Background technology
The introducing of code division multiple access (CDMA, Code Division Multiple Access) technology, for mobile communication system provides a new resource, namely the code resource.At TD SDMA (TD-SCDMA, Time Division-Synchronous Code Division Multiple Access) in system, can utilize scrambler to carry out the scrambling processing to the data in channel, down direction, utilize scrambler to distinguish different residential quarters, up direction, base station (NodeB) utilizes scrambler to distinguish the user from different districts.
When carrying out the network planning, for fear of presence of intercell interference, improve network performance, need to carry out effectively also rational planning code resources, especially in the TD-SCDMA system, 128 scramblers only be arranged, the code resource is considerably less, therefore, more needs these scramblers are carried out effectively and reasonably planning.
At present, mainly utilize the correlation of compound key (scrambler multiply by spreading code) to plan scrambler, be about to 128 scramblers and be divided into 12 groups.Specifically, each scrambler is multiplied each other with each spreading code respectively, obtains a series of compound key, according to formula (1), calculate the correlation between every two compound keys:
Wherein, i and j representative be two compound keys arbitrarily, and N is code length.
According to result of calculation, 128 scramblers are divided into to 12 groups, i.e. 12 scrambler collection (SCS, Scrambling Code Set), group forming criterion is: any two scramblers in same grouping may occur that all compound key overlaps the situation of (correlation that is compound key is not 0), and the situation that all not there will be compound key to overlap of any two scramblers between on the same group not.
In the manner described above, can obtain following 12 scrambler collection:
SCS1:0 (being scrambler 0), 4,25,26,28,29,33,39,41,42,48,52,54,56,84,89 (16);
SCS2:1,5,7,10,15,20,40,46,47,49,61,64,75,82,118,126 (16);
SCS3:2,3,6,11,12,17,22,23,34,35,36,38,45,50,65,86 (16);
SCS4:8,9,13,14,18,19,24,27,32,37,44,67,70,104,116,117 (16);
SCS5:16,21,30,31,43,59,78,85,92,94,99,105,107,109,124,125 (16);
SCS6:63,66,72,79,93,95,106,110,113,123 (10);
SCS7:73,74,90,98,103,111,114,119,121 (9);
SCS8:55,60,71,83,87,112,115 (7);
SCS9:57,77,81,88,96,97,101 (7);
SCS10:62,68,69,76,108,122 (6);
SCS11:53,80,91,100,120 (5);
SCS 12:51,58,102,127 (4).
When being each cell allocation scrambler, usually, be positioned at the concentrated scrambler of same scrambler and can not distribute to adjacent residential quarter, this is stronger because be positioned at the concentrated scrambler correlation of same scrambler, orthogonality is poor.
Adopt this method of salary distribution to reduce to a certain extent presence of intercell interference, still, also can there be certain problem in this method of salary distribution in actual applications, such as:
Too coarse: the above-mentioned method of salary distribution has been considered just that adjacent residential quarter can not be divided and has been coordinated in the scrambler that same scrambler is concentrated, for some situation, such as, residential quarter A and residential quarter B be the other side's neighbor cell each other, for after residential quarter A distributed a scrambler in scrambler collection 1, in principle, can distribute to residential quarter B from optional scrambler scrambler collection 2~12, but, select different scramblers to bring different impacts to the interference of two minizones, it is optimum namely may having one, but the existing method of salary distribution is not considered this problem;
in addition, do not consider the problem of residential quarter, cobasis station: usually, meeting three residential quarters of subordinate, a base station, be assumed to be residential quarter D, residential quarter E and residential quarter F, residential quarter D so, residential quarter E and residential quarter F will be the residential quarter at cobasis station, correspondingly, residential quarter E and residential quarter F are the residential quarter, cobasis station of residential quarter D, in prior art, usually residential quarter, cobasis station can not processed as neighbor cell, so, if be that residential quarter D and residential quarter E distribute scrambler, just will can not follow and be positioned at the scrambler that same scrambler concentrates and can not distribute to the principle of adjacent residential quarter, like this, residential quarter D and residential quarter E just may be assigned to and be positioned at the scrambler that same scrambler is concentrated, thereby cause existing larger interference.
Embodiment
For problems of the prior art, a kind of scrambler double priority level distribution method that can reduce presence of intercell interference is proposed in the present invention.
For make technical scheme of the present invention clearer, understand, referring to the accompanying drawing embodiment that develops simultaneously, scheme of the present invention is described in further detail.
Fig. 1 is the flow chart of scrambling code distribution method embodiment of the present invention.As shown in Figure 1, comprise the following steps:
Step 11: determine the residential quarter of scrambler to be allocated, and by the residential quarter of each scrambler to be allocated according to priority from high to low order sort; According to priority order from high to low, the residential quarter X (being designated hereinafter simply as residential quarter X) for each scrambler to be allocated, process according to mode shown in step 12~18 respectively.
In this step, at first determine to participate in the residential quarter of planning, namely which residential quarter need to be distributed scrambler, and how to confirm is prior art; Then, sorted according to priority order from high to low in the residential quarter of each scrambler to be allocated of determining, sortord can be:
1) calculate the priority value of the residential quarter of each scrambler to be allocated, priority value=neighbor cell number (all neighbor cells, be not limited only to the residential quarter of scrambler to be allocated)+scrambler number (the presumable scrambler that distributed in neighbor cell that neighbor cell has distributed, and the not distribution scrambler that has), larger according to priority value, the principle that priority is higher, carry out just minor sort by the residential quarter of each scrambler to be allocated;
2) judge in the residential quarter of each scrambler to be allocated whether have after first minor sort the residential quarter, cobasis station that is in primary residential quarter, if exist, before at the beginning of the sorting position of residential quarter, cobasis station being adjusted to, after minor sort, being in primary residential quarter, namely the priority of residential quarter, cobasis station is the highest; If the quantity of residential quarter, cobasis station is greater than 1, the sequencing of each residential quarter, cobasis station can arrange arbitrarily; In addition, if there is no residential quarter, cobasis station, without adjusting.
Step 12: find out the residential quarter, cobasis station and the neighbor cell that distribute scrambler of residential quarter X, determine the scrambler collection at the scrambler place that each has distributed; Simultaneously, according to distance, by the order as far as near, will distribute each residential quarter, cobasis station and the neighbor cell of scrambler to sort, and statistics have been distributed the residential quarter, cobasis station of scrambler and the number Y of neighbor cell.
In actual applications, the specific implementation of scheme of the present invention can be set flexibly according to actual needs, such as, if do not implement adjacent section planning, can't obtain so the neighbor cell of residential quarter X, therefore, can only for residential quarter, cobasis station, carry out subsequent treatment; In addition, even carried out adjacent section planning, also can when carrying out subsequent treatment, whether need to consider by the interface prompt user neighbor cell, if do not consider, only for residential quarter, cobasis station, carry out subsequent treatment, if necessary, simultaneously for residential quarter, cobasis station and neighbor cell, carry out subsequent treatment, suppose for residential quarter, cobasis station and neighbor cell, to carry out subsequent treatment simultaneously in the present embodiment.
In the present embodiment, at first according to existing mode, namely according to the correlation of compound key, 128 scramblers are divided into to 12 scrambler collection; Afterwards, for each scrambler collection X, determine that respectively its corresponding priority is 1 to N scrambler collection, N is the positive integer greater than 1, and the value of supposing N in the present embodiment is 3.
Determine that priority that each scrambler collection X is corresponding is that the mode of 1 to 3 scrambler collection is as follows: for each scrambler collection X, calculate respectively the correlation of itself and other 11 scrambler collection, such as, calculate the correlation of scrambler collection X and scrambler collection Y (other 11 scramblers concentrate one), can first calculate respectively so each scrambler in scrambler collection X and the correlation between each scrambler in scrambler collection Y, each correlation that then will calculate is averaged, and this average is the correlation between scrambler collection X and scrambler collection Y; Can calculate two correlations between scrambler according to mode shown in formula (1), in this case, i and j represent respectively two scramblers arbitrarily; Afterwards, the order ascending according to correlation sorts to described other 11 scrambler collection, to be defined as priority that scrambler collection X is corresponding be 1 scrambler collection by after sequence, being in 4 scrambler collection of first 4, it is 2 scrambler collection that 7 scrambler collection of remainder are defined as to priority that scrambler collection X is corresponding, and it is 3 scrambler collection that scrambler collection X self is defined as to priority that scrambler collection X is corresponding.
In the manner described above, can obtain priority that each scrambler set pair answers is that 1 scrambler collection is as follows respectively:
SCS1:{SCS6、SCS7、SCS10、SCS12};
SCS2:{SCS3、SCS6、SCS7、SCS8};
SCS3:{SCS2、SCS8、SCS9、SCS11};
SCS4:{SCS5、SCS8、SCS9、SCS11};
SCS5:{SCS4、SCS9、SCS10、SCS12};
SCS6:{SCS1、SCS2、SCS7、SCS10};
SCS7:{SCS1、SCS2、SCS6、SCS12};
SCS8:{SCS2、SCS3、SCS4、SCS11};
SCS9:{SCS3、SCS4、SCS5、SCS11};
SCS10:{SCS1、SCS5、SCS6、SCS12};
SCS11:{SCS3、SCS4、SCS8、SCS9};
SCS12:{SCS1、SCS5、SCS7、SCS10};
The priority that is scrambler collection 1 correspondence is that 1 scrambler integrates as scrambler collection 6,7,10 and 12, and other repeats no longer one by one.
Can obtain priority that each scrambler set pair answers and be 2 scrambler collection as follows respectively:
SCS1:{SCS2、SCS3、SSC4、SCS5、SCSS8、SCS9、SCS11};
SCS2:{SCS1、SCS4、SCS5、SCS9、SCS10、SCS11、SCS12};
SCS3:{SCS1、SCS3、SCS4、SCS5、SCS6、SCS7、SCS10、SCS12};
SCS4:{SCS1、SCS2、SCS3、SCS4、SCS6、SCS7、SCS10、SCS12};
SCS5:{SCS1、SCS2、SCS3、SCS5、SCS6、SCS7、SCS8、SCS11};
SCS6:{SCS3、SCS4、SCS5、SCS6、SCS8、SCS9、SCS11、SCS12};
SCS7:{SCS3、SCS4、SCS5、SCS7、SCS8、SCS9、SCS10、SCS11};
SCS8:{SCS1、SCS5、SCS6、SCS7、SCS8、SCS9、SCS10、SCS12};
SCS9:{SCS1、SCS2、SCS6、SCS7、SCS8、SCS9、SCS10、SCS12};
SCS10:{SCS2、SCS3、SCS4、SCS7、SCS8、SCS9、SCS10、SCS11};
SCS11:{SCS1、SCS2、SCS5、SCS6、SCS7、SCS10、SCS11、SCS12};
SCS12:{SCS2、SCS3、SCS4、SCS6、SCS8、SCS9、SCS11、SCS12}。
In this step, find out the residential quarter, cobasis station and the neighbor cell that distribute scrambler of residential quarter X, determine the scrambler collection at the scrambler place that each has distributed, and the number Z of the scrambler collection at each scrambler place of having distributed of statistics, simultaneously, according to distance, by the order as far as near, will distribute each residential quarter, cobasis station and the neighbor cell of scrambler to sort, and statistics have been distributed the residential quarter, cobasis station of scrambler and the number Y of neighbor cell.
The scrambler that distributes due to two different even more residential quarters may be positioned at same scrambler to be concentrated, and therefore, the value of Z will be less than or equal to Y.For instance, the residential quarter, cobasis station of distributing scrambler of residential quarter X and neighbor cell are residential quarter O, residential quarter P, residential quarter Q and residential quarter R, and wherein, the scrambler that residential quarter Q and residential quarter R distribute is positioned at same scrambler to be concentrated, therefore, the value of Z will be 3, and the value of Y will be 4.
Step 13: find out each self-corresponding priority of each scrambler collection of determining in step 12 and be 1 scrambler collection, form respectively the set of a scrambler collection, judge between each scrambler collection set whether have common factor, if exist, perform step 18, if there is no, perform step 14.
Owing to can not dividing and be coordinated in the scrambler that same scrambler is concentrated in the residential quarter at adjacent residential quarter and cobasis station, and priority is that the correlation of the scrambler collection that 1 scrambler collection is corresponding with it is minimum, therefore in this step, find out each self-corresponding priority of each scrambler collection of determining in step 12 and be 1 scrambler collection, form respectively the set of a scrambler collection, and judge between each scrambler collection set whether have common factor, and if exist, occuring simultaneously, each scrambler in occuring simultaneously all can be distributed to residential quarter X.
illustrate, in step 12, determine 3 scrambler collection, be respectively scrambler collection 1, scrambler collection 2 and scrambler collection 3, so, the scrambler collection that is 1 by the priority of scrambler collection 1 correspondence forms the set of a scrambler collection, the scrambler collection that is 1 by the priority of scrambler collection 2 correspondences forms the set of a scrambler collection, the scrambler collection that is 1 by the priority of scrambler collection 3 correspondences forms the set of a scrambler collection, judge between this 3 scrambler collection set and whether have common factor, namely judge { SCS6, SCS7, SCS10, SCS12}, { SCS3, SCS6, SCS7, SCS8} and { SCS2, SCS8, SCS9, between SCS11}, whether there is common factor, if exist, perform step 18, if there is no, perform step 14.
Step 14: two parameter i and j are set, and wherein, the initial value that the initial value of i is set to 1, j is set to 2, then performs step 15.
Step 15: be to be in after the scrambler collection of j joins this sequence in scrambler collection set corresponding to the residential quarter of i position by being according to distance priority that the scrambler set pair at the scrambler place of the residential quarter of i position distributing answers after being sorted by the order as far as near in step 12, and again judge between each scrambler collection set whether have common factor, if exist, perform step 18, if there is no, perform step 16.
illustrate, the residential quarter, cobasis station of distributing scrambler and the neighbor cell of residential quarter X are residential quarter O, residential quarter P, residential quarter Q and residential quarter R, wherein, apart from residential quarter X farthest, the scrambler at the scrambler place that residential quarter O distributes integrates as scrambler collection 1 residential quarter O, the scrambler at the scrambler place that residential quarter P distributes integrates as scrambler collection 2, the scrambler at the scrambler place that residential quarter Q and residential quarter R distribute integrates as scrambler collection 3, and the scrambler collection set that these 3 scrambler set pairs are answered is respectively { SCS6, SCS7, SCS10, SCS12}, { SCS3, SCS6, SCS7, SCS8} and { SCS2, SCS8, SCS9, SCS11}, between the set of 3 scrambler collection, without occuring simultaneously, therefore, the scrambler collection that is 2 by the priority of scrambler collection 1 correspondence joins { SCS6, SCS7, SCS10, in SCS12}, obtain { SCS6, SCS7, SCS10, SCS12, SCS2, SCS3, SSC4, SCS5, SCSS8, SCS9, SCS11}, and then judgement { SCS6, SCS7, SCS10, SCS12, SCS2, SCS3, SSC4, SCS5, SCSS8, SCS9, SCS11}, { SCS3, SCS6, SCS7, SCS8} and { SCS2, SCS8, SCS9, between SCS11}, whether there is common factor.
Step 16: whether the value that judges i equals Y, if so, performs step 17, otherwise, execution step 16 '.
Step 16 ': make i=i+1, then repeated execution of steps 15.
If the value of i is not equal to Y, make i=i+1, then perform step 15, namely for the residential quarter, cobasis station of distributing scrambler and X time, the neighbor cell middle distance residential quarter residential quarter far away of residential quarter X, the priority that the scrambler set pair at its scrambler place of distributing is answered is that 2 scrambler collection joins in its corresponding scrambler collection set, and again judges between each scrambler collection set whether have common factor.
Step 17: whether the value that judges j equals N, if not, perform step 17 ', if so, end process.
Step 17 ': make j=j+1, i=1, then repeated execution of steps 15.
If after for all of residential quarter X, having distributed the residential quarter, cobasis station of scrambler and neighbor cell all to process in the manner described above, being about to priority that the scrambler set pair at its scrambler place of distributing answers and being 2 scrambler collection joins in its corresponding scrambler collection set, still get less than common factor, according to the distance by the order as far as near, for each of residential quarter X, residential quarter, cobasis station and the neighbor cell of scrambler have been distributed, process shown in repeating step 15, just this moment, priority reduced to 3.
In fact, in step 17, the value of j equals in the situation of N, it is non-existent also getting less than the possibility of occuring simultaneously, because when the j value equals N, each scrambler collection set will form by all 12 scrambler collection, so in actual applications, can not occur described in step 17 " if " this branch.
Step 18: each scrambler in occuring simultaneously sorts according to being assigned with number of times order from less to more, after sorting, is in primary scrambler and distributes to residential quarter X, process ends.
Scrambler in common factor is the scrambler that can distribute to residential quarter X, because the scrambler number in occuring simultaneously may be greater than 1, in line with selecting optimum principle, further reduce presence of intercell interference, at first each scrambler in occuring simultaneously is sorted according to being assigned with number of times order from less to more, after then just sorting, be in primary scrambler and distribute to residential quarter X.
Visible, in scheme of the present invention, by double priority level distribution method, namely, in conjunction with the priority of each scrambler collection and the priority of each scrambler in common factor, select the scrambler of an optimum to distribute to residential quarter X, thereby effectively reduced presence of intercell interference; In addition, in scheme of the present invention, the priority of residential quarter, cobasis station is set to the highest, is preferably it and distributes scrambler, thereby avoided the residential quarter use at cobasis station to be positioned at the scrambler that identical scrambler is concentrated, and has further reduced interference.
In addition, in prior art, the problem that the number of considering the scrambler place scrambler collection that distributes when neighbor cell and residential quarter, cobasis station can cause during over 11, such as, currently need to be that residential quarter X distributes scrambler, there are 12 neighbor cells in residential quarter X, and the scrambler that each neighbor cell distributes all is positioned at different scramblers and concentrates, that is to say, 12 scramblers concentrate all existing scramblers to be assigned with, so, no matter for residential quarter X distributes the concentrated scrambler of which scrambler, the problem of the scrambler that the adjacent residential quarter same scrambler of use is concentrated can appear inevitably all.
For this reason, in scheme of the present invention, propose, after step 12 shown in Figure 1, further judge that whether the value of described Z is greater than 11, if not, perform step 13, if, will distribute to residential quarter X, then process ends according to after the concentrated sequence of the scrambler apart from being in the scrambler place of distributing primary residential quarter after being sorted by the order as far as near, being in primary scrambler; Described each scrambler of concentrating according to the scrambler apart from being in the scrambler place of distributing primary residential quarter after being sorted by the order as far as near sorts according to being assigned with number of times order from less to more.Chosen distance farthest, thereby reduce disturbs.
In addition; in prior art; need to utilize descending synchronous code to distinguish adjacent residential quarter; and descending synchronous code usually can corresponding 4 scramblers; like this; if the corresponding same descending synchronous code of two different scrambling codes of two adjacent cell allocation, will cause these two adjacent residential quarters to distinguish, and can increase interference.
For this reason, in scheme of the present invention, propose, after step 12 shown in Figure 1, further in the judgement residential quarter, cobasis station of having distributed scrambler and neighbor cell, whether there is the residential quarter of using identical descending synchronous code with residential quarter X, if exist, (which scrambler the scrambler that this descending synchronous code is corresponding is positioned at is concentrated the scrambler that this descending synchronous code is corresponding from the concentrated deletion of corresponding scrambler, just from which scrambler, concentrate and delete), then perform step 13, if there is no, directly perform step 13.
In addition, in actual applications, may cook up in advance some reserved scramblers, these reserved scramblers are current can not be used, and when the future network dilatation, leaves the residential quarter of dilatation for and uses, and these reserved scramblers can be presented on interface, are prompted to the user.
, in scheme of the present invention, propose for this reason, can after execution of step 12, first these reserved scramblers be concentrated to deletion from corresponding scrambler, and then perform step 13, certainly, if there is no reserved scrambler, can directly perform step 13.
So far, namely completed introduction embodiment illustrated in fig. 1.
Follow-up, can deposit the scrambler allocation result in database, and be shown to the user, how to be shown as prior art.As shown in Figure 2, the scrambler allocation result schematic diagram of Fig. 2 for adopting scrambling code distribution method of the present invention to obtain, demonstrated 30 residential quarters altogether in Fig. 2.In addition, also the form of scrambler allocation result shown in Figure 2 with form can be shown below:
Base station IDs |
The base station title |
Residential quarter ID |
Cell name |
Block number (scrambler collection number) |
Descending synchronous code ID | Scrambler ID | |
1 |
482 |
1 |
1444 |
3 |
2 |
10 |
1 |
482 |
2 |
1445 |
4 |
3 |
12 |
1 |
482 |
3 |
1446 |
14 |
13 |
55 |
4 |
695 |
4 |
2083 |
15 |
14 |
59 |
4 |
695 |
5 |
2084 |
31 |
30 |
122 |
4 |
695 |
6 |
2085 |
20 |
19 |
79 |
7 |
700 |
7 |
2098 |
1 |
0 |
0 |
7 |
700 |
8 |
2099 |
17 |
16 |
66 |
7 |
700 |
9 |
2100 |
19 |
18 |
73 |
10 |
702 |
10 |
2104 |
13 |
12 |
51 |
10 |
702 |
11 |
2105 |
11 |
10 |
43 |
10 |
702 |
12 |
2106 |
23 |
22 |
90 |
13 |
746 |
13 |
2236 |
9 |
8 |
33 |
13 |
746 |
14 |
2237 |
24 |
23 |
93 |
13 |
746 |
15 |
2238 |
29 |
28 |
114 |
16 |
787 |
16 |
2359 |
8 |
7 |
28 |
16 |
787 |
17 |
2360 |
18 |
17 |
68 |
16 |
787 |
18 |
2361 |
5 |
4 |
16 |
19 |
1158 |
19 |
3472 |
26 |
25 |
102 |
19 |
1158 |
20 |
3473 |
16 |
15 |
62 |
19 |
1158 |
21 |
3474 |
6 |
5 |
21 |
22 |
1162 |
22 |
3484 |
18 |
17 |
69 |
22 |
1162 |
23 |
3485 |
27 |
26 |
106 |
22 |
1162 |
24 |
3486 |
22 |
21 |
85 |
25 |
1230 |
25 |
3688 |
7 |
6 |
25 |
25 |
1230 |
26 |
3689 |
32 |
31 |
127 |
25 |
1230 |
27 |
3690 |
25 |
24 |
98 |
28 |
1254 |
28 |
3760 |
2 |
1 |
4 |
28 |
1254 |
29 |
3761 |
15 |
14 |
58 |
28 |
1254 |
30 |
3762 |
28 |
27 |
108 |
Table one scrambler allocation result
In a word, adopt technical scheme of the present invention, can effectively reduce presence of intercell interference.
The foregoing is only preferred embodiment of the present invention, in order to limit the present invention, within the spirit and principles in the present invention not all, any modification of making, be equal to replacement, improvement etc., within all should being included in the scope of protection of the invention.