CN103533656A - PCI (physical cell identification) allocation method suitable for low-speed MR (mobile relay) - Google Patents

Abstract

The invention relates to a PCI allocation method suitable for a low-speed MR, and belongs to the field of wireless communication. The method comprises the steps as follows: a PCI allocation detection list is configured and maintained at a macro base station terminal of each cell, and a state information list is configured and maintained at each MR terminal simultaneously; the MR determines an access cell B according to cell selection norm and performs signaling interaction with a macro base station of the target cell B, so that the cell switching is finished; the macro base station of the cell B performs matching search on PCI of the MR and a PCI allocation detection list managed by the macro base station of the cell B, and whether collision exists is detected; the MR performs PCI screening by utilizing the obtained allocation detection list managed by the macro base station of the cell B and the state information list, and performs priority ranking; M (M is equal to 1) PCIs with highest priority ranking are selected to be reported to the macro base station of the cell B; the PCIs are reallocated for the MR by the macro base station of the cell B according to the PCIs reported by the MR; and the MR and the macro base station of the cell B perform information updating correspondingly. With the adoption of the PCI allocation method suitable for the low-speed MR, the problems of PCI collision and confusion caused when the MR moves in multiple cells at a lower speed can be effectively solved, and the replacement times of the PCIs are reduced.

Description

A kind of Physical Cell Identifier distribution method that is applicable to low speed mobile relay

Technical field

The invention belongs to wireless communication field, the particularly PCI distribution method of a kind of MR, mobile communications network faces the future.

Technical background

Along with popularizing rapidly of smart mobile phone, wireless data is explosive growth, and network capacity demand significantly promotes.The single layer network being formed by macro base station, although good covering can be provided, but be difficult to solve the problem that network capacity significantly promotes, in order to tackle ever-increasing demand data, in network, needing to introduce more low power nodes and form multitiered network, is the inexorable trend of future mobile communication system development.

The low power nodes of introducing at present comprises remote radio (RRH), slight (Pico), Home eNodeB (HeNB) and the relaying (Relay) of standing.The return link of relaying is wireless, so dispose flexibly, can be used for coverage enhancement.At the3rd Generation Partnership Project(3GPP) technology defined the relaying of two types: Type I Relay(Class1 relaying) and Type II Relay(type 2 relayings).Type I Relay has independently cell ID, is exactly community independently for terminal.Type II Relay does not have oneself independently Physical Cell Identifier ，Bu Fa community public reference signal and physical down control signal.At the standardized trunk type of Rel-10, be static laying, the mobile relay of studying in Rel-11 (Mobile Relay, MR) is placed on high-speed railway roof.Yet the application of relaying can be not limited to this, needing the further current mobile relay of research is that user moves the scene of the application of (for example bus) with mobile relay low speed at low speed mobile ad-hoc.

It is that current mobile relay is studied a difficult problem urgently to be resolved hurrily that Physical Cell Identifier (PCI) distributes.PCI mono-has 504 values, and the position of mobile relay stationarity not, and the relay well or conflict and obscure with the PCI between all the other base stations of inevitably can being moved in the application scenarios of mobile relay causes the user cannot proper communication.The current PCI distribution method about base station is distributed mainly for the PCI of fixed base stations, the main principle of these distribution methods is that the current PCI having used is used in the base station to newly adding as far as possible, finally reach and use few PCI that tries one's best to complete PCI distribution to current all base stations, but the PCI that these methods can not be avoided mobile relay to switch between different districts and bring conflicts and obscures problem, therefore the PCI distribution method of these fixed base stations is not suitable for the application scenarios of low speed mobile relay, , and the current distribution method for mobile relay PCI need be carried out PCI replacing frequently, and need the collision problem between detection and fixed base stations PCI, therefore need to solve the PCI assignment problem of mobile relay.

Summary of the invention

The object of the invention is for solving the PCI allocative decision problem of mobile relay, a kind of Physical Cell Identifier distribution method that is applicable to low speed mobile relay is proposed, the method can effectively solve mobile relay with the conflict of PCI when moving in low velocity Duo community with obscure problem, can preferentially select the PCI of low collision probability in use procedure, effectively reduce PCI and changed number of times.

A kind of Physical Cell Identifier distribution method that is applicable to low speed mobile relay that the present invention proposes, is characterized in that, the method is that mobile relay (MR) distributes reserved PCI, for MR to the distribution of PCI and management; Specifically comprise the steps:

1) the macro base station end of Ge community configures and safeguards that PCI distributes detection list, for managing all PCI of this community, uses states, all PCI be labeled as with do not use; Each MR end configuration is simultaneously maintenance of state information table also, for recording this mobile relay in historical information and the real time information of motion process;

Described PCI distributes detection list to comprise table one, table two, and table one, table two are divided into PCI and do not use PCI two parts; The PCI allocation table that wherein table one is fixed base stations, table two is for keeping for the PCI list of MR;

The state information table of described MR comprises two parts: historical information duration, Reference Signal Received Power grade point;

2) MR, according to community selection criterion, determines the community that will access, and by X2 interface, carries out Signalling exchange with the macro base station of object community, completes community access; When having detected MR, the macro base station of community B enters this macro base station management area, the macro base station of community B carries out information interaction with the MR that enters into community B by X2 interface, whether the macro base station of community B differentiates this MR for opening first, if, the macro base station of community B is according to the PCI information of table two in managed detection list, from available PCI, choose a PCI and distribute to this MR, upgrade the distribution detection list of the macro base station of the state information Biao Ji community B in MR simultaneously, the PCI of this MR distributes end; The macro base station of ，Ze community B determines that this MR has carried out community switching if not, from other communities, is switched to community B, enters step 3);

3) macro base station of community B distributes table two in detection list with PCI, partly to carry out match search to the PCI of this MR and the own PCI managing, the PCI that detects this MR whether with community B in the PCI of all the other MR have collision; The PCI that the macro base station of match search Shi， community B is checked through this MR if carry out, for using PCI, is judged as and has conflict, enters step 4); Otherwise, not needing to carry out PCI renewal, the PCI of this MR distributes end;

4) macro base station of GaiMRYu community B carries out information interaction, obtains the information of detection list two of the macro base station end management of community B, enters step 5);

5) in the distribution detection list of the community B macro base station management that this MR utilization is obtained, by the RSRP value in PCI and state information table, do not carry out PCI screening, concrete screening process is:

5-1) by RSRP grade point > 0 PCI is never with getting rid of in PCI, checks and do not use whether in addition PCI, if exist, performs step 6), otherwise this MR re-starts PCI screening, execution step 5-2);

5-2) by RSRP grade point > 1 PCI is never with getting rid of in PCI, checks and do not use whether in addition PCI, if exist, performs step 6), otherwise this MR closes automatically, finishes PCI and distributes;

6) this MR, according to the PCI of the historical time in state information table and screening, carries out prioritization according to predefined criterion; Then select the M(M that prioritization is the highest >=1) individual PCI reports B macro base station ，Xiang community, community B macro base station and send PCI and distribute application;

7) PCI that the macro base station of community B reports according to this MR, for MR redistributes PCI; The macro base station corresponding informance of GaiMRJi community B upgrades, comprise this MR more the macro base station of new state information Biao， community B upgrade its table two.

Feature of the present invention and beneficial effect:

The method that the present invention adopts is the reserved a part of PCI of MR, avoids conflicting with the PCI of stationary nodes, and mobile relay is safeguarded a state information table simultaneously, when needs PCI changes, to macro base station, provides effective available PCI information, assists the PCI of base station to distribute.When MR carries out after the switching of community, macro base station under this MR need carry out PCI collision detection, if there is PCI collision problem, this MR and macro base station carry out information interaction, from the state information table of self maintained, according to the historical duration of the use of RSRP grade point and each PCI, screen good available PCI and report macro base station, macro base station is that MR distributes PCI according to this information.

The present invention puies forward the problem that PCI distribution method can effectively solve the mobile relay PCI conflict under low speed mobile context.The method is the reserved a part of PCI of mobile relay, can directly avoid like this mobile relay to conflict with the PCI between fixed base stations, the search complexity needing in the time of can reducing MR collision detection simultaneously.Simultaneously at this MR of mobile relay end configuration status table record, each PCI in motion process is used Reference Signal Received Power (the Reference Signal Receiving Power of historical time and adjacent MR thereof, RSRP) grade point, historical time is longer, represent to use this PCI to change number of times fewer, RSRP is larger, represents to use the probability of this PCI conflict larger.The selection foundation of upgrading as PCI accordingly, can reduce the PCI switching times of this MR in motion process, and this process converges to relatively-stationary several PCI the most at last, thereby effectively avoids the frequent replacing of PCI in MR moving process.

Accompanying drawing explanation

Fig. 1 is the FB(flow block) of the collocation method of Physical Cell Identifier of the present invention.

Fig. 2 is that macro base station is mobile relay (MR) collision detection and configuration flow block diagram.

Embodiment

A kind of Physical Cell Identifier distribution method that is applicable to low speed mobile relay that the present invention proposes by reference to the accompanying drawings and embodiment be described in detail as follows:

As shown in Figure 1, the method is MR(mobile relay to method of the present invention) distribute reserved PCI, for MR to the distribution of PCI and management; Specifically comprise the steps:

1) the macro base station end of Ge community configures and safeguards that PCI distributes detection list, for managing all PCI of this community, uses states, all PCI be labeled as with do not use; Each MR end configuration is simultaneously maintenance of state information table also, for recording this mobile relay in historical information and the real time information of motion process; The state information table particular content of the distribution detection list of macro base station end and MR end is as follows:

A) PCI distributes detection list to comprise table one, table two.Table one, table two are divided into A, B part, and A is partly for using PCI, and B is not partly for using PCI.The PCI allocation table that wherein table one is fixed base stations, this table is mainly the PCI distribution list of macro base station and all the other the fixing little base stations except MR.Table two is for keeping for the PCI list of MR.

B) the state information table of MR comprises two parts: historical information duration, Reference Signal Received Power (Reference Signal Receiving Power, RSRP) grade point.Historical information duration is to record the accumulated time that this mobile relay is used each PCI in motion process, RSRP grade point is according to RSRP measurement report mapping table, to carry out the value of grade mapping, at the RSRP grade point of mobile relay end record, receives the value that the corresponding RSRP value of all the other PCI is carried out grade mapping for this MR;

Historical information duration adopts Kbit record, if when the time of record surpasses Kbit (K > 0), all historical information durations n (n > 0) position that all moves right in table, overflows avoiding.RSRP grade point is to form RSRP grade point according to the scope of RSRP in TS36.133 and RSRP measurement report mapping table 1.

Table 1

Report value	Measured value	Unit
			RSRP_00	RSRP<-140	dBm
RSRP_01	-140<RSRP<-139	dBm
			RSRP_02	-139<RSRP<-138	dBm
……	……	……
			RSRP_95	-46<RSRP<-45	dBm
RSRP_96	-45<RSRP<-44	dBm
			RSRP_97	-44<RSRP	dBm

2) the historical information time longer, represent to use this PCI to change number of times fewer, RSRP is larger, represents to use the probability of this PCI conflict larger.The selection foundation of upgrading as PCI accordingly, can reduce the PCI switching times of this MR in motion process, and MR, according to community selection criterion, determines the community that will access, and by X2 interface, carries out Signalling exchange with the macro base station of object community, completes community access; When having detected MR, the macro base station of community B enters this macro base station management area, the macro base station of community B carries out information interaction with the MR that enters into community B by X2 interface, whether the macro base station of community B differentiates this MR for opening first, if, the macro base station of community B is according to the PCI information of table two in managed detection list, from available PCI, choose a PCI and distribute to this MR, upgrade the distribution detection list of the macro base station of the state information Biao Ji community B in MR simultaneously, the PCI of this MR distributes end; The macro base station of ，Ze community B determines that this MR has carried out community switching if not, from other communities, is switched to community B, enters step 3);

3) macro base station of community B distributes table two A in detection list to carry out match search to the PCI of this MR and the own PCI managing, the PCI that detects this MR whether with community B in the PCI of all the other MR have collision; The PCI that the macro base station of match search Shi， community B is checked through this MR if carry out, for using PCI, is judged as and has conflict, enters step 4); Otherwise, not needing to carry out PCI renewal, the PCI of this MR distributes end;

4) macro base station of GaiMRYu community B carries out information interaction, obtains the information of detection list two of the macro base station end management of community B, enters step 5);

5) in the distribution detection list of the community B macro base station management that this MR utilization is obtained, by the RSRP value in PCI and state information table, do not carry out PCI screening, concrete screening process is:

5-1) by RSRP grade point > 0 PCI is never with getting rid of in PCI, checks and do not use whether in addition PCI, if exist, performs step 6), otherwise this MR re-starts PCI screening, execution step 5-2);

5-2) by RSRP grade point > 1 PCI is never with getting rid of in PCI, checks and do not use whether in addition PCI, if exist, carries out 6), otherwise this MR closes automatically, finishes PCI and distributes;

6) if the PCI number that satisfies condition is t after screening, if t > 1, this MR carries out prioritization (priority of for example, growing up when historical is high) according to the PCI of the historical time in state information table and screening according to predefined criterion; Then select the M(M that prioritization is the highest >=1) individual PCI reports B macro base station ，Xiang community, community B macro base station and send PCI and distribute application; If t=1, does not carry out prioritization, directly this PCI is reported to the macro base station of community B

7) the PCI number M that the macro base station of community B reports according to this MR, carries out PCI distribution, if M > to choose at random a PCI be that MR redistributes PCI for the macro base station of 1 ，Ze community B; The macro base station of RuoM=1，Ze community B is distributed to this MR by this PCI; The macro base station corresponding informance of GaiMRJi community B upgrades, comprise this MR more the macro base station of new state information Biao， community B upgrade its table two.

Below lifting specific embodiment introduces in detail:

The present embodiment is arranged on city bus with this MR, and user is with the scene of MR low-speed motion, and the highest rate travel of this bus is lower than 30Km/h.

The present embodiment considers that urban area mobile relay is deployed on bus, and user is with the mobile scene of mobile relay.Consider the quantity of city bus, suppose that keeping for the PCI of MR is 30, meanwhile, according to RSRP measurement report mapping table, form RSRP grade point.The method comprises the following steps:

1) the macro base station end of Ge community is safeguarded and is upgraded a PCI distribution detection list, and MR safeguards and upgrades a state information table simultaneously.The distribution detection list of macro base station end is used states for managing all PCI of this community, by all PCI be labeled as with do not use.Simultaneously the method is that MR distributes reserved PCI, for distribution and the management of the PCI of MR, can effectively reduce like this search complexity of MR collision detection, can effectively avoid MR to conflict with the PCI of macro base station simultaneously.

PCI distributes detection list to comprise table one, table two.Table one, table two are divided into A, B part, and A is partly for using PCI, and B is not partly for using PCI.The PCI allocation table that wherein table one is fixed base stations, this table is mainly the PCI distribution list of macro base station and all the other the fixing little base stations except MR.Table two is for keeping for the PCI list of MR.

The state information table that MR arranges comprises two parts: historical information duration, RSRP grade point.Historical information duration is to record the accumulated time that this mobile relay is used each PCI in motion process, RSRP grade point is to carry out grade mapping according to RSRP measurement report mapping table, and the RSRP grade point recording at mobile relay end carries out grade mapping for this MR receives the corresponding RSRP value of all the other PCI.

PCI record	RSRP grade point	Historical duration
			PCI1	R1	T1
PCI2	R2	T2
			……	……	……

Historical information duration adopts Kbit record, if when the time of record surpasses Kbit, in table, all historical information durations all move right 1, overflows avoiding.Suppose that every 1s duration information increases by 1, K=16, when the historical duration of certain PCI of mobile relay record reaches 65535(2 ¹⁶-1), during s, all historical duration of this MR record moves right 1.According to the scope of RSRP in TS36.133 and mapping table, form RSRP grade point simultaneously.As:

RSRP<-110dBm, RSRP grade is 0;-110dBm≤RSRP<-90dBm, RSRP grade point is 1;-90dBm≤RSRP<-70dBm, RSRP grade point is 2; RSRP>=-70dBm, RSRP grade point is 3;

2) if macro base station has detected MR, enter this macro base station management area, this MR and this macro base station carry out information interaction by X2 interface, and whether macro base station differentiates this MR for opening first.If so, this macro base station, according to the PCI information of table two in managed detection list, is chosen a PCI and is distributed to this MR from available PCI, upgrades the distribution detection list of state information table and the macro base station of MR simultaneously, and the PCI of this MR distributes end.If not, the macro base station of community B determines that this MR has carried out community switching, from other communities, is switched to community B, enters step 3);

3) B macro base station in community distributes table two A in detection list to carry out match search to the PCI of this MR and the own PCI managing, and the PCI that detects this MR whether PCI of remaining mobile relay of He Gai community has collision; If while carrying out match search, macro base station is checked through the PCI of this MR for using PCI, is judged as and has conflict, enters step 4); Otherwise, not needing to carry out PCI renewal, the PCI of this MR distributes end;

4) macro base station of GaiMRYu community B carries out information interaction, obtains the information of detection list two of the macro base station end management of community B, enters step 5);

5) in the distribution detection list of the community B macro base station management that this MR utilization is obtained, by the RSRP value in PCI and state information table, do not carry out PCI screening, concrete screening process is:

5-1) by RSRP grade point > 0 PCI is never with getting rid of in PCI, checks and do not use whether in addition PCI, if exist, performs step 6), otherwise this MR re-starts PCI screening, execution step 5-2);

5-2) by RSRP grade point > 1 PCI is never with getting rid of in PCI, checks and do not use whether in addition PCI, if exist, carry out (6), otherwise this MR closes automatically, and finish PCI and distribute.

6) suppose that the PCI number satisfying condition is t after screening, if t > 1, this MR carries out prioritization according to the PCI of the historical time in state information table and screening according to presetting criterion, and the priority of growing up while setting history in the present embodiment is high; Then select the M(M that prioritization is the highest >=1) individual PCI reports B macro base station ，Xiang community, community B macro base station and send PCI and distribute application, as get M=2; If t=1, this MR directly reports this PCI community B macro base station

7) the PCI number that the macro base station of community B reports according to this MR is carried out PCI distribution, if the macro base station of M > 1 ，Ze community B is chosen a PCI at random, is that MR redistributes PCI; The macro base station of RuoM=1，Ze community B is distributed to this MR by this PCI.This MR and affiliated macro base station corresponding informance thereof upgrade simultaneously.As MR new state information table more, comprise the historical duration of the PCI of record, RSRP grade point.If historical duration surpasses setting range, the method providing according to step 1, all historical duration of this MR record moves right 1.Macro base station upgrades its table two simultaneously.

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.

Claims (1)

1. a Physical Cell Identifier distribution method that is applicable to low speed mobile relay, is characterized in that, the method is that mobile relay (MR) distributes reserved PCI, for MR to the distribution of PCI and management; Specifically comprise the steps:

1) the macro base station end of Ge community configures and safeguards that PCI distributes detection list, for managing all PCI of this community, uses states, all PCI be labeled as with do not use; Each MR end configuration is simultaneously maintenance of state information table also, for recording this mobile relay in historical information and the real time information of motion process;

Described PCI distributes detection list to comprise table one, table two, and table one, table two are divided into PCI and do not use PCI two parts; The PCI allocation table that wherein table one is fixed base stations, table two is for keeping for the PCI list of MR;

The state information table of described MR comprises two parts: historical information duration, Reference Signal Received Power grade point;

2) MR, according to community selection criterion, determines the community that will access, and by X2 interface, carries out Signalling exchange with the macro base station of object community, completes community and switches; When having detected MR, the macro base station of community B enters this macro base station management area, the macro base station of community B carries out information interaction with the MR that enters into community B by X2 interface, whether the macro base station of community B differentiates this MR for opening first, if, the macro base station of community B is according to the PCI information of table two in managed detection list, from available PCI, choose a PCI and distribute to this MR, upgrade the distribution detection list of the macro base station of the state information Biao Ji community B in MR simultaneously, the PCI of this MR distributes end; The macro base station of ，Ze community B determines that this MR has carried out community switching if not, from other communities, is switched to community B, enters step 3);

3) macro base station of community B distributes table two in detection list with PCI, partly to carry out match search to the PCI of this MR and the own PCI managing, the PCI that detects this MR whether with community B in the PCI of all the other MR have collision; The PCI that the macro base station of match search Shi， community B is checked through this MR if carry out, for using PCI, is judged as and has conflict, enters step 4); Otherwise, not needing to carry out PCI renewal, the PCI of this MR distributes end;

4) macro base station of GaiMRYu community B carries out information interaction, obtains the information of detection list two of the macro base station end management of community B, enters step 5);

5) in the distribution detection list of the community B macro base station management that this MR utilization is obtained, by the RSRP value in PCI and state information table, do not carry out PCI screening, concrete screening process is:

5-1) by RSRP grade point > 0 PCI is never with getting rid of in PCI, checks and do not use whether in addition PCI, if exist, performs step 6), otherwise this MR re-starts PCI screening, execution step 5-2);

5-2) by RSRP grade point > 1 PCI is never with getting rid of in PCI, checks and do not use whether in addition PCI, if exist, performs step 6), otherwise this MR closes automatically, finishes PCI and distributes;

6) this MR carries out prioritization according to the PCI of the historical time in state information table and screening according to predefined criterion; Then select the M(M that prioritization is the highest >=1) individual PCI reports B macro base station ，Xiang community, community B macro base station and send PCI and distribute application;

7) PCI that the macro base station of community B reports according to this MR, for MR redistributes PCI; The macro base station corresponding informance of GaiMRJi community B upgrades, comprise this MR more the macro base station of new state information Biao， community B upgrade its table two.

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