WO2011106969A1

WO2011106969A1 - Method and device for allocating physical cell identification

Info

Publication number: WO2011106969A1
Application number: PCT/CN2010/076884
Authority: WO
Inventors: 马松
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-03-02
Filing date: 2010-09-14
Publication date: 2011-09-09
Also published as: CN102196442A

Abstract

A method and device for allocating a Physical Cell Identification (PCI) are disclosed in the present invention, and the method includes that: when and satisfy the congruence relations: N_IDN ^cell=N_IDNb ^cellmod6, a new PCI is reallocated to a new cell, wherein, N_IDN ^cell is a PCI value of the new cell, and N_IDNb ^cellis a PCI value of an adjacent cell which has the same frequency as the new cell. With the method and device of the present invention, the mutual interference of the cell reference signals between adjacent cells which have the same frequency can be obtained, and the interference can be overcome effectively, wherein, the mutual interference is caused by an inappropriate allocation of the cell PCI.

Description

Method and device for assigning physical cell ID

The present invention relates to the field of mobile communications, and in particular, to a physical cell identification (Physical Cell Identification, PCI) allocation technology. Background technique

In the Long Term Evolution (LTE) communication system, the cell reference signal is mainly used for channel estimation and correlation demodulation. In practical applications, the frequency domain location of the reference signal of the same-frequency neighboring cell is the same, which causes The reference signals between adjacent cells generate relatively serious mutual interference, resulting in inaccurate channel estimation results, thus affecting the stability of the entire system.

The frequency domain location of the cell reference signal is related to the physical cell ID, and the time domain relationship and the frequency domain relationship are:

^ = 6 m + (v + v _shift ) mod 6

l = j0, N _s ^D _y ^ _b - 3 ιΐρ e {0,1}

~ [l if p G {2,3}

m = 0,1, ..., 2 · N ° _B ^L - 1 where represents the frequency domain position of the reference signal, Z represents the time domain position of the reference signal, represents the downstream bandwidth, and W _S ^D represents a sub-frame The number of Orthogonal Frequency Division Multiplexing (OFDM) symbols in one slot, ^ = ^0 (16 represents the frequency shift of the reference signal.

As shown in Figure 1, the location of the cell reference signal is different according to the PCI. There are six types of time-frequency positions of the cell reference signal of the cyclic prefix (CP). According to the prior art, it will appear. Because of the difference in PCI, the frequency domain position of the reference signal is different, so there is a problem when the cell reference signals of adjacent co-frequency cells have the same position. The reference signals of the two cells may generate strong interference, which causes errors when the UEs at the edge of the two cells perform channel estimation. Summary of the invention

In view of the above, the technical problem to be solved by the present invention is to overcome the problem of mutual interference between adjacent intra-frequency cell reference signals caused by improper allocation of adjacent PCI values in the PCI allocation process.

In order to solve the above problem, an aspect of the present invention provides a method for allocating a PCI, including: when a new cell is established, it is determined whether the PCI value allocated by the newly-created cell is equal to or equal to the following congruence relationship with the PCI value w of the same-frequency neighboring cell. :

If not, the PCI allocation of the newly created cell is successful; otherwise, the new cell is newly allocated with the new PCI.

Further, when the new cell is in the same base station (eNB) as the same frequency neighboring cell, the method is specifically:

Checking the PCI of the same-frequency zone by checking the PCI of the same-frequency zone, and determining whether the PCI of the newly-created cell and the PCI of the same-frequency neighboring zone satisfy the congruence relationship W ^≡A ^^ mod ⁶ , when the congruence relationship is satisfied, The new cell gives the suggested PCI value.

Further, when the new cell is not in the same eNB as the same frequency neighboring cell, the method is specifically:

The source end eNB of the newly built cell notifies the peer eNB of the PCI of the newly built cell;

Determining, by the peer eNB, whether the PCI of the new cell and the PCI of the same-frequency neighboring cell of the opposite eNB satisfy a congruence relationship ^ Ι ^ π ^ πκ Ι ⁶ , if yes, indicating the source eNB by using a signaling message The PCI of the newly-created cell may cause interference with the peer-to-peer neighboring-area reference signal; otherwise, the signaling of the source-side eNB indicates that the PCI of the newly-created cell does not cause the same as the opposite end. The interference between the reference signals of the frequency neighboring area;

When the source eNB learns that the PCI of the newly-created cell causes interference between neighboring intra-frequency cell reference signals of other eNBs, it provides a recommended PCI value for the newly-created cell.

Further, the method for giving the suggested PCI value to the newly created cell is specifically:

A1. Add 1 to the original PCI value to obtain a new PCI value w, that is, A ' = N + 1 and A ≠ N m. D6 ;

A2: traversing the PCI of the same-frequency neighboring cell in the eNB of the newly-created cell, and checking whether the relationship with the newly obtained PCI value 'satisfies the congruence relationship. If yes, step A1 is performed. Otherwise, the newly obtained PCI value is used as a suggestion for the new cell. PCI value.

Further, before the recommended PCI value is given to the newly-created cell, the method further includes the step of notifying the OMC that the PCI of the newly-created cell causes a reference signal interference of the same-frequency neighboring cell.

Further, the source end eNB and the opposite end eNB perform signaling interaction on the PCI of the new cell through the X2 interface.

Based on the above method, the present invention further provides a PCI distribution apparatus, the apparatus comprising: a determination module, configured to determine whether a PCI value of a new cell w= and a PCI value of a co-frequency neighboring zone satisfy a congruence relationship W ≡ mod6 .

And a redistribution module, configured to re-allocate a new PCI to the newly created cell when the PCI value of the newly created cell satisfies the congruence relationship.

Further, when the new cell is not in the same eNB as the same-frequency neighboring cell, the device further includes:

a notification module, configured to notify a PCI of the new cell to an eNB of the opposite end;

The second judging module is configured to determine whether the PCI of the newly-created cell and the PCI of the same-frequency neighboring cell of the opposite eNB satisfy the congruence relationship ^≡ w ^{mod 6} ;

a response module, configured to send, to the redistribution module, a determination result of the second determining module, if When the congruence relationship is satisfied, the redistribution module indicates the new cell by using a signaling message.

The PCI may cause interference with the reference signal of the peer-to-peer neighboring cell; otherwise, the signaling of the new cell of the redistribution module is not caused by the signaling message to cause interference with the reference signal of the same-frequency neighboring cell in the peer end. ;

The redistribution module is further configured to re-allocate the new cell to the new cell when it learns that the PCI of the new cell causes interference between neighboring intra-frequency cell reference signals of other eNBs.

Further, the redistribution module includes:

An assignment module, configured to add 1 to the original PCI value to obtain a new PCI value w ', ie, == +1, and

a decision module, configured to: when the evaluation module outputs a new PCI value, traverse the PCI of the same-frequency neighboring cell in the eNB of the new cell, and check whether the congruence relationship is satisfied with the new PCI value, if satisfied, Then, the evaluation module is notified to perform, otherwise the new PCI value is output as the recommended PCI value of the newly created cell.

Further, the device further includes:

The prompting module is used to prompt the OMC to create a new cell PCI to cause interference in the neighboring reference information. By adopting the method and device used in the present invention, it is possible to effectively overcome mutual interference of cell reference signals in the same frequency neighboring area due to improper allocation of PCI. DRAWINGS

Figure 1 is a possible distribution diagram of the cell reference signal 6;

2 is a flowchart of processing of an intra-frequency neighboring cell in an eNB according to the present invention;

3 is a flowchart of processing in which the same frequency neighboring cell is not in the same eNB;

4 is a schematic structural view of a PCI distribution device according to the present invention;

FIG. 5 is a schematic structural view of another PCI distribution device according to the present invention. detailed description

The basic idea of the present invention is to determine whether the PCI of the newly built cell and the PCI of the same-frequency neighboring cell satisfy the congruence relationship ^ ^≡ ^ ∞ ₀ (1 ⁶ , if satisfied, it is proved that the frequency domain positions of the downlink cell reference signals of the two cells are the same, If the interference of the reference signals between the two cells is caused, the new PCI value is re-allocated to the cell, so that mutual interference of the cell reference signals due to improper allocation of the PCI can be prevented.

Figure 2 shows the processing of two co-frequency cells in the same eNB. As shown in Figure 2, the following steps are included:

Step 201: Establish a new cell in an eNB, and allocate a PCI to it, which may be automatically allocated or manually allocated.

Step 202: Determine whether there is a co-frequency neighboring cell in the same eNB. If yes, perform step 203; otherwise, end the process;

Step 203: Check the PCI of the same-frequency temporary area one by one through the neighbor relationship, and determine whether the PCI of the new cell and the PCI of the neighboring cell satisfy the congruence relationship.

Mod ⁶ , if it is satisfied, it is proved that the allocated PCI causes interference of the intra-frequency neighbor cell reference signal, and then step 204 is performed; otherwise, the process ends.

Step butterfly 204: The eNB prompts the Operation Maintainance Centre (OMC), and the allocation of the PCI causes interference of the reference signal of the same-frequency neighboring cell, and gives a suggested PCI value to the OMC.

Figure 3 shows the processing of two co-frequency cells not in the same eNB. As shown in Figure 3, the following steps are included:

Step 301: Establish an X2 interface between two eNBs.

Step 302: Create a new cell in an eNB (ie, the source eNB) and allocate a PCI to it. Step 303: The source eNB informs the peer eNB of the PCI of the newly established cell through the X2 port. Step 304: The peer eNB checks whether the PCI of the new cell in the source eNB causes the same frequency. Mutual interference of cell reference signals;

Specifically, it is determined whether the PCI of the new cell of the source eNB and the PCI of the neighboring cell of the opposite eNB satisfy the congruence relationship w ≡ L m . d ⁶ to determine whether it will cause mutual interference of the same-frequency cell reference signals. If it is satisfied, it will prove that the mutual-frequency cell reference signals interfere with each other, and then proceed to step 305; otherwise, step 307 is performed.

Step 305: The peer eNB informs the source eNB through the X2 interface signaling that the PCI may cause mutual interference of the same-frequency cell reference signals.

Step 306: The source eNB learns that the PCI may cause interference between adjacent reference signals of the same frequency cell, prompting the OMC: the allocation of the PCI may cause the reference signal of the same frequency neighboring area to be interfered, and the recommended PCI value is given. To the OMC, the process ends.

Step 307: The peer eNB informs the source eNB that the PCI does not cause mutual interference of the same-frequency cell reference signals through the X2 interface signaling, and the source eNB notifies the OMC that the allocation is successful.

Application example 1

The following is an application example, which is a combination of the above two situations:

Step E101: Create a new cell in an eNB and assign PCI to the new cell: Set to W, either manually or automatically.

Step E102: traversing the neighboring cell relationship of the newly-created cell, if there is an intra-frequency neighboring cell in the local eNB of the cell, performing step E103; if only cells in other eNBs are in the same-frequency neighboring cell, step E106 is performed; The eNB refers to an eNB where a new cell is located. Step E 103: traverse the PCI of all the same-frequency neighboring cells, and set the PCI of the same-frequency neighboring area to calculate whether the PCI value of the newly-created cell and the PCI value of the same-frequency neighboring area satisfy the congruence relationship, that is,

m. d ⁶ , if yes, step E104 is performed; if not, step E106 is performed; step E104: adding a new PCI value ^ ' on the basis of the original PCI value, specifically: calculating mod 6 _;

Step E105: traversing the PCI of the intra-frequency neighboring cell in the eNB to which the new cell belongs, and checking whether the relationship with the newly obtained 'satisfying congruence relationship is satisfied. If yes, step E104 is performed again; if not, the newly obtained W is newly created. The recommended _PCI value of the cell, and temporarily stored in the eNB, step E106;

Step E106: Determine whether the newly created cell has an intra-frequency neighboring cell in another eNB, and there is an X2 port between the two eNBs;

Specifically, it may be determined by the information about the X2 port saved by the eNB; if yes, step E107 is performed; otherwise, the process ends.

Step E107: If ^ ' is not empty, the PCI of the newly added cell is set to be, and the source _e NB brings the message of the cell addition to the opposite eNB through the X2 port configuration update (X2 CONFIGURATION UPDATE) signaling. Reading neighbor eNB W X2 CONFIGURATION UPDATE signaling is carried in cells, are calculated for all cells in the PCI _e NB: ^N ^;

Step E108: The peer eNB determines whether the PCI brought by the PCI and the source end of all cells in the eNB satisfies the congruence relationship ^i^ N^^ mod ⁶ ;

If the above congruence relationship is not satisfied, return to the source eNB X2 port configuration success signaling (X2)

CONFIGURATION AC ), indicating that the PCI transmitted from the source end of the source eNB does not cause interference with the adjacent co-frequency cell reference signal of the local end; if the above congruence relationship is satisfied, the X2 port configuration failure signaling is returned (X2 CONFIGURATION) FAILURE), the source eNB is informed by a specific error code, and the allocation of this PCI may cause interference between adjacent intra-frequency cell reference signals.

Step E109: After the source eNB receives the X2 CONFIGURATION ACK signaling, if there is a cached W li', the protocol between the OMC and the base station prompts the OMC, and the previously allocated PCI value W causes the adjacent co-frequency cell reference signal. Interference between and give the suggested _PCI value

^Ν ^'; If there is no cache, notify OMC, PCI allocation is successful;

After receiving the X2 CONFIGURATION FAILURE signaling, the source eNB learns about this PCI. If interference occurs between the same-frequency neighbor cell reference signals of other eNBs, let ^ = ^, go to step E104 to recalculate the PCI recommended value. Application example 2

Based on the same inventive concept, the embodiment of the present invention further provides a device for assigning a physical cell ID. Since the principle of solving the problem is similar to the method for assigning a physical cell ID, the implementation of the device can be implemented by referring to the method. It will not be repeated here.

4 is a schematic structural diagram of a PCI distribution device according to the present invention, the device includes:

The judging module is configured to determine whether the PCI value w of the newly built cell and the PCI value of the co-frequency neighboring area satisfy the congruence relationship W ^≡ W mod6 .

Preferably, the device further includes: a prompting module, configured to prompt the OMC to create a cell of the cell to cause interference of the reference information of the area.

FIG. 5 is a schematic structural diagram of a PCI allocating apparatus according to another embodiment of the present invention, where the new cell is not in the same eNB as the same-frequency neighboring cell, and the difference from FIG. 4 is that the device further includes:

The notification module is configured to notify the eNB of the new cell to the peer eNB, where the PCI may be a PCI value that is determined by the determining module to not satisfy the congruence relationship, or may be a recommended PCI given by the redistribution module. Value

The second determining module is located at the peer eNB, and is configured to determine whether the PCI of the new cell and the PCI of the same-frequency neighboring cell of the opposite eNB satisfy the congruence relationship W ^≡ W mod 6 .

a response module, configured to send, by the peer eNB, a determination result of the second determining module to the redistribution module, and if the congruence relationship is satisfied, indicate, by using a signaling message, the PCI of the newly added cell by the redistribution module It will cause interference with the reference signal of the same-frequency neighboring cell in the opposite end; otherwise The signaling message indicates that the PCI of the newly established cell of the redistribution module does not cause interference with the reference signal of the peer-to-peer neighboring cell;

Preferably, the redistribution module includes: an assignment module, configured to add 1 to the original PCI value to obtain a new PCI value, ie, i' = A + l , and N ≠ N ' mod6 ; When the evaluation module outputs a new PCI value ^ ', it traverses the PCI of the intra-frequency neighboring cell in the eNB of the newly-created cell, and checks whether the congruence relationship is satisfied with the new PCI value. If yes, the evaluation module is notified, and the process is notified. Go to the evaluation module to perform the accumulation operation again; otherwise, the new PCI value is output as the recommended PCI value of the new ^ area.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

Claim

A method for allocating a physical cell identifier (PCI), the method comprising: determining, when a new cell is established, whether a PCI value w allocated by a new cell is equal to a co-frequency neighboring cell

The PCI value satisfies the following congruence relationship:

The method according to claim 1, wherein when the new cell and the same-frequency neighboring cell are in the same base station (eNB), the method is specifically:

Checking the PCI of the same-frequency zone by checking the neighboring zone relationship, and determining whether the PCI of the new cell and the PCI of the same-frequency neighboring zone satisfy the congruence relationship W= ^≡ W _b mod ⁶ , when the congruence relationship is satisfied, The new cell gives the suggested PCI value.

The method according to claim 1, wherein when the new cell is not in the same eNB as the same-frequency neighboring cell, the method is specifically:

Determining, by the peer eNB, whether the PCI of the new cell and the PCI of the same-frequency neighboring cell of the opposite eNB satisfy a congruence relationship ^1^^^^ mod ⁶ , if yes, indicating the source eNB by using a signaling message The PCI of the newly-created cell may cause interference with the peer-to-peer neighboring-area reference signal; otherwise, the signaling of the source-side eNB may not cause the same-frequency neighboring cell reference with the peer end. Interference between signals;

The method according to claim 2 or 3, wherein the method for giving the suggested PCI value to the newly created cell is specifically: Al, add 1 to the original PCI value to obtain a new PCI value, ie N = ^ leg + ¹ , and » d6 ;

A2: traversing the PCI of the same-frequency neighboring cell in the eNB to which the new cell belongs, and checking whether the PCI value meets the congruence relationship with the newly obtained PCI value. If yes, perform step A1. Otherwise, the newly obtained PCI value is used as a suggestion for the new cell. PCI value.

5. A method according to claim 2 or 3, characterized in that

Before the proposed PCI value is given to the newly created cell, the method further includes the step of notifying the OMC that the PCI of the newly created cell causes interference of a reference signal in the same frequency neighboring cell.

The method according to claim 3, wherein the source end eNB and the opposite end eNB perform signaling interaction on the PCI of the new cell through an X2 interface.

7. A PCI distribution device, comprising:

The determining module is configured to determine whether the PCI value of the newly created cell w= and the PCI value of the same-frequency neighboring area satisfy the congruence relationship ^{W ≡ N} ^ ^mod6 ;

The device according to claim 7, wherein, when the new cell is not in the same eNB as the same-frequency neighboring cell, the device further includes:

The second determining module is configured to determine whether the PCI of the newly-created cell and the PCI of the same-frequency neighboring cell of the opposite eNB satisfy the congruence relationship ≡ N^ _h mod 6 .

a response module, configured to send, to the redistribution module, a determination result of the second determining module, if the congruence relationship is satisfied, indicating, by using a signaling message, that the PCI of the newly added cell in the redistribution module is caused by the peer end Interference between the same-frequency neighboring cell reference signal; otherwise, the signaling of the redistribution module indicates that the PCI of the newly-created cell does not cause a reference signal with the peer-to-peer neighboring cell reference signal. Interference

The apparatus according to claim 7, wherein the redistribution module comprises: an evaluation module, configured to add a new PCI value w ' by adding an original PCI value, ie

A = N +1, and N ≠A mod6 ; a decision module, configured to traverse the PCI of the intra-frequency neighboring cell in the eNB to which the new cell belongs, when the evaluation module outputs a new PCI value ^ ', check whether the new The PCI value satisfies the congruence relationship. If yes, the evaluation module is notified to perform, otherwise the new PCI value ^ ' is output as the recommended PCI value of the newly created cell.

The device according to claim 7, wherein the device further comprises: a prompting module, configured to prompt the OMC to create a cell of the cell to cause interference of the reference information of the neighboring cell.