CN100382464C

CN100382464C - TD-SCDMA system cell code word planning method and method for searching composite code word combination thereof

Info

Publication number: CN100382464C
Application number: CNB2004100487019A
Authority: CN
Inventors: 张孟; 冯心睿
Original assignee: Datang Mobile Communications Equipment Co Ltd
Current assignee: China Academy of Telecommunications Technology CATT
Priority date: 2004-06-10
Filing date: 2004-06-10
Publication date: 2008-04-16
Anticipated expiration: 2024-06-10
Also published as: CN1707973A

Abstract

The present invention discloses a planning method of the subzone code word of a TD-SCDMA system. Scrambling in the TD-SCDMA system is grouped according to whether strong relevancy exists in the scrambling or not, and the basic scrambling of the TD-SCDMA system and descending corresponding pilot-frequency code groups corresponding to the basic scrambling are obtained. When a network is planned, the descending pilot-frequency codes and the scrambling used in each subzone are distributed, and spread spectrum codes used in each subzone are distributed. In the method, when the TD-SCDMA networks at common frequency, strong interference which can occur among working code paths in adjacent subzones can be avoided, and the interference in the system is reduced. The present invention also discloses a method for searching the combinations of composite code words by using the TD-SCDMA system, when in the network planning, the optimal combination of the composite code words corresponding to the basic scrambling is searched by using a genetic algorithm according to the basic scrambling, and thus, the distribution of the scrambling used in each subzone and spread spectrum code paths is completed. When the network is planned, the optimal combination of the composite code words of the working code paths of each subzone is searched by the method, and meanwhile, the complexity of the dynamic distribution of the spread spectrum code during the running period of the system is reduced.

Description

TD-SCDMA system cell code word planing method and search for compound code word combined method

Technical field

The present invention relates to the distribution method of code word in code division multiple access (CDMA) mobile communication system, particularly a kind of Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) system cell code word planing method and search for compound code word combined method during the network planning.

Background technology

The 3rd third-generation mobile communication system has extensively adopted the access mode based on CDMA, and its essential characteristic is exactly to distinguish different users with different code words.In order to realize the beehive net structure, different cdma systems has all defined different separately code words and has used and allocative decision.

Wherein, the employed sign indicating number of TD-SCDMA system can be divided into by type: downlink frequency pilot code, ascending pilot frequency sign indicating number, cell scrambling, training sequence (midamble sign indicating number) and spreading code.The corresponding relation of downlink frequency pilot code, ascending pilot frequency sign indicating number, scrambler and basic midamble intersymbol is referring to table 1.

Table 1

As shown in table 1, downlink frequency pilot code one has 32, and ascending pilot frequency sign indicating number one has 256.The ascending pilot frequency sign indicating number is used in random access procedure by subscriber equipment (UE), and the employed downlink frequency pilot code of the ascending pilot frequency sign indicating number of each sub-district and sub-district has certain corresponding relation, corresponding 8 the ascending pilot frequency sign indicating numbers of downlink frequency pilot code.The quantity of scrambler and basic midamble sign indicating number all is 128, each sub-district is after downlink frequency pilot code is determined, can from 4 scramblers of each downlink frequency pilot code correspondence, select a scrambler as this sub-district, so also just determined simultaneously corresponding basic midamble sign indicating number, the midamble sign indicating number of different channels is to be produced according to certain skew by basic midamble sign indicating number in the sub-district.Spreading code is used to distinguish physical channels different in the same sub-district, and the midamble sign indicating number is used for each channel and carries out channel estimating.

Usually the distribution method of district code word is to be cell allocation downlink frequency pilot code (SYNC-DL) earlier, determines ascending pilot frequency sign indicating number, scrambler and basic midamble sign indicating number according to the relation between various code words shown in the table 1 then.Specifically, distribution to downlink frequency pilot code (SYNC-DL) can be according to certain multiplex mode, as 7 sub-districts is that one bunch or 19 sub-districts multiplex mode of being one bunch etc. carries out code assignment, then bunch expands according to such cell reuse in whole planning region.For example, when being one bunch for 19 sub-districts, by the sequence number of descending pilot tone, order is given 1-19 cell allocation descending pilot frequency respectively, after the downlink frequency pilot code of having determined the sub-district, just can determine the ID of all the other type codes according to the relation between various code words shown in the table 1 earlier.

Prior art when the network planning not the spreading code to the sub-district plan that but move dynamic assignment therebetween in system, the mode of distribution has multiple, wherein commonly used a kind of be to adopt the DCA algorithm to distribute.Spreading code is used to distinguish channels different in the same sub-district, the code channel so the distribution spreading code shares out the work exactly.Referring to Fig. 1, Fig. 1 is the schematic flow sheet of prior art DCA algorithm, and it mainly comprises following three steps:

Step 101 is ranked to channel priority, and the disturbed condition of the several code channels that may select for use in the same signal source is predicted and estimated, according to estimated result the disturbed condition of several code channels is carried out priority queueing again.

Step 102 is carried out channel according to priority and is selected, and the channel of selecting to be fit to is as candidate channel.

Step 103, channel adjustment is defined as the work code channel with selected channel.

Wherein, the disturbed condition of channel is predicted and estimated, the process of the disturbed condition of several code channels being carried out priority queueing according to estimated result more complicated when specific implementation again, and consume system resources relatively.

In the TD-SCDMA system, may there be strong correlation between the different composite code word.Work in neighbor cell if having two compound code words of strong correlation, if the subscriber signal strength ratio of the different districts of arrival receiver is more approaching, then these two users' signal will be difficult to be distinguished, and will cause relevant code track not work like this, thereby cause the loss of capacity.Although in practice, because diffusion of the time delay in the asynchronous and channel between the scrambler and the difference that arrives the different user signal path loss of receiver, this strong jamming meeting is by average and reduction, and the loss of this capacity is objective reality always.

In a word, because the strong correlation problem between the compound code word that existing district code word planing method is not considered to be combined by scrambler and spreading code, may produce the mutual bigger interference of neighbor cell work code channel in the real system, cause link performance deterioration, power system capacity to reduce, it is optimum that network configuration fails to reach.

Summary of the invention

In view of this, main purpose of the present invention is to provide a kind of TD-SCDMA system cell code word planning distribution method, and the mutual strong jamming of neighbor cell work code channel that may occur when avoiding the networking of TD-SCDMA system same frequency is disturbed in the reduction system.

Another main purpose of the present invention is to provide a kind of method of TD-SCDMA systematic search compound key combination, search out the optimum compound code word combination of each cell operation code channel when the network planning, the complexity and the system that is reduced in that reduce the optimum code word combination of search in the network planning process move the complexity of spreading code dynamic assignment therebetween.

Be an aspect that achieves the above object, the present invention proposes the district code word planing method of a kind of Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) system, whether this method exists strong correlation to divide into groups the basis of the scrambler in the TD-SCDMA system in advance each other, obtain the basic scrambler and the corresponding descending pilot frequency code character thereof of TD-SCDMA system, wherein, described basic scrambler is the scrambler in same scrambler grouping; In TD-SCDMA system network planning process, finish the distribution of sub-district base scrambler and spread spectrum code word, downlink frequency pilot code, and and then finish the distribution of cell scrambling and spread spectrum code word, its assigning process may further comprise the steps:

1) sets the work code channel number of each sub-district and optional code channel scope;

2) according to the work code channel number and the optional code channel scope of each sub-district of setting, utilize genetic algorithm to search out the compound code word combination of the basic scrambler of each sub-district optimum; Wherein, described compound code word is by scrambler with spreading code is compound constitutes;

3), determine the downlink frequency pilot code that use each sub-district according to the corresponding relation of basic scrambler and descending pilot frequency code character;

4) according to step 2) search out downlink frequency pilot code that the pairing basic scrambler of the compound code word combination of basic scrambler of each sub-district optimum and step 3) determine respectively with the TD-SCDMA system in the relation of each scrambler, determine the scrambler that use each sub-district;

5) according to step 2) compound code word combination, the step 2 of the basic scrambler of the optimum that searches out) the compound code word that basic scrambler constituted of compound code word combination correspondence of basic scrambler of optimum of each sub-district of searching out and the mutual corresponding relation of compound code word that each employed scrambler in sub-district that step 4) is determined is constituted, determine the spreading code that use each sub-district.

Wherein, this method process of obtaining basic scrambler and corresponding descending pilot frequency code character thereof in advance can may further comprise the steps:

Steps A: each scrambler in the TD-SCDMA system and each orthogonal variable spreading factor sign indicating number are formed compound key respectively, and the compound key of each scrambler and the compound key of another scrambler are carried out correlation calculations in twos;

Step B: according to the result of calculation of the correlation calculations of steps A:

Judge that the cross-correlation mould value that whether has compound key between the compound key is the 16 correlation forms of expression that showed, if, then this is existed the correlation form of expression two compound keys corresponding respectively scrambler be divided in the scrambler grouping with same equivalent relation, according to as upper type, the scrambler that will meet this Rule of judgment is divided in the same scrambler grouping;

Step C: the scrambler grouping that utilizes step B to obtain, and code character grouping scheme in the TD-SCDMA system specifications, downlink frequency pilot code is divided into groups again, divide the result thereby obtain new code word, this code word is divided among the result, and each in this scrambler grouping is organized corresponding one group of downlink frequency pilot code.

Described step C can comprise:

Step C1: from each different scramblers grouping, select scrambler, constitute the scrambler base by the basic scrambler of selecting as basic scrambler; Wherein, the scrambler of described selection belongs to the different scrambling codes code character in the TD-SCDMA system specifications respectively;

Step C2: by determined scrambler base downlink frequency pilot code is divided into groups again, divide the result, the corresponding one group of downlink frequency pilot code of each basic scrambler thereby obtain new code word.

Step C1 can comprise:

Step C11: as first group, from this first group, select a scrambler as basic scrambler with a described scrambler grouping with same equivalent relation;

Step C12: divide into groups as second group with another scrambler with same equivalent relation, from this second group, select another scrambler as basic scrambler, wherein, this another scrambler is different from this scrambler among the described step C11, and with step C11 in this scrambler belong to different scrambler code character in the TD-SCDMA system specifications respectively; According to this step, from 12 scrambler groupings, select a basic scrambler respectively, form the scrambler base.

Scrambler of described selection can comprise as basic scrambler:

Step C121: from a code character that is different from the own code character of selecting, select a scrambler;

Step C122: judge that whether this selected scrambler and the scrambler selected be two scramblers in the same scrambler code character in the TD-SCDMA system specifications grouping scheme, if, then return step C121, in step C121, reselect a new scrambler in the current selected code character, otherwise, execution in step C123;

Step C123: with selected scrambler as described basic scrambler.

In step C12, if in this second group, can't find with step C11 in selected this scrambler belong to the scrambler of the different scrambler code character in the grouping scheme of TD-SCDMA system specifications respectively, then this method may further include:

Return step C11, in first group described in the step C11, select new scrambler and then execution in step C12.

Step C2 can comprise:

Step C21: each the basic scrambler in the scrambler base that constitutes described in the step C1 is identified, and each basic scrambler has unique separately identifier respectively;

Step C22: to be the determined identifier of each basic scrambler among the step C21, identify the scrambler grouping that this each basic scrambler originally belonged to, thereby obtain scrambler grouping based on basic scrambler;

Step C23:, adopt each scrambler in the grouping of basic scrambler identifier sign time-division-synchronization code multi-address division system scrambler according to the scrambler grouping of step C22 based on basic scrambler;

Step C24: based among the step C23 to the sign again of scrambler, search pairing all downlink frequency pilot code of each basic scrambler sign respectively, then, divide into groups based on basic scrambler, obtain the downlink frequency pilot code of each basic scrambler correspondence, divide the result thereby realize obtaining new code word.

Step C can comprise:

Each group in the scrambler grouping that obtains among the identification of steps B respectively, each group has unique separately identifier respectively, according to the group result after the sign, and with reference to the corresponding relation between scrambler and the downlink frequency pilot code in the TD-SCDMA system specifications, determine to obtain scrambler that each identifier the identifies pairing downlink frequency pilot code of dividing into groups, divide the result thereby obtain new code word.

The work code channel number of each sub-district of the described setting of step 1) and optionally the method for code channel scope can be the work code channel number of setting each sub-district by traffic forecast; Then, according to the 3GPP criterion that selection is used about code channel, determine optional code channel scope.

Described step 2) can may further comprise the steps:

21) according to the work code channel number and the optional code channel scope configuration spreading code of each sub-district of setting, the configuration of basic scrambler and spreading code is made up with the individuality sign of biradical because of representative, and the generating unit group collaborations is the individuality of initial population at random;

22) each individuality in the colony is carried out at the fitness assessment of disturbing;

23) fitness individual according to described each that assess out selects to participate in the individuality of heredity;

24) the basic scrambler gene of selecting to participate in the hereditary individuality is in twos carried out the individuality intersection, generate new individuality, wherein, described basic scrambler gene is the monobasic gene that the basic scrambler of all sub-districts uses constitutes;

25) the spreading code gene of selecting to participate in the hereditary individuality is carried out individual variation, generate colony of future generation, wherein, described spreading code gene is the monobasic gene that the spreading code of sub-district use constitutes;

26) return execution in step 22 according to predetermined condition) or stop genetic iteration;

27) after genetic iteration stops,, determine that then this individuality is the compound code word combination of the basic scrambler of this sub-district optimum if all individualities of the colony of future generation that obtains are identical.

Described step 21) further comprise the gene code method, this method can for:

Adopt the array sequence to represent basic scrambler gene, each element sequence number of array is the sub-district sequence number, and element value is the employed basic scrambler of respective cell; Adopt binary matrix notation spreading code gene, the matrix line number is total number of cells, and the row sequence number is corresponding with the sub-district sequence number; 16 binary values of every row storage, the behaviour in service of 16 spread spectrum code channels of expression.

Described step 22) can may further comprise the steps:

211) calculate individual penalty value;

Penalty value comprises: total stack of the interference that a, all code channels bore, the first of formation penalty value; B, the code channel that exceeds interference threshold is appended punishment, constitute the second portion of penalty value; C, set each sub-district and allow the code channel quantity thresholding that bears large disturbance that occurs, punishment is appended in the sub-district that exceeds this thresholding in the individuality, constitute the third part of penalty value;

212) calculate the ideal adaptation degree with following formula:

fitness＝Penalty_Max-Penalty_indi+C

Wherein, fitness is the fitness of single individuality; Penalty_indi is the penalty value of single individuality; Penalty_Max is an individual penalty value maximum in the generation colony; C is a constant, and its selection should be satisfied all individualities and all have the selected condition that participates in the probability of heredity.

Described penalty value can also comprise:

D, calculate each code channel and bear standard deviation or the variance of disturbing size, in view of the above individuality is appended punishment, it is big that big individual corresponding of variance appended punishment, the 4th part of formation penalty value.

Described step 212) may further include:

Initial several generations colony ideal adaptation degree is done the mathematics conversion, make ideal adaptation degree difference reduce;

Ideal adaptation degree to last several generations colony is done the mathematics conversion, increases the difference of ideal adaptation degree.

Step 23) method of the individuality of described selection participation heredity can may further comprise the steps:

231) summation of all ideal adaptation degree in the calculating colony: fitness_total=∑ fitness_i,

Wherein fitness_i represents i individual fitness;

232) calculate each individual selecteed probability in the colony

Probability P _ i=fitness_i/fitness_total,

Wherein P_i represents i individual selected probability;

233) select the individual genetic manipulation that participates in according to the selected probability of individuality.

Step 24) described individual method of intersecting can for: adopt single-point, or multiple spot to intersect the intersection of finishing basic scrambler gene at 2.

Described step 24) may further include: judge whether the new individuality that is produced violates predefined constraints,, redistribute basic scrambler and selection spreading code then for this sub-district if violate constraints.

Step 25) method of described individual variation can for:

To bear the code channel of maximum interference in certain probability P selection individuality, this code channel is implemented mutation operation; Perhaps finish the code channel variation with the non-code channel that bears maximum interference in the probability 1-P selection individuality.

Step 25) described mutation process can be done the binary value negate for the spreading code gene in the individuality that described selection is participated in heredity.

Described step 26) can be the termination number of times of predetermined genetic iteration,, otherwise return execution in step 22) if the number of times of genetic iteration reaches and stops number of times then stop genetic iteration;

Perhaps, order or hot key that the control iteration of setting stops, this termination is ordered or hot key is pressed if received, and then stops genetic iteration; Otherwise return execution in step 22).

Step 3) is described determine the downlink frequency pilot code that use each sub-district method can for:

Determine basic scrambler earlier,, determine the downlink frequency pilot code that use each sub-district then by the pairing descending pilot frequency code character of basic scrambler; To arbitrary sub-district, the downlink frequency pilot code of being distributed must belong to the pairing descending pilot frequency code character of its basic scrambler; Any different basic scrambler and downlink frequency pilot code of neighbor cell allocation.

The method of the spreading code that use the described definite sub-district of step 5) can may further comprise the steps:

51) correlation between the compound key sub-block of the compound key sub-block of the basic scrambler formation of calculation plot use and the scrambler formation that step 4) is determined;

52) finding step 51) described in the form that constitutes of correlation, obtain the spreading code of the scrambler correspondence of sub-district use, wherein, the spreading code and step 2 of the scrambler correspondence used of described sub-district) the corresponding spreading code of compound code word of optimal base scrambler of acquisition has equivalence relation.

According to another aspect of above-mentioned purpose, the invention provides a kind of method of TD-SCDMA systematic search compound key combination, this method may further comprise the steps:

1) according to the work code channel number and the optional code channel scope configuration spreading code of each sub-district of setting, the configuration of basic scrambler and spreading code is made up with the individuality sign of biradical because of representative, and the generating unit group collaborations is the individuality of initial population at random;

2) each individuality in the colony is carried out at the fitness assessment of disturbing;

3) fitness individual according to described each that assess out selects to participate in the individuality of heredity;

4) the basic scrambler gene of selecting to participate in the hereditary individuality is in twos carried out the individuality intersection, generate new individuality, wherein, described basic scrambler gene is the monobasic gene that the basic scrambler of all sub-districts uses constitutes;

5) the spreading code gene of selecting to participate in the hereditary individuality is carried out individual variation, generate colony of future generation, wherein, described spreading code gene is the monobasic gene that the spreading code of sub-district use constitutes;

6) return execution in step 2 according to predetermined condition) or stop genetic iteration;

7) after genetic iteration stops,, determine that then this individuality is the compound code word combination of the basic scrambler of this sub-district optimum if all individualities of the colony of future generation that obtains are identical.

Described step 1) further comprises the gene code method, this method can for:

Described step 2) can may further comprise the steps:

21) calculate individual penalty value;

22) calculate the ideal adaptation degree with following formula:

fitness＝Penalty_Max-Penalty_indi+C

Wherein, fitness is the fitness of single individuality; Penalty_indi is the penalty value of single individuality; Penalty_Max is an individual penalty value maximum in the generation colony; C is a constant, and the selection of C value should be satisfied all individualities and all have the selected condition that participates in the probability of heredity.

Described penalty value can also comprise:

Described step 22) may further include:

The method that the described selection of step 3) participates in the individuality of heredity can may further comprise the steps:

31) summation of all ideal adaptation degree in the calculating colony: fitness_total=∑ fitness_i,

Wherein fitness_i represents i individual fitness;

32) calculate each individual selecteed probability in the colony

Probability P _ i=fitness_i/fitness_total,

Wherein P_i represents i individual selected probability;

33) select the individual genetic manipulation that participates in according to the selected probability of individuality.

The described individual method of intersecting of step 4) can for: adopt single-point, or multiple spot to intersect the intersection of finishing basic scrambler gene at 2.

Described step 4) may further include: judge whether the new individuality that is produced violates predefined constraints, if violate constraints, redistribute basic scrambler and selection spreading code then for this sub-district.

The method of the described individual variation of step 5) can for:

The described mutation process of step 5) can be done the binary value negate for the spreading code gene in the individuality that described selection is participated in heredity.

Described step 6) can be the termination number of times of predetermined genetic iteration, if the number of times of genetic iteration reaches and stops number of times then stop genetic iteration, otherwise returns execution in step 2);

Perhaps, order or hot key that the control iteration stops are set, this termination is ordered or hot key is pressed if received, and then stops genetic iteration; Otherwise return execution in step 2).

As seen from the above technical solutions, the district code word planing method of this TD-SCDMA of the present invention system, whether exist strong correlation to divide into groups each other the basis of the scrambler in the TD-SCDMA system in advance, obtain the basic scrambler and the corresponding descending pilot frequency code character thereof of TD-SCDMA system; When the network planning, set the work code channel number and the optional code channel scope of each sub-district earlier; According to the work code channel number and the optional code channel scope of each sub-district of setting, utilize the compound code word combination of the optimum basic scrambler of genetic algorithm search again; Downlink frequency pilot code, scrambler that the present invention not only distributes each sub-district to use when the network planning, and the spreading code that distributes each sub-district to use.Whole process realizes based on basic scrambler, whether the base scrambler is according to existing strong correlation to divide into groups to obtain each other, therefore, the mutual strong jamming of neighbor cell work code channel that the inventive method may occur in the time of can avoiding the networking of TD-SCDMA system same frequency is disturbed in the reduction system.

The method of the compound code word combination of this TD-SCDMA systematic search of the present invention according to basic scrambler, utilizes genetic algorithm to search out the compound code word combination of basic scrambler of the optimum of each cell operation code channel when the network planning, uses for each sub-district operation; Simultaneously, the compound code word combination of these optimums can store, and the dynamic assignment of system's spreading code in service only need therefrom read suitable spreading code, is reduced in the complexity of system's run duration spreading code dynamic assignment.

Description of drawings

Fig. 1 is the schematic flow sheet of prior art DCA algorithm;

Fig. 2 is the schematic flow sheet of district code word planing method of the present invention;

The flow chart that Fig. 3 divides into groups to scrambler for the present invention;

Fig. 4 is for realizing the flow chart of step 303 among Fig. 3;

Fig. 5 is 3 cell reuse structural representations;

Fig. 6 searches for the flow chart of a preferred embodiment of method of compound key for the present invention;

Fig. 7 is after using district code word planing method of the present invention, the schematic flow sheet of DCA algorithm.

Embodiment

For making purpose of the present invention, technical scheme and advantage clearer, below with reference to the accompanying drawing embodiment that develops simultaneously, the present invention is described in more detail.

The district code word planing method of this TD-SCDMA of the present invention system, in advance with 128 scramblers in the TD-SCDMA system according to whether existing strong correlation to divide into groups each other, obtain the basic scrambler and the corresponding descending pilot frequency code character thereof of TD-SCDMA system; Finish the distribution of each cell downlink pilot code, scrambler and spread spectrum code word when the network planning, referring to Fig. 2, Fig. 2 is the schematic flow sheet of district code word planing method of the present invention.This allocation flow may further comprise the steps:

Step 201 is set the work code channel number of each sub-district and optional code channel scope.The work code channel number of determining each sub-district is promptly determined the expection capacity of sub-district by traffic forecast.The prediction work code channel number is to be system works best performance in the long time herein.After determining the work code channel number,, determine optional code channel scope according to the 3GPP criterion that selection is used about code channel.

Step 202, utilize genetic algorithm to search out the compound code word combination of each sub-district according to this work code channel number and optional code channel scope based on the optimum of basic scrambler, just scrambler and the spreading code that the sub-district is used planned, finds out the configuration combination of the basic scrambler and the spreading code of each sub-district.

This step can be used the method for TD-SCDMA systematic search compound key provided by the invention, and the grouping of basic scrambler and corresponding downlink frequency pilot code thereof is realized as constraints.This method utilizes genetic algorithm to realize, this method is elaborated when specifying step 202 following again.

Step 203 according to the corresponding grouping relation of basic scrambler with downlink frequency pilot code, is determined the downlink frequency pilot code that use each sub-district.

Step 204, the relation of each code word is determined the scrambler that use the sub-district in the basic scrambler of determining according to step 202 and downlink frequency pilot code and the TD-SCDMA system;

Step 205, the scrambler that basic scrambler that the spreading code of the compound key correspondence of the basic scrambler of the optimum that searches out according to step 202, step 202 are determined and step 204 are determined is determined the spreading code that use the sub-district.

Whether below at first exist strong correlation to divide into groups each other to the scrambler basis, the method that obtains the descending pilot frequency code character of basic scrambler and correspondence thereof is elaborated.

This method is based on that following analysis carries out:

The scrambler of TD-SCDMA system is 128, makes up by the spreading code with 16 SF=16, can obtain 2048 compound keys altogether.Cross correlation between these compound keys has nothing in common with each other, through discovering, under the situation of considering the channel delay diffusion fully synchronously and not, cross correlation value between the compound key (absolute value) has four kinds of situations such as 0,4,8,16, and one of form of expression of the their cross correlation between the compound key sub-block that different scramblers is formed with spreading code is as shown in table 2.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	1	0	0	0	0	0	0	0	0	0	0	0	16	0	0	0	0
2	0	0	0	0	0	0	0	0	0	0	16	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	16	0	0	0	0
2	0	0	0	0	0	0	0	0	0	0	16	0	0	0	0	0	3	0	0	0	0	0	0	0	0	0	16	0	0	0	0	0	0
4	0	0	0	0	0	0	0	0	16	0	0	0	0	0	0	0	3	0	0	0	0	0	0	0	0	0	16	0	0	0	0	0	0
4	0	0	0	0	0	0	0	0	16	0	0	0	0	0	0	0	5	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	16
6	0	0	0	0	0	0	0	0	0	0	0	0	0	0	16	0	5	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	16
6	0	0	0	0	0	0	0	0	0	0	0	0	0	0	16	0	7	0	0	0	0	0	0	0	0	0	0	0	0	0	16	0	0
8	0	0	0	0	0	0	0	0	0	0	0	0	16	0	0	0	7	0	0	0	0	0	0	0	0	0	0	0	0	0	16	0	0
8	0	0	0	0	0	0	0	0	0	0	0	0	16	0	0	0	9	0	0	0	16	0	0	0	0	0	0	0	0	0	0	0	0
10	0	0	16	0	0	0	0	0	0	0	0	0	0	0	0	0	9	0	0	0	16	0	0	0	0	0	0	0	0	0	0	0	0
10	0	0	16	0	0	0	0	0	0	0	0	0	0	0	0	0	11	0	16	0	0	0	0	0	0	0	0	0	0	0	0	0	0
12	16	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	11	0	16	0	0	0	0	0	0	0	0	0	0	0	0	0	0
12	16	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	13	0	0	0	0	0	0	0	16	0	0	0	0	0	0	0	0
14	0	0	0	0	0	0	16	0	0	0	0	0	0	0	0	0	13	0	0	0	0	0	0	0	16	0	0	0	0	0	0	0	0
14	0	0	0	0	0	0	16	0	0	0	0	0	0	0	0	0	15	0	0	0	0	0	16	0	0	0	0	0	0	0	0	0	0
16	0	0	0	0	16	0	0	0	0	0	0	0	0	0	0	0	15	0	0	0	0	0	16	0	0	0	0	0	0	0	0	0	0

Table 2

In table 2, the spreading code of 16 SF=16 of a scrambler of laterally expression correspondence in the form, the spreading code of 16 SF=16 of another scrambler of vertically expression correspondence, value in the form is exactly the cross correlation value of the compound key sub-block formed with the OVSF spreading code of SF=16 respectively of two scramblers, computational methods are that the cross correlation value that obtains respectively in 16 chip is sued for peace, and therefore peaked absolute value is 16.The position of above-mentioned characteristic value appears in the compound key cross correlation value between different scrambling codes in table 2 can be different, the feature that the position that is occurred does not influence this table 2 is embodied, the feature that table 2 embodied can reduce: all having a cross-correlation mould value in each row or each row in the table is 16, and other 15 cross-correlation mould values are 0;

Cross-correlation mould value occurring is 16 expressions: laterally have the equivalence feature between the compound code word that the compound code word of scrambler and spreading code formation and vertical scrambler and spreading code constitute; If neighbor cell has distributed the scrambler with their cross correlation shown in the table 2 respectively, has strong correlation between the compound key sub-block that this scrambler and spreading code was composited, because this strong correlation, then all there is the channel code with strong correlation in each channel code in sub-district in neighbor cell, causes the loss of power system capacity.

Referring to Fig. 3, the flow chart that Fig. 3 divides into groups to scrambler for the present invention.This flow process may further comprise the steps:

Step 301: the scrambler in the TD-SCDMA system is all carried out correlation calculations, each scrambler is divided into different scrambler groupings according to the correlative relationship that its compound key had, and resulting scrambler grouping is called the scrambler grouping with same equivalent relation in this step;

Step 302: according to resulting scrambler grouping in step 301, from this code character, select basic scrambler, constitute the scrambler base by the basic scrambler of selecting with same equivalent relation;

Step 303: by determined scrambler base downlink frequency pilot code is divided into groups again, thereby obtain new code word group result.

Obtain basic scrambler in the present embodiment earlier, and then determine the downlink frequency pilot code that each basic scrambler is corresponding with the relation of downlink frequency pilot code according to scrambler, thereby obtain new code word group result, utilize this group result can simplify calculating: in the network planning, utilize this group result, only need carry out network planning calculating, and need not carry out the calculating of the network planning at 128 scramblers based on 12 basic scramblers.

Be appreciated that and also can directly utilize the scrambler grouping that obtains in the step 301, calculate, determine to carry out again after employed scrambler divides into groups the distribution of downlink frequency pilot code based on 12 scrambler grouping carrying out network plannings.So just do not need to judge basic scrambler and obtain the scrambler base that code assignment is carried out in the scrambler grouping with same equivalent relation that directly obtains according to the present invention.

Below the specific implementation of above step is described in detail respectively:

One, the specific implementation of step 301:

After scrambler in the TD-SCDMA system all carried out correlation calculations, can be met that as above table 2 showed, compound key cross-correlation mould value exists for the scrambler grouping of 16 situation, this grouping as

Shown in the table 3:

0 4 25 26 28 29 33 39 41 42 48 52 54 56 84 89
0 4 25 26 28 29 33 39 41 42 48 52 54 56 84 89	1 5 7 10 15 20 40 46 47 49 61 64 75 82 118 126
2 3 6 11 12 17 22 23 34 35 36 38 45 50 65 86	1 5 7 10 15 20 40 46 47 49 61 64 75 82 118 126
2 3 6 11 12 17 22 23 34 35 36 38 45 50 65 86	8 9 13 14 18 19 24 27 32 37 44 67 70 104 116 117
16 21 30 31 43 59 78 85 92 94 99 105 107 109 124 125	8 9 13 14 18 19 24 27 32 37 44 67 70 104 116 117
16 21 30 31 43 59 78 85 92 94 99 105 107 109 124 125	51 58 102 127
53 80 91 100 120	51 58 102 127
53 80 91 100 120	55 60 71 83 87 112 115

57 77 81 88 96 97 101
57 77 81 88 96 97 101	62 68 69 76 108 122
63 66 72 79 93 95 106 110 113 123	62 68 69 76 108 122
63 66 72 79 93 95 106 110 113 123	73 74 90 98 103 111 114 119 121

Table 3

Referring to table 3, the correlation form of expression between the compound key sub-block that any two scramblers in this table in each row constitute and the form of expression shown in the table 2 are equal to, and have the relation of same equivalence in twos between the scrambler;

Two, the specific implementation of step 302:

Referring to table 2 and table 3, the correlation in the table 3 between the compound key sub-block of any two scrambler correspondences of every row can be equal to the correlation form of expression shown in the table 2.Studies show that, any two scramblers of the every row of table 3 have the characteristic that mutual equivalence characterizes, based on this discovery, select the basic scrambler of one group of scrambler of TD-SCDMA system as the TD-SCDMA system, constitute the scrambler base of TD-SCDMA system by basic scrambler, the scrambler of TD-SCDMA system all can be characterized by certain basic scrambler equivalence, and the selection criterion of basic scrambler is as follows:

(1) every row of table 3 has and has only a scrambler as basic scrambler; The reason of working out this criterion is that being unlikely to occur selected basic scrambler has equivalent relation each other, thereby brings the correlation influence;

(2) any two basic scramblers can not belong to the same scrambler code character of the scheme of grouping shown in the table 1; The reason of formulating this criterion is: this grouping scheme should guarantee that the DwPTS of neighbor cell in network planning process differs from one another;

Based on as above criterion, performing step 302 specifically may further comprise the steps:

Step 3021: as first group, from this first group, select a scrambler a as basic scrambler with a group of determined scrambler grouping with same equivalent relation in the step 301;

Step 3022: with this have same equivalent relation scrambler grouping be different from another code character of first group as second group, from this second group, select another scrambler b, carry out then and judge: judge whether a selected scrambler a belongs to two interior scramblers of the same scrambler code character shown in the table 1 in this selected another scrambler b and the step 3021, if, then return this step, in this second group, reselect a new scrambler, until in second group, finding the scrambler that meets Rule of judgment as a basic scrambler; Otherwise, according to this step, from 12 scrambler groupings, select a basic scrambler respectively, form the scrambler base.

Wherein, being judged as that this step is carried out embodies the step that aforesaid basic scrambler selection criterion is carried out, if in this step, each scrambler in this second group is through after the aforesaid judgement, all do not obtain meeting the scrambler of this criterion, then return step 3021, reselect a scrambler, and then execution in step 3022 and subsequent step thereof.

In the present invention, also can further repeat above-mentioned steps 302, thereby select at least two scrambler bases that differ from one another.

Be example with table 3 below, specify the implementation procedure of step 302 with a specific embodiment:

In this specific embodiment, performing step 302 needs following steps:

1, select certain scrambler a as basic scrambler by first row of table 3;

2, select certain scrambler b as basic scrambler at the next line of table 3, require this base scrambler and other arbitrary basic scramblers of having selected all not to be subordinated in the 3GPP standard grouping scheme same group;

3,, return lastrow and select new scrambler as basic scrambler if fail to find qualified scrambler in the step 2; Otherwise execution in step 4;

4, execution in step 2～3, up to finding 12 scramblers that meet basic scrambler selection criterion as basic scrambler, and constitute the scrambler bases with these 12 basic scramblers.

According to as above step, present embodiment is selected 12 basic scramblers, the scrambler base shown in being constructed as follows:

{0，5，11，13，16，51，53，57，60，66，68，73}

In other embodiment of the present invention, also can select other scrambler base according to as above step 302, scrambler base shown here only is descriptive, and should not think that this scrambler base defines protection scope of the present invention;

Three, the realization of step 303: referring to Fig. 4, Fig. 4 is for realizing the flow chart of step 303 among Fig. 3.This flow process may further comprise the steps:

Step 3031 identifies each the basic scrambler in the selected scrambler base in the step 302, and each basic scrambler has unique separately identifier respectively; Referring to table 4, in the embodiment of the invention, adopt A～L that basic scrambler is identified, the corresponding relation ginseng is shown in Table 4:

A	B	C	D	E	F	G	H	I	J	K	L
A	B	C	D	E	F	G	H	I	J	K	L	0	5	11	13	16	51	53	60	57	68	66	73

Table 4

Wherein, in other embodiment of the present invention, also can adopt other identifier to carry out above-mentioned sign, not influence realization of the present invention;

Step 3032 to be the determined identifier of each basic scrambler in the step 3031, identifies the scrambler code character that this each basic scrambler originally belonged to, thereby obtains the scrambler grouping based on basic scrambler; In embodiments of the present invention, this group result is as shown in table 5;

A	0 4 25 26 28 29 33 39 41 42 48 52 54 56 84 89
A	0 4 25 26 28 29 33 39 41 42 48 52 54 56 84 89	B	1 5 7 10 15 20 40 46 47 49 61 64 75 82 118 126
C	2 3 6 11 12 17 22 23 34 35 36 38 45 50 65 86	B	1 5 7 10 15 20 40 46 47 49 61 64 75 82 118 126
C	2 3 6 11 12 17 22 23 34 35 36 38 45 50 65 86	D	8 9 13 14 18 19 24 27 32 37 44 67 70 104 116 117
E	16 21 30 31 43 59 78 85 92 94 99 105 107 109 124 125	D	8 9 13 14 18 19 24 27 32 37 44 67 70 104 116 117
E	16 21 30 31 43 59 78 85 92 94 99 105 107 109 124 125	F	51 58 102 127
G	53 80 91 100 120	F	51 58 102 127
G	53 80 91 100 120	H	55 60 71 83 87 112 115
I	57 77 81 88 96 97 101	H	55 60 71 83 87 112 115
I	57 77 81 88 96 97 101	J	62 68 69 76 108 122
K	63 66 72 79 93 95 106 110 113 123	J	62 68 69 76 108 122
K	63 66 72 79 93 95 106 110 113 123	L	73 74 90 98 103 111 114 119 121

Table 5

Step 3033 according to the scrambler grouping of step 3032 based on basic scrambler, adopts each scrambler in 32 scrambler groupings of basic scrambler identifier sign TD-SCDMA system; For example, basic scrambler identifier A, B, C, the C in 0,1,2, the 3 difference correspondence table 5 of the scrambler in the scrambler group 1.In embodiments of the present invention, sign result ginseng is shown in Table 6;

1	A	B	C	C
1	A	B	C	C	2	A	B	C	B
3	D	D	B	C	2	A	B	C	B
3	D	D	B	C	4	C	D	D	B
5	E	C	D	D	4	C	D	D	B
5	E	C	D	D	6	B	E	C	C
7	D	A	A	D	6	B	E	C	C
7	D	A	A	D	8	A	A	E	E
9	D	A	C	C	8	A	A	E	E
9	D	A	C	C	10	C	D	C	A
11	B	A	A	E	10	C	D	C	A
11	B	A	A	E	12	D	C	B	B

13	A	B	C	F
13	A	B	C	F	14	A	G	A	H
15	A	I	F	E	14	A	G	A	H
15	A	I	F	E	16	H	B	J	K
17	B	C	K	D	16	H	B	J	K
17	B	C	K	D	18	J	J	D	H
19	K	L	L	B	18	J	J	D	H
19	K	L	L	B	20	J	I	E	K
21	G	I	B	H	20	J	I	E	K
21	G	I	B	H	22	A	E	C	H
23	I	A	L	G	22	A	E	C	H
23	I	A	L	G	24	E	K	E	K
25	I	I	L	E	24	E	K	E	K
25	I	I	L	E	26	G	I	F	L
27	D	E	K	E	26	G	I	F	L
27	D	E	K	E	28	J	E	K	L
29	H	K	L	H	28	J	E	K	L
29	H	K	L	H	30	D	D	B	L
31	G	L	J	K	30	D	D	B	L
31	G	L	J	K	32	E	E	B	F

Table 6

Step 3034, based in the step 3033 to the sign again of scrambler, search pairing all downlink frequency pilot code of each basic scrambler sign respectively, then, divide into groups based on basic scrambler, obtain the downlink frequency pilot code of each basic scrambler correspondence, thereby realize obtaining new code word group result; Particularly, find in the table 6 scrambler at each basic scrambler sign place earlier, as A in

scrambler

1,2,7-11,13-15,22,23.0,1,6-10,12-14,21,22 then according to TD-SCDMA system table 1, the downlink frequency pilot code of above-mentioned scrambler correspondence is assigned to a group of this base scrambler sign, as the downlink frequency pilot code of

scrambler

1,2,7-11,13-15,22,23 correspondences be:.In embodiments of the present invention, new group result is as shown in table 7;

The base scrambler	DwPTS
The base scrambler	DwPTS	A	0 1 6 7 8 9 10 12 13 14 21 22
B	0 1 2 3 5 10 11 12 15 16 18 20 29 31	A	0 1 6 7 8 9 10 12 13 14 21 22
B	0 1 2 3 5 10 11 12 15 16 18 20 29 31	C	0 1 2 3 4 5 8 9 11 12 16 21
D	2 3 4 6 8 9 11 16 17 26 29	C	0 1 2 3 4 5 8 9 11 12 16 21
D	2 3 4 6 8 9 11 16 17 26 29	E	4 5 7 10 14 19 21 23 24 26 27 31
F	12 14 25 31	E	4 5 7 10 14 19 21 23 24 26 27 31
F	12 14 25 31	G	13 20 22 25 30
H	13 15 17 20 21 28	G	13 20 22 25 30
H	13 15 17 20 21 28	I	14 19 20 22 24 25
J	15 17 19 27 30	I	14 19 20 22 24 25
J	15 17 19 27 30	K	15 16 18 19 23 26 27 28 30
L	18 22 24 25 27 28 29 30	K	15 16 18 19 23 26 27 28 30

Table 7

In other embodiment of the present invention, also can obtain table 7 in the following way: behind the differentiation result that 128 scramblers are distinguished shown in the acquisition table 3, adopt A～L to identify scrambler respectively and distinguish respectively organizing among the result, obtain the group result shown in the table 5, according to the group result after the identifying shown in the table 5, and with reference to the corresponding relation between scrambler and the downlink frequency pilot code in the system specifications of TD-SCDMA shown in the table 1, determine each scrambler that obtains identifying respectively pairing downlink frequency pilot code of dividing into groups, thereby obtain the new group result shown in the table 7 with A～L.

Then, step 202 of the present invention among Fig. 2 is elaborated.

Step 202 of the present invention is: utilize genetic algorithm to search out the compound code word combination of each sub-district based on the optimum of basic scrambler according to work code channel number of setting and optional code channel scope.

Below illustrate earlier and why will search out the compound code word combination of each sub-district based on the optimum of basic scrambler.

Phase mutual interference between the compound code word that is made of basic scrambler changes with code word combination and different.Two row in the table 5 are got the compound key sub-block of a basic scrambler and spreading code respectively and carried out cross-correlation calculation, two kinds of forms of expression of the correlation between the compound key sub-block that can obtain being composited: shown in table 8 table 9 by TD-SCDMA system base scrambler and spreading code.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	1	0	8	0	0	0	0	8	0	8	0	0	0	0	0	0	8
2	8	0	0	0	0	0	0	8	0	8	0	0	0	0	8	0	1	0	8	0	0	0	0	8	0	8	0	0	0	0	0	0	8
2	8	0	0	0	0	0	0	8	0	8	0	0	0	0	8	0	3	0	0	0	8	8	0	0	0	0	0	8	0	0	8	0	0
4	0	0	8	0	0	8	0	0	0	0	0	8	8	0	0	0	3	0	0	0	8	8	0	0	0	0	0	8	0	0	8	0	0
4	0	0	8	0	0	8	0	0	0	0	0	8	8	0	0	0	5	0	0	8	0	0	8	0	0	0	0	0	8	8	0	0	0
6	0	0	0	8	8	0	0	0	0	0	8	0	0	8	0	0	5	0	0	8	0	0	8	0	0	0	0	0	8	8	0	0	0
6	0	0	0	8	8	0	0	0	0	0	8	0	0	8	0	0	7	8	0	0	0	0	0	0	8	0	8	0	0	0	0	8	0
8	0	8	0	0	0	0	8	0	8	0	0	0	0	0	0	8	7	8	0	0	0	0	0	0	8	0	8	0	0	0	0	8	0
8	0	8	0	0	0	0	8	0	8	0	0	0	0	0	0	8	9	8	0	0	0	0	0	0	8	0	8	0	0	0	0	8	0
10	0	8	0	0	0	0	8	0	8	0	0	0	0	0	0	8	9	8	0	0	0	0	0	0	8	0	8	0	0	0	0	8	0
10	0	8	0	0	0	0	8	0	8	0	0	0	0	0	0	8	11	0	0	8	0	0	8	0	0	0	0	0	8	8	0	0	0
12	0	0	0	8	8	0	0	0	0	0	8	0	0	8	0	0	11	0	0	8	0	0	8	0	0	0	0	0	8	8	0	0	0
12	0	0	0	8	8	0	0	0	0	0	8	0	0	8	0	0	13	0	0	0	8	8	0	0	0	0	0	8	0	0	8	0	0
14	0	0	8	0	0	8	0	0	0	0	0	8	8	0	0	0	13	0	0	0	8	8	0	0	0	0	0	8	0	0	8	0	0
14	0	0	8	0	0	8	0	0	0	0	0	8	8	0	0	0	15	0	8	0	0	0	0	8	0	8	0	0	0	0	0	0	8
16	8	0	0	0	0	0	0	8	0	8	0	0	0	0	8	0	15	0	8	0	0	0	0	8	0	8	0	0	0	0	0	0	8

Table 8

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	1	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
2	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	1	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
2	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	3	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	3	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	5	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
6	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	5	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4

7	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
7	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	8	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
9	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	8	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
9	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	10	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
11	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	10	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
11	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	12	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
13	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	12	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
13	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	14	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
15	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	14	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
15	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	16	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4

Table 9

Investigation table 8 and table 9 can find, the correlation mould value between the compound code word that is made of basic scrambler is 8,4 or 0.Correlation mould value is big more, and the phase mutual interference between corresponding code word is big more.

For example, to 3 cell reuse networks shown in Figure 5, the equal 8 code channel work in every sub-district, and suppose that the power that each code channel of adjacent sub-district arrives this sub-district receiving terminal equates the code word suitable to this network allocation.

Ignore the effect of phase mutual interference between the different composite code word if only investigate the planning of scrambler, choose cell configuration scheme 1:

Sub-district 1: basic scrambler A, the

work code channel

1,2,3,4,5,6,7,8}

Sub-district 2: basic scrambler K, the

work code channel

1,2,3,4,5,6,7,8}

Sub-district 3: basic scrambler L, the

work code channel

1,2,3,4,5,6,7,8}

Dispose the spreading code that three cell operation code channels use, can obtain table 10, table 11, the work code channel bears adjacent area interference form:

1	0 0 0 0 0 0 0 0
1	0 0 0 0 0 0 0 0	2	0 0 0 0 0 0 0 0
3	0 0 0 0 0 0 0 0	2	0 0 0 0 0 0 0 0

Table 10

Table 10 first is classified cell id as, and second classifies the every work code channel to each sub-district as, and relevant mould value with it is 8 adjacent sub-district code channel quantity.

1	16 16 16 16 16 16 16 16
1	16 16 16 16 16 16 16 16	2	16 16 16 16 16 16 16 16
3	16 16 16 16 16 16 16 16	2	16 16 16 16 16 16 16 16

Table 11

Table 11 first is classified cell id as, and second classifies the every work code channel to each sub-district as, and relevant mould value with it is 4 adjacent sub-district code channel quantity.

In fact, above-mentioned network configuration is not the optimal network allocation plan, chooses following network configuration 2:

Sub-district 1---basic scrambler C, work code

channel spreading code

1,2,3,4,5,6,7,8};

Sub-district 2---basic scrambler H, work code

channel spreading code

1,3,5,7,9,11,13,15};

Sub-district 3---basic scrambler I, work code

channel spreading code

1,3,5,7,9,11,13,15};

Can obtain table 12, table 13, the work code channel bears adjacent area interference form:

Table 12

Table 12 first is classified cell id as, and second classifies the every work code channel to each sub-district as, and relevant mould value with it is 8 adjacent sub-district code channel quantity.

1	16 16 16 16 16 16 16 16
1	16 16 16 16 16 16 16 16	2	8 8 8 8 8 8 8 8
3	8 8 8 8 8 8 8 8	2	8 8 8 8 8 8 8 8

Table 13

Table 13 first is classified cell id as, and second classifies the every work code channel to each sub-district as, and relevant mould value with it is 4 adjacent sub-district code channel quantity.

Contrasted as seen by table 10, table 11 and table 12, table 13, in the network code word allocation plan 2, the relevant mould value with it of every work code channel of sub-district 2 and sub-district 3 is that 4 adjacent sub-district code channel quantity is lacked than scheme 1, and total interference of bearing is little than scheme 1.Obviously, allocation plan 2 is better than allocation plan 1, and allocation plan 2 can reduce the interference from adjacent sub-district, effectively promotes link performance and power system capacity.The present invention proposes to search out the compound code word combination of each sub-district based on the optimum of basic scrambler when the network planning, according to the compound code word combination of the optimum that searches, determines the spreading code that use the sub-district when moving in system.

Step 202 of the present invention has been used the method for the compound code word combination of search provided by the invention among Fig. 2, and the grouping of scrambler and downlink frequency pilot code is realized as constraints.

The basic step of genetic algorithm comprises:

A, initial population generate;

B, each individuality in the colony is carried out fitness assessment;

C, selection participate in the individuality of heredity;

D, individuality intersect to form new individuality;

E, new individual variation generate colony of future generation;

F, judge whether genetic iteration stops, if then finish; Otherwise return execution in step B, each individuality in the colony of new generation is carried out the fitness assessment.

The method that the present invention searches for compound key is provided with gene earlier: based on the compound code word of every work code channel, adopt the feature of identical scrambler in conjunction with the every sub-district of TD-SCDMA system, propose at the biradical of sub-district because of scheme: the basic scrambler that use all sub-districts constitutes the monobasic gene and is called basic scrambler gene; The spreading code that use the sub-district constitutes the monobasic gene and is called the spreading code gene, and the combination of basic scrambler gene and spreading code gene constitutes the genes of individuals of yard programme jointly, forms the binary gene structure.

The gene code design:

Base scrambler gene adopts the array sequence characterization, and each element sequence number of array is represented the sub-district sequence number, and element value is represented the employed basic scrambler of respective cell.The spreading code gene adopts binary matrix to characterize, and the matrix line number is total number of cells, and the row sequence number is corresponding with the sub-district sequence number.Every row is stored 16 binary values, represents the behaviour in service of 16 spread spectrum code channels.Binary numeral is 0, is illustrated in the spreading code that does not use corresponding sequence number in the respective cell; Binary numeral is 1, represents that corresponding spread spectrum code channel is used.

For example, the basic scrambler gene and the spreading code gene representation of the network configuration 2 employed scramblers of network configuration shown in Figure 5 and spreading code are as follows:

Base scrambler gene: { C, H, I}

The spreading code gene:

[\begin{matrix} 1 & 1 & 1 & 1 & 1 & 1 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ 1 & 0 & 1 & 0 & 1 & 0 & 1 & 0 & 1 & 0 & 1 & 0 & 1 & 0 & 1 & 0 \\ 1 & 0 & 1 & 0 & 1 & 0 & 1 & 0 & 1 & 0 & 1 & 0 & 1 & 0 & 1 & 0 \end{matrix}]

This a kind of configuration is exactly the body one by one of the genetic algorithm of the present invention's use.

Referring to Fig. 6, the flow chart of a preferred embodiment of Fig. 6 compound code word combined method for the present invention searches for.This flow process may further comprise the steps:

Step 601, generating unit is divided the configuration assembled scheme at random, with biradical because of form characterize, as the individuality of initial population.Wherein, spreading code will dispose according to the work code channel number and the optional code channel scope of each cell setting in the step 201.This step is the step that generates of the initial population in the genetic algorithm just.

Step 602 is assessed every kind of allocation plan of network base scrambler and spreading code in the colony, and this step is exactly the step that each individuality in the initial population in the genetic algorithm carries out the fitness assessment.

The ideal adaptation degree assessed comprises two processes:

1, calculates each individual penalty value.Realize that by a penalty penalty is based on the work interference size design that code channel bore, the interference of bearing is big, and corresponding penalty value is big.Calculate the penalty value that obtains and comprise following four parts: wherein most important is a, b, three parts of c.

(a) total stack of the interference that all code channels bore, the first of formation penalty value.For example, to the interference form of two kinds of configuring conditions shown in Figure 6, arrive under the condition that the power of this sub-district receiving terminal equates at supposition adjacent sub-district each code channel: table 11 and table 13 just show the interference that three each code channels of sub-district are born.

(b) code channel that exceeds interference threshold is appended punishment, constitute the second portion of penalty value;

(c) set the code channel quantity thresholding that bears large disturbance that each sub-district allows appearance, punishment is appended in the sub-district that exceeds this thresholding in the individuality, constitute the third part of penalty value;

(d) calculate each code channel and bear standard deviation or the variance of disturbing size, in view of the above individuality is appended punishment, individual corresponding the appending that variance is big punished greatly the 4th part of formation penalty value.

2, calculate each ideal adaptation degree: the present invention carries out the ideal adaptation degree by following formula and calculates.

fitness＝Penalty_Max-Penalty_indi+C

In the formula, fitness is the fitness of single individuality; Penalty_indi is the penalty value of single individuality; Penalty_Max is an individual penalty value maximum in the generation colony; C is a constant, and the selection of C value should be satisfied all individualities and all have the selected condition that participates in the probability of heredity.As seen, individual penalty value is big more, and individual fitness is low more.

For guaranteeing that some good gene models because individual weak fitness was not eliminated too early in the starting stage, can consider initial several generations colony ideal adaptation degree is done some conversion,, make ideal adaptation degree difference reduce as evolution etc.

For guaranteeing to have convergence preferably in loop iteration ending phase colony, can consider the ideal adaptation degree of last several generations colony is done certain conversion, as square etc., increase the difference of ideal adaptation degree.

Step 603 selects to participate in hereditary individuality.This step is based on the individuality that the ideal adaptation degree selects to participate in heredity, and basic skills comprises following three processes:

1, calculate the summation of all ideal adaptation degree in the colony: fitness_total=∑ fitness_i, wherein fitness_i represents i individual fitness;

2, calculate each individual selecteed probability in the colony

Probability P _ i=fitness_i/fitness_total

Wherein P_i represents i individual selected probability;

3, select the individual genetic manipulation that participates in according to the selected probability of individuality.

Step 604 is carried out individual in twos the intersection to the basic scrambler gene of selecting to participate in hereditary individuality, generates new individuality.This step can adopt certain crossover algorithm after selecting two individualities, and for example: single-point, 2 or multiple spot intersect the intersection of finishing basic scrambler gene.The new individuality that is produced is judged whether violate predefined constraints, for example, according to grouping of the present invention, identical constraintss such as basic scrambler can not be used in adjacent two sub-districts.If violation constraints redistributes basic scrambler and selection spreading code then for this sub-district.

Step 605 makes a variation to new individuality, generates colony of future generation.The mutation operation operand is the spreading code gene, and basic skills is as follows:

To bear the code channel of maximum interference in certain probability P selection individuality, this code channel is implemented mutation operation; Perhaps finish the code channel variation with other code channels in the probability 1-P selection individuality.Mutation process is presented as does the binary value negate with corresponding spreading code gene in the coding: select a new spread spectrum code channel to substitute chosen former spread spectrum code channel in the sub-district, the gene position of two spread spectrum code channel correspondences is done the binary system negate.

Step 606 judges whether genetic iteration stops, if then finish; Otherwise each individuality that returns in the step 602 pair colony of new generation carries out the fitness assessment.When using, can adopt multiple mode to finish genetic iteration.For example: the termination number of times of predetermined genetic iteration, every iteration is once counted once, when reaching the termination number of times, finishes automatically.Perhaps, order or hot key that a control iteration stops are set, after receiving that this order or this hot key are pressed, stop genetic iteration.

After genetic algorithm finished, all individual possibilities of the generation colony of acquisition were identical, the configuration combination of basic in other words scrambler of the compound code word combination of the optimum that this individuality promptly searches and spreading code.If the final generation colony that obtains is individual different, then need the user further therefrom to select the compound code word combination of an optimum.

In the present embodiment, the present invention in advance to the grouping of scrambler and downlink frequency pilot code only as constraints, can obtain disturbing minimum sub-district base scrambler and spreading code to distribute the result.Certainly, the method for the compound code word combination of search provided by the invention is not only applicable to this constraints, for other packet modes, only needs will divide into groups accordingly can realize as constraints yet.

Then, step 203 of the present invention among Fig. 2 is elaborated.

Step 203 of the present invention is: according to the corresponding relation of basic scrambler and downlink frequency pilot code, determine the downlink frequency pilot code that use each sub-district.Basic scrambler according to use the sub-district again according to table 7, distributes the employed downlink frequency pilot code in each sub-district (DwPTS).Can adopt different ways to distribute DwPTS, basic skills is as follows:

1, to arbitrary sub-district, the DwPTS that is distributed must belong to the DwPTS set of the pairing row of its basic scrambler, for example establishes the basic scrambler that uses the sub-district and is F, and then its DwPTS can only be { 12 1425 31};

2, neighbor cell can not use identical DwPTS arbitrarily.

Then, step 204 of the present invention among Fig. 2 is elaborated.

Step 204 of the present invention is: the relation of each scrambler in the basic scrambler of determining according to step 202, the downlink frequency pilot code that step 203 is determined and the TD-SCDMA system, determine the scrambler that use the sub-district.According to table 6 and table 1,, determine the employed scrambler in sub-district by DwPTS and the basic scrambler that use the sub-district.As establish the basic scrambler that uses the sub-district and be F, DwPTS is 12, with reference to table 1 as can be known the scrambler that uses of sub-district be scrambler 47;

At last, step 205 of the present invention among Fig. 2 is elaborated.

Step 205 of the present invention is: the scrambler that basic scrambler that the spreading code of the compound code word correspondence of the basic scrambler of the optimum that searches out according to step 202, step 202 are determined and step 204 are determined, determine the spreading code corresponding that use the sub-district with scrambler.Just the one-to-one relationship between the compound code word that is constituted according to compound code word that basic scrambler constituted and scrambler is determined the employed spreading code in each sub-district.Basic skills is as follows:

(1) the correlation mould value between the compound key sub-block of the compound key sub-block of the basic scrambler formation of calculation plot use and the scrambler formation that step 204 is determined, the form of expression that obtains correlation mould value form is similar to table 2;

(2) spreading code of the basic scrambler correspondence of being used by the sub-district obtains the spread spectrum code word of the scrambler correspondence used the sub-district, the spread spectrum code word equivalence that this spread spectrum code word is corresponding with basic scrambler.Distribute result, the spread spectrum code word of basic as can be known scrambler correspondence from final sub-district base scrambler and the spreading code that obtains of step 202.Finding step (1) correlation form is treated certain the compound code word i that investigates scrambler, if the relevant mould value with it of a compound code word j of basic scrambler is 16, has equivalence relation between then compound code word i and the compound code word j.

The present invention can also store repeatedly searching out the compound code word combination of each sub-district based on the multiple optimum of this grouping when the network planning, for example can store in the database of radio network controller (RNC).When moving, system can according to the scrambler that use this sub-district, determine the spreading code of sub-district code channel according to the compound code word combination of these optimums.Like this, just simplified the process of system's run duration dynamic assignment spreading code.Be example with the DCA algorithm still, referring to Fig. 7, Fig. 7 is after using district code word planing method of the present invention, the schematic flow sheet of DCA algorithm.This flow process comprises following two steps:

Step 701 is born bigger interference when causing link performance to descend, the compound code word combination of the optimum of storing in the database according to RNC, select target code channel when detecting some code channel.

Step 702 is carried out channel adjustment.

Compare with the flow process of prior art DCA algorithm shown in Figure 1, this flow process do not need the disturbed condition of the several code channels that may select for use in the same sub-district is predicted and estimated, according to estimated result the disturbed condition of several code channels carried out priority queueing again.Only need carry out data base querying simply just can select the target code channel, has obviously reduced the complexity that realizes, can save system resource.

By the above embodiments as seen, the district code word planing method of this TD-SCDMA of the present invention system, the mutual strong jamming of neighbor cell work code channel that may occur in the time of can avoiding the networking of TD-SCDMA system same frequency is disturbed in the reduction system.The method of the compound code word combination of TD-SCDMA systematic search of the present invention can search out the optimum compound code word combination of each cell operation code channel when the network planning, and the system that can be reduced in moves the complexity of spreading code dynamic assignment therebetween.

Claims

1. the district code word planing method of a time-division synchronous code division multiple access TD-SCDMA system, it is characterized in that, whether this method exists strong correlation to divide into groups the basis of the scrambler in the TD-SCDMA system in advance each other, obtain the basic scrambler and the corresponding descending pilot frequency code character thereof of TD-SCDMA system, wherein, described basic scrambler is the scrambler in same scrambler grouping; In TD-SCDMA system network planning process, finish the distribution of sub-district base scrambler and spread spectrum code word, downlink frequency pilot code, and and then finish the distribution of cell scrambling and spread spectrum code word, its assigning process may further comprise the steps:

4) according to step 2) the pairing basic scrambler of compound code word combination of the basic scrambler of each sub-district optimum of searching out and the downlink frequency pilot code that step 3) is determined respectively with the TD-SCDMA system in the relation of each scrambler, determine the scrambler that use each sub-district;

2. the method for claim 1 is characterized in that, the process that this method obtains the descending pilot frequency code character of basic scrambler and correspondence thereof in advance may further comprise the steps:

3. method according to claim 2 is characterized in that, described step C comprises:

Step C2: by determined scrambler base downlink frequency pilot code is divided into groups again, divide the result, with the corresponding corresponding one group of downlink frequency pilot code of each basic scrambler of each scrambler grouping thereby obtain new code word.

4. method according to claim 3 is characterized in that step C1 comprises:

5. method according to claim 4 is characterized in that, among the step C12, scrambler of described selection comprises as basic scrambler:

Step C121: from a code character that is different from the code character of having selected, select a scrambler;

Step C123: with selected scrambler as described basic scrambler.

6. method according to claim 5, it is characterized in that, in step C12, if in this second group, can't find with step C11 in selected this scrambler belong to the scrambler of the different scrambler code character in the grouping scheme of TD-SCDMA system specifications respectively, then this method further comprises:

7. method according to claim 3 is characterized in that step C2 comprises:

8. method according to claim 2 is characterized in that step C comprises:

9. the method for claim 1 is characterized in that, the method for the work code channel number of each sub-district of the described setting of step 1) and optional code channel scope is: the work code channel number of setting each sub-district by traffic forecast; Then, according to the 3GPP criterion that selection is used about code channel, determine optional code channel scope.

10. the method for claim 1 is characterized in that, described step 2) may further comprise the steps:

11. method as claimed in claim 10 is characterized in that, described step 21) comprise that further the gene code method is:

12. method as claimed in claim 10 is characterized in that, described step 22) may further comprise the steps:

211) calculate individual penalty value;

212) calculate the ideal adaptation degree with following formula:

fitness＝Penalty_Max-Penalty_indi+C

13. method as claimed in claim 12 is characterized in that, described penalty value also comprises:

14. method as claimed in claim 12 is characterized in that, described step 212) further comprise:

15. method as claimed in claim 10 is characterized in that step 23) the described selection method that participates in the individuality of heredity may further comprise the steps:

Wherein fitness_i represents i individual fitness;

232) calculate each individual selecteed probability in the colony

Probability P _ i=fitness_i/fitness_total,

Wherein P_i represents i individual selected probability;

16. method as claimed in claim 10 is characterized in that step 24) described individual method of intersecting is: adopt single-point, or multiple spot to intersect the intersection of finishing basic scrambler gene at 2.

17. method as claimed in claim 10, it is characterized in that, described step 24) further comprises: judge whether the new individuality that is produced violates predefined constraints,, redistribute basic scrambler and selection spreading code then for this sub-district if violate constraints.

18. method as claimed in claim 10 is characterized in that step 25) method of described individual variation is:

19. method as claimed in claim 18 is characterized in that step 25) described mutation process does the binary value negate for the spreading code gene in the individuality that described selection is participated in heredity.

20. method as claimed in claim 10 is characterized in that, described step 26) be: the termination number of times of predetermined genetic iteration, if the number of times of genetic iteration reaches the termination number of times then stops genetic iteration, otherwise return execution in step 22);

Perhaps, order or hot key that the control iteration stops are set, this termination is ordered or hot key is pressed if received, and then stops genetic iteration; Otherwise return execution in step 22).

21. the method for claim 1 is characterized in that, step 3) is described determines that the method for the downlink frequency pilot code that use each sub-district is:

22. the method for claim 1 is characterized in that, the method for the spreading code that use the described definite sub-district of step 5) may further comprise the steps:

23. the method for a TD-SCDMA systematic search compound key combination is characterized in that this method may further comprise the steps:

24. method as claimed in claim 23 is characterized in that, described step 1) comprises that further the gene code method is:

25. method as claimed in claim 23 is characterized in that, described step 2) may further comprise the steps:

21) calculate individual penalty value;

22) calculate the ideal adaptation degree with following formula:

fitness＝Penalty_Max-Penalty_indi+C

26. method as claimed in claim 25 is characterized in that, described penalty value also comprises:

27. method as claimed in claim 25 is characterized in that, described step 22) further comprise:

28. method as claimed in claim 25 is characterized in that, the method that the described selection of step 3) participates in the individuality of heredity may further comprise the steps:

Wherein fitness_i represents i individual fitness;

32) calculate each individual selecteed probability in the colony

Probability P _ i=fitness_i/fitness_total,

Wherein P_i represents i individual selected probability;

29. method as claimed in claim 23 is characterized in that, the described individual method of intersecting of step 4) is: adopt single-point, or multiple spot to intersect the intersection of finishing basic scrambler gene at 2.

30. method as claimed in claim 23, it is characterized in that, described step 4) further comprises: judge whether the new individuality that is produced violates predefined constraints, if violate constraints, redistribute basic scrambler and selection spreading code then for this sub-district.

31. method as claimed in claim 23 is characterized in that, the method for the described individual variation of step 5) is:

32. method as claimed in claim 23 is characterized in that, the described mutation process of step 5) is done the binary value negate for the spreading code gene in the individuality that described selection is participated in heredity.

33. method as claimed in claim 23 is characterized in that, described step 6) is: the termination number of times of predetermined genetic iteration, if the number of times of genetic iteration reaches the termination number of times then stops genetic iteration, otherwise return execution in step 2);