CN101583175B - Target NeNB cell identity method based on neighbor cell message in LTE-advanced network - Google Patents

Abstract

The invention relates to a target NeNB cell identity method based on a neighbor cell message in an LTE-advanced network when improving PCI confusion. The invention comprises a substantial idea that the PCI of the target NeNB cell is combined with the PCI of the neighbor NeNB cell thereof to be taken as the characteristic of the target HeNB under the condition that the target NeNB cell PCI is confused with the other HeNB cell, so as to improve the identification probability of the target HeNB cell.

Description

A kind of target HeNB cell recognition method that is used for the LTE-advanced network based on neighbor cell message

Technical field

The present invention relates to the mobile communication technology field, particularly a kind of method that is used for target HeNB cell identification in LTE-advanced (LTE-A, Long-termEvolution advanced, the further evolution of the 3GPP LTE) network belongs to moving communicating field.

Background technology

In order to accelerate the process of Cell searching, macrocell (Macro Cell) need synchronizing channel periodically broadcast this sub-district Physical Cell Identifier (Physical Cell Identifier, PCI).When Cell searching, (UserEquipment UE) does not know any information of macrocell to subscriber equipment, so PCI adopts and do not have the Serial No. of scrambling to represent, this has just limited the quantity of available PCI, and LTE regulation PCI adds up to 504.PCI in fact only has local meaning, for can the unique sub-district of sign of the overall situation, LTE has defined E-UTRAN sub-district overall identification (E-UTRAN Cell GlobalId, ECGI), and be included in system information block (System Information Block, SIB) (Dynamic Broadcast Channel DBCH) goes up periodic broadcasting at Dynamic Broadcast Channel in.

Though sub-district of the sign that ECGI can be unique, but, UE needs the long time usually because obtaining the ECGI of a sub-district, therefore switch when needing to determine Target cell fast to other sub-district from macrocell at UE, use the PCI of Target cell to determine Target cell usually.Macrocell is preserved a neighborhood table (Neighbor Relation table, NRT), write down its neighbours' PCI and ECGI, and foundation mapping between PCI and ECGI, like this when UE from macrocell when Target cell switches, macrocell just can be determined Target cell rapidly according to the Target cell PCI of UE report.

LTE defined Home eNodeB (Home Evolved Node B, HeNB).When the quantity of HeNB in the macrocell surpassed 504, PCI obscured unavoidably, and the PCI that two or more HeNB are promptly arranged is identical, can occur the phenomenon of the corresponding a plurality of ECGI of a PCI at this moment in the neighborhood table of macrocell.When switch the HeNB sub-district, just may directly determine target HeNB sub-district from macrocell at UE like this, thereby bring bigger influence to switching according to PCI.Therefore, when PCI obscured, how unique and definite fast Target cell was a problem that merits attention according to the PCI of target HeNB sub-district, existing at present following several schemes:

Scheme one: macrocell indication UE reads system information block (SIB) information of Target cell, obtains the ECGI of sub-district, and eNB judges Target cell according to ECGI.

Scheme two: the relevant HeNB that the macrocell notice has PCI to obscure carries out to switch and prepares, and normally sends switching command then.

Scheme three: the auxiliary affirmation of the fingerprint/positional information Target cell that utilizes HeNB.

Scheme four: utilize the auxiliary affirmation of the difference Target cell between HeNB and the macrocell frame timing.Suppose HeNB and macrocell, time between the HeNB is all asynchronous, and the delivery time of the physical frame of HeNB and macrocell just have a time difference like this, and for different HeNB, this time difference also is at random, therefore can utilize this information to assist and confirm Target cell.

In the scheme one, UE need read SIB and obtain ECGI, and this just needs 160ms at least, under the active pattern, postpones excessive cause easily the Radio Link inefficacy (Radio Link Failure, RLF); In the scheme two, all be the UE reserved resource, at this moment can cause the waste of resource, can the HeNB of inadequate resource own be made a big impact owing to need all relevant HeNB of PCI conflict.Scheme three needs UE can obtain fingerprint/positional information of HeNB, and this can introduce extra expense.For scheme four, the transmitting time difference that how to obtain physical frame between HeNB and the macrocell is a problem, and macrocell and HeNB be when using the TDD technology, and this scheme is invalid.

Summary of the invention

The technical problem to be solved in the present invention: overcome the deficiencies in the prior art, the method of target HeNB cell identification rate when proposing a kind of raising PCI and obscuring based on neighbor cell message, it realizes simple, do not need to increase the overhead of hardware, when PCI obscures, have the identification probability of very high target HeNB sub-district.

Note target HeNB sub-district PCI is x, and the PCI of certain neighbours HeNB sub-district is y.Owing to exist PCI to obscure, eNB may be according to the unique HeNB sub-district that sets the goal really of x, but can utilize y further to determine target HeNB sub-district or the scope of dwindling target HeNB sub-district this moment.If the PCI quantity that the HeNB sub-district allows to use is N, the maximum occurrences of N is 504, supposes to have in the macrocell m HeNB sub-district identical with the PCI of target HeNB sub-district, and wherein each HeNB has k again among this m HeNB _i(i=1,2 ..., m) individual neighbours, then the probability according to x and the unique definite target HeNB of y energy sub-district is:

$P=1-\frac{\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{k}_i}{N-1}---\left(1\right)$

For example work as m=3, k ₁=k ₂=k ₃=4 o'clock, the PCI that 3 HeNB sub-districts are promptly arranged was identical with PCI when Target cell, and each HeNB has 4 neighbours, then according to x and y can unique definite target HeNB probability be 1-12/ (N-1), the value of N is 504 o'clock, this probability is more than 96%.

Based on this thought, the method for target HeNB cell identification rate when the present invention proposes a kind of raising PCI based on neighbor cell message and obscures.In this method, after UE searches target HeNB sub-district, send measurement report, contain the PCI of target HeNB sub-district in the measurement report to macrocell.If macrocell can't be according to the unique definite target HeNB of the PCI sub-district of target HeNB sub-district, then a neighbours' of the target HeNB sub-district that can provide according to UE PCI information is further determined target HeNB sub-district.

The key of implementing this method has two: the one, and macrocell need be known the neighborhood between all HeNB sub-districts in the sub-district, this can obtain from the OAM module of macrocell.The 2nd, UE need know the PCI of a neighbours HeNB sub-district of target HeNB sub-district.UE if can detect the synchronizing channel (SCH) of other HeNB sub-districts and obtain their PCI, then thinks the neighbours that these HeNB sub-districts are target HeNB sub-districts in the process of ferret out HeNB sub-district; If UE can only obtain the SCH of target HeNB sub-district, then need be by means of the historical metrical information of UE---UE preserves the PCI information of its HeNB sub-district of measuring recently, if this information is in the predefined term of validity, then think the neighbours that this HeNB sub-district is target HeNB sub-district.

If UE fails to find the existence of the neighbours HeNB sub-district of target HeNB sub-district, there is not historical metrical information yet, then handle according to normal operation.

Description of drawings

Fig. 1 is the enforcement scene graph of the embodiment of the invention one;

Fig. 2 is the message flow chart of the embodiment of the invention one;

Fig. 3 is the enforcement scene graph of the embodiment of the invention two;

Fig. 4 is the message flow chart of the embodiment of the invention two.

Embodiment

Illustrate implementation method of the present invention below in conjunction with accompanying drawing and two specific embodiments of the present invention.

Fig. 1 provides the enforcement scene of embodiments of the invention one, and UE can search two HeNB sub-districts simultaneously.Fig. 2 has provided under this scene, implements Message Processing flow process of the present invention:

1) UE searches for the HeNB sub-district that exists around it, obtains relevant information such as PCI, the signal strength signal intensity etc. of two HeNB sub-districts;

2) UE is with 1) in the information measured be included in the measurement report, send to macrocell;

3) after macrocell receives the measurement report of UE transmission, at first determine target HeNB (how determining that target HeNB is not the content that the present invention pays close attention to), another HeNB that relates in the measurement report thinks the neighbours of target HeNB.Macrocell is searched target HeNB according to the PCI of target HeNB in NRT then, and is unique as Query Result, then enters 8); Otherwise Query Result is designated as candidate target HeNB collection, enters 4);

4) whether to have PCI in the NRT of the grand target HeNB of all candidates sub-district inquiry be the clauses and subclauses of y to macrocell, further to determine target HeNB sub-district.If can unique definite target HeNB, then enter 8); Otherwise enter 5);

5) macrocell indication UE further reads the ECGI of target HeNB;

6) UE reads the ECGI of target HeNB from auxilliary broadcast channel;

7) UE is to the ECGI of macrocell reporting objectives HeNB;

8) macrocell sends handoff request to target HeNB.

Fig. 3 provides the enforcement scene of embodiments of the invention one, and UE is merely able to search a HeNB sub-district.Fig. 4 has provided under this scene, implements Message Processing flow process of the present invention:

1) UE searches for the HeNB sub-district that exists around it, obtains relevant information such as PCI, the signal strength signal intensity etc. of target HeNB sub-district;

2) UE is with 1) in the information measured be included in the measurement report, send to macrocell;

3) after macrocell received the measurement report of UE transmission, at first the PCI according to target HeNB searches target HeNB in NRT, and was unique as Query Result, then enters 8); Otherwise Query Result is designated as candidate target HeNB collection, enters 4);

4) PCI of macrocell indication neighbours HeNB sub-district, UE reporting objectives HeNB sub-district or read the ECGI of target HeNB;

5) UE inquires about the PCI information of its last HeNB sub-district of measuring, in the predefined term of validity, then thinks the neighbours that this HeNB sub-district is target HeNB sub-district as if this information, with the report macrocell of this sub-district; Otherwise enter 8);

6) whether to have PCI in the NRT of the grand target HeNB of all candidates sub-district inquiry be the clauses and subclauses of y to macrocell, further to determine target HeNB sub-district.If can unique definite target HeNB, then enter 10); Otherwise enter 7);

7) macrocell indication UE further reads the ECGI of target HeNB;

8) UE reads the ECGI of target HeNB from auxilliary broadcast channel;

9) UE is to the ECGI of macrocell reporting objectives HeNB;

10) macrocell sends handoff request to target HeNB.

Claims (1)

1.LTE-advanced the method for target HeNB cell identification rate when a kind of raising Physical Cell Identifier PCI based on neighbor cell message obscures in the network is characterized in that:

Under the situation that the Physical Cell Identifier PCI of target HeNB sub-district and other HeNB sub-districts obscures, the Physical Cell Identifier PCI of Physical Cell Identifier PCI neighbours HeNB some with it sub-district of target HeNB sub-district is joined together as the feature of target HeNB, to improve the identification probability of target HeNB sub-district;

When UE can search target HeNB sub-district and other HeNB sub-district simultaneously, think that then these HeNB sub-districts are neighborhoods;

When UE was merely able to search a target HeNB sub-district, UE inquired about the PCI information of its last HeNB sub-district of measuring, in the predefined term of validity, then thought the neighbours that this HeNB sub-district is target HeNB sub-district as if this information;

Whether described target HeNB sub-district further exists PCI to determine for the clauses and subclauses of the PCI of neighbours HeNB sub-district by inquiry in the neighborhood table NRT of the grand target HeNB of all candidates sub-district; The grand target HeNB of described candidate sub-district is for searching target HeNB according to the PCI of target HeNB in NRT, when Query Result results set only for the moment not.

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