlink time slot of which the priority is maximum. Thus, the present invention obtains the priority queuing of the frequency points and the accessing priority queuing of the uplink time slot and the downlink time slot of each frequency point.

Description

Access priority queuing strategy under the tdd systems multifrequency point condition

Technical field

The present invention relates to the resource allocation methods under the realization multi-frequency-point community condition in time division duplex (TDD) cell mobile communication systems, specifically is a kind of method of access priority queuing.

Background technology

In order to satisfy the ever-increasing demand of mobile subscriber in the digital cellular mobile communication systems of future generation, use sectorization and multi-transceiver technology can reduce system in and disturb, and thereby the capacity of increase system.

Under the situation of single-carrier cell, a base station can cover several sectors, regard each the carrier wave zone in several sectors that the base station covered as independently logic district, radio network controller (RNC) can logic district be that unit carries out resource allocation just in RRM (RRM) algorithm.For example, cover the situation of 3 sectors, 3 carrier frequency for the base station, then thinking has 9 logic district, and the access control of RRM is to finish independently access operation at each logic district.Each logic district sends pilot broadcasts information separately.

The major advantage of cell sectorization is to have suppressed intersymbol interference, compare with the sub-district of non-sectorization, under the identical condition of number of users, the cell communication quality of sectorization will get a promotion, perhaps keeping under the situation of same systematic function, sectorization can increase the number of users that the sub-district holds.

Adopt after the multi-carrier district, regard each sector that the base station covered as independently logic district, but this logic district can comprise a plurality of carrier waves, can improve the resource utilization and the efficient of system like this.But it is more more complicated than the resource allocation under the single-carrier cell situation for the allocation of radio resources under the multi-carrier district situation, bring a lot of variations, but the resource allocation of multi-carrier district simultaneously then provides better condition and method for the utilance of improving resource owing to become more flexible.

Under the system architecture of multi-carrier district, at each sector, from N the frequency that is assigned to, determine one as main carrier frequency, in same sector, only on main carrier frequency, send downward guide time slot (DwPTS), up guide time slot (UpPTS) and broadcast message.Therefore, at the exploitation of existing protocol standard, need clearly indicate main carrier frequency, so that base station (NodeB) determines to send broadcast message on which frequency, and prior protocols need increase frequency point information in the message of channel configuration, so that terminal and NodeB obtain the information of related content.

Resource allocation function is one of RRM subject matter that will solve, and in order to improve the utilance of system wireless resource, when resource allocation, at first to solve the access priority queuing problem of resource allocation, priority height according to resource units such as frequency or time slot carries out successively then, thereby reasonably carries out wireless resource allocation.

The access priority queuing strategy of allocation of radio resources is the method that is primarily aimed under the single-carrier cell situation at present, such as the queuing strategy based on the time slot priority of resource and load, but the access priority queuing strategy of single-carrier cell can not directly be applied in the access priority queuing problem under the multifrequency point situation of sub-district.Because under the multi-frequency-point community situation, the calculating and the statistical method of lining up based on the access priority of resource or load are diverse, and the resource under the multi-frequency-point community condition or the computational methods of load will be complicated more and diversified.Thereby, line up for the access priority of multi-frequency-point community, particularly the access priority queuing strategy of the multi-frequency-point community under the tdd mode does not also have relevant realization technology at present.

Summary of the invention

The objective of the invention is to design the access priority queuing strategy under a kind of tdd systems multifrequency point condition, be in the TDD mobile communication system, the queuing strategy of the access priority under the condition of sub-district employing multifrequency point, result according to priority queueing carries out, and makes wireless resource allocation can reach very high resource utilization.

The technical scheme that realizes the object of the invention is: the access priority queuing strategy under a kind of tdd systems multifrequency point condition, and the allocation of radio resources when being used for the user terminal access comprises:

A. by formula $L_{\mathrm{dt}}=\frac{P_{\mathrm{dt}}}{\mathrm{\α}\·P_{\mathrm{MAX}}}$ Calculate the descending time slot stressor of each descending time slot on each frequency of multi-frequency-point community, L in the formula _DtThe descending time slot stressor of expression time slot t, P _DtThe expression base station is at the transmitting power sum of time slot t to all user terminals, P _MAXBe the maximum transmission power of base station, t=1 ..., Nd, Nd are the numbers of each frequency descending time slot, α is a system design parameters;

B. by formula $L_{{\mathrm{ut}}^{\′}}=\frac{P_{{\mathrm{ut}}^{\′}}}{\mathrm{\β}\·I_{\mathrm{th}}}$ Calculate the ascending time slot stressor of each ascending time slot on each frequency, L in the formula _{Ut '}The ascending time slot stressor of expression time slot t ', P _{Ut '}The gross power of all user terminals of the actual reception that the expression base station measures at time slot t ', I _ThBe the maximum interference that base station receiver can bear, t '=1 ...., Nu, Nu are the numbers of each frequency ascending time slot, β is a system design parameters;

C. according to the result of calculation of steps A and B, L by formula _f=ω L _Fu+ (1-ω) L _FdCalculate the stressor of each frequency, L in the formula _fThe stressor of expression frequency f, the value of weighted factor ω is 0＜ω＜1, L _FuExpression to Nu ascending time slot stressor of each frequency according to $L_{\mathrm{fu}}=\frac{1}{\mathrm{Nu}}\underset{t^{\′}=1}{\overset{\mathrm{Nu}}{\mathrm{\Σ}}}{L}_{{\mathrm{ut}}^{\′}}$ Ask the ascending time slot average load factor that obtains after the average treatment, L _FdExpression to Nd descending time slot stressor of each frequency according to $L_{\mathrm{fd}}=\frac{1}{\mathrm{Nd}}\underset{t=1}{\overset{\mathrm{Nd}}{\mathrm{\Σ}}}{L}_{\mathrm{dt}}$ Ask the descending time slot average load factor that obtains after the average treatment;

D. carry out the queuing of frequency access priority according to the stressor size of each frequency, the frequency of stressor minimum is the highest frequency of access priority.

Described weighted factor ω chooses the proportion that influences of the stressor of frequency f by ascending time slot stressor and descending time slot stressor.

Described system design parameters α is an empirical value of getting from the engineering design angle.

Described system design parameters β is an empirical value of getting from the engineering design angle.

This method also comprises: obtain descending time slot stressor and ascending time slot stressor that the highest frequency of described access priority obtains in described steps A and B, descending time slot stressor and ascending time slot stressor to the highest frequency of described access priority carry out priority queueing according to size respectively, the descending time slot of determining descending time slot stressor minimum is the highest descending time slot of access priority, and the ascending time slot of ascending time slot stressor minimum is the highest ascending time slot of access priority.

This method also comprises: when receiving radio resource request, in the highest frequency of described access priority, insert according to the size of the access priority of ascending time slot and descending time slot.

If on the highest frequency of described access priority, insert unsuccessful, then the access priority according to each frequency continues to adopt the method described in the claim 6 in proper order, begin one by one descending time slot stressor on each frequency and ascending time slot stressor to be carried out priority queueing according to size respectively from access priority time high frequency, and insert according to the access priority size of ascending time slot and descending time slot, until inserting successfully or all frequency, whole equal access failures of time slot.

The present invention is under the multi-frequency-point community situation, a kind of frequency resource access priority queuing strategy of proposition based on load, and part-frequency point priority queueing and two steps of time slot priority queueing carry out.In queuing, the computational methods of the uplink and downlink timeslot load on a frequency and the frequency resource access priority queuing strategy of loading have been used based on frequency.

The queuing of the access priority of frequency of the present invention is that each frequency to the sub-district carries out priority queueing, calculate the stressor of each frequency respectively according to algorithm of the present invention, according to the size of each frequency stressor frequency is ranked then, stressor is more little then high more to access priority that should frequency, otherwise priority is low more.The present invention carries out the access priority queuing to the time slot on each frequency, carry out respectively by uplink and downlink timeslot, time slot for up direction, size according to each ascending time slot stressor that calculates is ranked, the priority of more little then its ascending time slot of ascending time slot stressor is high more, according to the size of ascending time slot stressor the time slot priority of this frequency up direction is ranked; Same time slot for down direction, also rank according to the size of each descending time slot stressor that calculates, the priority of more little then its descending time slot of descending time slot stressor is high more, according to the size of descending time slot stressor the time slot priority of this frequency down direction is ranked.

Priority queueing of the present invention has taken into full account the characteristics of multi-frequency-point community, be Radio Resource when inserting frequency and the priority queueing of time slot, just can carry out allocation of radio resources then according to the priority of frequency and time slot.Compare with the wireless resource allocation methods of single-carrier cell, the allocation of radio resources of multi-carrier district is more flexible.The present invention propose in the TDD mobile communication system, adopt the solution of allocation of radio resources under the multi-carrier district condition, can improve the wireless resource utility efficiency of system.

Method of the present invention can be directly applied for the TD-SCDMA mobile communication system of multi-frequency-point community.

Description of drawings

Fig. 1 is based on the access priority queuing FB(flow block) of load.

Embodiment

What the present invention mainly solved is under the multi-frequency-point community situation, carries out the preceding frequency of access operation and the priority queuing method of time slot, and this access priority queuing is carried out in two steps, and the first step is carried out the frequency priority queueing, and second step was carried out the time slot priority queueing.

When the frequency priority queueing of carrying out the first step, be that the whole frequencies to each sub-district carry out priority queueing, the access priority height of each frequency resource is just lined up by access priority then in the algorithm computation sub-district that proposes by the present invention.

When carrying out the time slot priority queueing in second step, be on the frequency priority queueing basis that the first step is finished, can on the limit priority frequency, carry out the queuing of time slot priority earlier, press time slot priority queueing order then, select each time slot in this queuing to insert successively, until inserting successfully.If the time slot until lowest priority still can not successfully insert, then in the frequency priority queueing, select time high priority frequency, and on this time high priority frequency, carry out the time slot priority queueing, and press the time slot priority queueing in proper order, select each time slot in this queuing to insert successively, so, until inserting successfully.

When selecting time slot on selected frequency, each frequency carries out independently of one another, and up link (UL), down link (DL) time slot to a frequency carries out the access priority queuing respectively.

Wherein, the access priority of each frequency resource is based on just that the load condition of each frequency carries out in the calculation plot, and promptly the load condition according to each frequency sorts.Because the uplink and downlink load situation of each frequency more can directly reflect the operating position of current each frequency to resource, thereby the present invention judges the uplink and downlink load situation of each frequency respectively, and it is more reasonable to make load according to each frequency carry out the judgement of resource access priority.

The present invention also is based on the load of uplink and downlink time slot to the prioritization of the uplink and downlink time slot of each frequency, respectively the uplink and downlink time slot is carried out the access priority ordering.

Further specify technical scheme of the present invention below in conjunction with embodiment accompanying drawing 1.

Step 11, radio network controller receives the measurement report of node B about N each frequency of frequency point cell, comprise that node B is in the transmitting power sum (this value come from the transmitting carrier frequency power Transmitted carrierpower of Universal Terrestrial Radio Access Network UTRAN measurement report) of time slot t to all user terminals (UE), with the gross power (this value comes from the reception total wideband power RECEIVED TOTAL WIDE BAND POWER of UTRAN measurement report) of all user terminals (UE) that comprise this sub-district and adjacent sub-district that received, be 100ms the measuring period that forms this measurement report.

Step 12, radio network controller be according to measurement report, according to the following equation 1 and formula 2 calculate each descending time slot stressor of each frequency L respectively _DtWith each ascending time slot stressor L _UtAscending time slot adds up to Nu, descending time slot add up to Nd (ascending time slot sum Nu is symmetrical arranged or asymmetric setting with the total Nd visible system of descending time slot situation, but Nd and Nu sum are the system time gap sum, as to the TD-SCDMA system then time slot add up to 6).

To each descending time slot, make P _DtExpression node B is at the transmitting power sum of time slot t to all UE, then descending time slot stressor L _DtBe calculated as:

$L_{\mathrm{dt}}=\frac{P_{\mathrm{dt}}}{\mathrm{\α}\·P_{\mathrm{MAX}}},$ T=1 ..., Nd (formula 1)

Wherein, α is a system design parameters, can get an empirical value, P from engineering viewpoint _MAXIt is the maximum transmission power of Node B.The descending time slot stressor L that each frequency calculates _DtThere is Nd.

To each ascending time slot, make P _UtThe gross power of all UE of the actual reception that expression node B measures at time slot t supposes that the maximum interference that node B receiver can bear is I _Th(this is the upper limit of control ascending time slot load, is a definite value).The stressor L of ascending time slot then _UtBe calculated as:

$L_{\mathrm{ut}}=\frac{P_{\mathrm{ut}}}{\mathrm{\β}\·I_{\mathrm{th}}},$ T=1 ...., Nu (formula 2)

Wherein, β is a system design parameters, can get an empirical value from engineering viewpoint.The ascending time slot stressor L that each frequency calculates _UtThere is Nu.

Step 13, the ascending time slot stressor L of each frequency that utilization is calculated _UtAnd descending time slot stressor L _Dt, calculate each frequency ascending time slot average load factor L respectively according to formula 3 and formula 4 _Fu(to Nu ascending time slot stressor L _UtAsk average) and descending time slot average load factor L _Fd(to Nd descending time slot stressor L _DtAsk average).

The average load factor L of each frequency ascending time slot _FuFor:

$L_{\mathrm{fu}}=\frac{1}{\mathrm{Nu}}\underset{t=1}{\overset{\mathrm{Nu}}{\mathrm{\Σ}}}{L}_{\mathrm{ut}}$ (formula 3)

The average load factor L of each frequency descending time slot _FdFor:

$L_{\mathrm{fd}}=\frac{1}{\mathrm{Nd}}\underset{t=1}{\overset{\mathrm{Nd}}{\mathrm{\Σ}}}{L}_{\mathrm{dt}}$ (formula 4)

Step 14, the ascending time slot average load factor L of each frequency that utilization is calculated _FuWith descending time slot average load factor L _Fd, according to the stressor L of formula 5 each frequencies of calculating _f, f=1 ...., N.Calculate the stressor L of each frequency _f, should take all factors into consideration the average load of ascending time slot and descending time slot, and with this foundation as each frequency access priority queuing.

The stressor of each frequency is expressed as:

L _f=ω L _Fu+ (1-ω) L _Fd(formula 5)

Wherein, ω is the weighted factor of 0＜ω＜1, and expression ascending time slot stressor and descending time slot stressor are to the proportion that influences of frequency stressor.

Step 15 is according to each the frequency stressor L that is calculated _fThe size queuing, L _fThe access priority of more little then corresponding frequency is the highest, otherwise then priority is minimum.Thereby can select limit priority frequency f.

The operation of above-mentioned steps 11 to 15, finished the first step of the inventive method: the access priority to multi-frequency-point community carries out the frequency priority queueing.

Need to prove, in the above-mentioned most preferred embodiment, at the stressor L that calculates each frequency _fThe time, use be ascending time slot average load factor L _FuWith descending time slot average load factor L _Fd, also can omit step 13 during practical application, the ascending time slot stressor L that directly utilizes step 12 to obtain _UtAnd descending time slot stressor L _DtCalculate the stressor L of each frequency _fFor example according to certain principle from Nd descending time slot stressor L _DtIn get maximum or minimum value or median and replace L in the formula (5) _Fd, from Nu ascending time slot stressor L _UtIn get maximum or minimum value or median and replace L in the formula (5) _Fu

Step 16, the limit priority frequency f for step 11 is discharged to 15 operations according in the step 12, utilizes the descending time slot stressor L of this frequency f of formula 1 and formula 2 calculating _DtWith ascending time slot stressor L _UtSize, to L _DtAnd L _UtRank L respectively by size _DtThe access priority of more little this descending time slot is high more, otherwise then priority is low more; L _UtThe access priority of more little this ascending time slot is high more, otherwise then priority is low more, thereby determines the ascending time slot of limit priority and the descending time slot of limit priority.

Step 17 according to the operation and the record of step 16, when radio resource request, then is used in limit priority frequency f, the limit priority ascending time slot of selecting and limit priority descending time slot and inserts on this frequency f.Then select this frequency f high priority last time ascending time slot, inferior high priority descending time slot to insert if inserting gets nowhere, if can not insert always, the then operation of repeating step 16, the access priority of the uplink and downlink time slot on the inferior high priority frequency is ranked and according to priority inserted, until inserting successfully, perhaps all frequency, whole equal access failure of time slot then finish.The inventive method does not relate to the wireless resource allocation methods when inserting only at queuing.

Second step of the inventive method has been finished in the operation of above-mentioned steps 16: the access priority of multi-frequency-point community is carried out the priority queueing of uplink and downlink time slot.

In sum, the first step of the inventive method is that each frequency to multi-frequency-point community carries out priority queueing, with the stressor L of each frequency of calculating _fThe size queuing, L _fMinimum frequency f priority is the highest.Second step of the inventive method is according to the ascending time slot stressor L on each frequency (at first being the highest frequency of priority) _UtSize is ranked, L _UtThe priority of more little then this ascending time slot is the highest and according to the descending time slot stressor L on each frequency (at first being the highest frequency of priority) _DtSize is ranked, L _EtThe priority of more little then this descending time slot is the highest.Promptly for the time slot of up direction, each ascending time slot stressor L that calculates according to each frequency _UtSize successively the time slot priority of up direction is ranked; For the time slot of down direction, its queuing strategy is with up identical, according to each descending time slot stressor L of each frequency calculating equally _DtSize successively the time slot priority of down direction is ranked.

Owing to calculate the stressor L of each frequency in the first step _fThe time, be at the descending time slot average load factor L that calculates each frequency _FdAscending time slot average load factor L with each frequency _FuThe basis on do, and at the descending time slot average load factor L that calculates each frequency _FdAscending time slot average load factor L with each frequency _FuThe time, be again Nd descending time slot stressor L according to each frequency _DtNu ascending time slot stressor L with each frequency _UtCalculate to obtain, therefore when finishing second step of the present invention, only need Nd descending time slot stressor L of each frequency that the first step is calculated _DtThe queuing and to Nu ascending time slot stressor L _UtQueuing can be determined the descending time slot and the ascending time slot of high access priority, selects the descending time slot stressor L of limit priority frequency f _DtWith ascending time slot stressor L _UtInsert.

To each frequency in the queuing of frequency access priority and the queuing of each frequency uplink and downlink time slot, can carry out in the cycle, also can be that Event triggered is carried out,, also can before user terminal inserts, promptly perform queuing such as can when user terminal inserts distributing radio resource, carrying out.

Claims (7)

1. the access priority queuing strategy under the tdd systems multifrequency point condition, the allocation of radio resources when being used for user terminal and inserting is characterized in that comprising:

A. by formula $L_{\mathrm{dt}}=\frac{P_{\mathrm{dt}}}{\mathrm{\α}\·P_{\mathrm{MAX}}}$ Calculate the descending time slot stressor of each descending time slot on each frequency of multi-frequency-point community, L in the formula _DtThe descending time slot stressor of expression time slot t, P _DtThe expression base station is at the transmitting power sum of time slot t to all user terminals, P _MAXBe the maximum transmission power of base station, t=1 ..., Nd, Nd are the numbers of each frequency descending time slot, α is a system design parameters;

B. by formula $L_{{\mathrm{ut}}^{\′}}=\frac{P_{{\mathrm{ut}}^{\′}}}{\mathrm{\β}\·I_{\mathrm{th}}}$ Calculate the ascending time slot stressor of each ascending time slot on each frequency, L in the formula _{Ut '}The ascending time slot stressor of expression time slot t ', P _{Ut '}The gross power of all user terminals of the actual reception that the expression base station measures at time slot t ', I _ThBe the maximum interference that base station receiver can bear, t '=1 ...., Nu, Nu are the numbers of each frequency ascending time slot, β is a system design parameters;

C. according to the result of calculation of steps A and B, L by formula _f=ω L _Fu+ (1-ω) L _FdCalculate the stressor of each frequency, L in the formula _fThe stressor of expression frequency f, the value of weighted factor ω is 0＜ω＜1, L _FuExpression to Nu ascending time slot stressor of each frequency according to $I_{\mathrm{fu}}=\frac{1}{\mathrm{Nu}}\underset{t^{\′}=1}{\overset{\mathrm{Nu}}{\mathrm{\Σ}}}{L}_{u{t}^{\′}}$ Ask the ascending time slot average load factor that obtains after the average treatment, L _FdExpression to Nd descending time slot stressor of each frequency according to $L_{\mathrm{fd}}=\frac{1}{\mathrm{Nd}}\underset{t=1}{\overset{\mathrm{Nd}}{\mathrm{\Σ}}}{L}_{\mathrm{dt}}$ Ask the descending time slot average load factor that obtains after the average treatment;

D. carry out the queuing of frequency access priority according to the stressor size of each frequency, the frequency of stressor minimum is the highest frequency of access priority.

2. method according to claim 1 is characterized in that: described weighted factor ω chooses the proportion that influences of the stressor of frequency f by ascending time slot stressor and descending time slot stressor.

3. method according to claim 1 is characterized in that described system design parameters α is an empirical value of getting from the engineering design angle.

4. method according to claim 1 is characterized in that described system design parameters β is an empirical value of getting from the engineering design angle.

5, method according to claim 1, it is characterized in that, this method also comprises: obtain descending time slot stressor and ascending time slot stressor that the highest frequency of described access priority obtains in described steps A and B, descending time slot stressor and ascending time slot stressor to the highest frequency of described access priority carry out priority queueing according to size respectively, the descending time slot of determining descending time slot stressor minimum is the highest descending time slot of access priority, and the ascending time slot of ascending time slot stressor minimum is the highest ascending time slot of access priority.

6, method according to claim 5 is characterized in that, this method also comprises: when receiving radio resource request, in the highest frequency of described access priority, insert according to the size of the access priority of ascending time slot and descending time slot.

7, method according to claim 6, it is characterized in that, if on the highest frequency of described access priority, insert unsuccessful, then the access priority according to each frequency continues to adopt the method described in the claim 6 in proper order, begin one by one descending time slot stressor on each frequency and ascending time slot stressor to be carried out priority queueing according to size respectively from access priority time high frequency, and insert according to the access priority size of ascending time slot and descending time slot, until inserting successfully or all frequency, whole equal access failures of time slot.

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