CN104640149A - Self-adaptive cell expansion and bias adjusting method used in heterogeneous network - Google Patents

Abstract

The invention discloses a self-adaptive cell expansion and bias adjusting method used in a TD-LET-A heterogeneous network. The self-adaptive cell expansion and bias adjusting method comprises the following steps: dividing users in a pico cell into CRE users and center users, and dividing users in a macro cell into boundary users and center users; regulating a cell offset value according to a load balancing condition between the macro cell and the pico cell, if the load of the macro cell is relatively heavy, successively selecting out, by the macro cell, the users, that can obtain a higher SINR (signal to interference and noise ratio) compared with that obtained when the users are accessed to the macro cell to which the users belong currently, among the boundary users if the users are accessed into the pico cell, updating the cell offset value to a required cell offset value by the existing user for accessing to a pre-selected pico cell; if the load of the pico cell is relatively heavy, successively selecting out, by the pico cell, the users, that can obtain a higher a higher SINR compared with that obtained when the users are accessed to the micro cell to which the users belong currently, among the CRE users if the users are accessed into the macro cell, updating the cell offset value to a required cell offset value by the existing user for accessing to a pre-selected macro cell, balancing the load between the macro cell and the pico cell by iteratively adjusting the cell offset value, thereby finally achieving the purpose of dynamically adjusting the cell offset value.

Description

A kind of for the biased method of adjustment of adaptive cell expansion in heterogeneous network

Technical field

The present invention relates to a kind of for the biased method of adjustment of adaptive cell expansion in TD-LTE-A heterogeneous network, belong to mobile communication technology field.

Background technology

In order to promote the overall performance of network, be conceived to improve the spectrum efficiency in per unit region, heterogeneous network propose by TD-LTE-A standardization body, become one of key technology considered in TD-LTE-A standard formulation.Heterogeneous network adopts the base node of different radio access technologies to form by some, and they have different capacity, constraints and function.In TD-LTE-A system, classical macro-cellular newly can add far-end radio node (RRH) and some low power nodes, as comprised Pico cell, Home eNodeB and relaying under covering.The deployment of new node effectively can alleviate macrocellular load, improves the covering quality of specific region, improve the performance of edge customer.

The introducing of heterogeneous network is faced with some allowed important technical challenges such as such as self-organizing, self-optimizing, backhaul design, switching, presence of intercell interference, and the problem of inter-cell interference wherein brought because network topology structure changes is particularly important.Under macrocellular and microcellulor scene, the terminal use being in grand (macro) cell edge can cause larger uplink interference to micro-(pico) community.Range expansion technique (Range Expansion) can address this problem, but there are some defects: on the one hand, when bias bias is too little, can cause insufficient transfer of the load from macro station to base station; On the other hand, if bias bias is too large, the SINR of PUE may can not meet the decoding minimum threshold of downlink physical control channel (PDCCH).For this reason, need a kind of effective method, overcome the shortcoming of above range expansion technique, ensure that macro station shifts to the load of base station, reduce the descending interference that Microcell edge termination user is subject to simultaneously, improve the total capacity of system.

Summary of the invention

Goal of the invention: in order to overcome the deficiencies in the prior art, the present invention proposes a kind of adaptive cell and be biased method of adjustment, optimized community can be automatically selected to be biased in the method, thus on effective basis of improving the throughput of heterogeneous network small area edge customer, reach the load balancing between macrocell and Microcell.

Technical scheme: a kind of for the biased method of adjustment of adaptive cell expansion in TD-LTE-A heterogeneous network, after initial cell is biased, the cycle performs following step:

The first step: the parameter that the signal receiving quality based on reporting of user is relevant, user in each Microcell is divided into spreading range region, Microcell (Cell range expansion, CRE) user and central user, and, the user in each macrocell is divided into macrocell boundary user and central user;

Second step: select the user that can cut Microcell j in it in the boundary user of macrocell i, and calculate corresponding community bias, by user and the set of corresponding bias composition in the CRE user of Microcell j, select the user that can cut macrocell i, and calculate corresponding community bias, by user and the set of corresponding bias composition wherein, i ∈ Ω _macro, j ∈ Λ _{macro, i}, Ω _macrofor macro base station set all in network, Λ _{macro, i}for the micro-collection of base stations in macro base station i coverage;

3rd step: the resources occupation rate calculating each macrocell and each Microcell, and the ratio ω calculating the resources occupation rate of Microcell j in macrocell i and the resources occupation rate of macrocell i _i,j;

4th step: according to ω _i,jthe community bias of value adjustment Microcell j, if ω _i,jwithin the scope preset, i.e. ω _i,j∈ [ω ₀, ω ₁], then terminate the biased adjustment in community of Microcell j; If ω _i,jbe less than default range lower limit, i.e. ω _i,j< ω ₀, then the 5th step is entered; If ω _i,jbe greater than default range limit, i.e. ω _i,j> ω ₁, then the 6th step is entered; Wherein, [ω ₀, ω ₁] to be operator arranged according to network condition a threshold interval representing the non-load balanced case between macrocell and Microcell.

5th step: according to bias in set order from small to large takes out still untreated user successively, and after judging that active user k switches Microcell j, if required business demand can be met in community, then the biased of Microcell j is adjusted to the active user k of middle storage cuts the bias needed for the j of Microcell, and user carries out reselecting of Serving cell according to the bias after adjustment and accesses, and returns the 3rd step; If can not meet, terminate the biased adjustment in community of Microcell j;

6th step: according to bias in set order from small to large takes out still untreated user successively, and after judging that active user k switches macrocell, if required business demand can be met in macrocell, then the community of Microcell j is biased is adjusted to the active user k of middle storage cuts the bias needed for macrocell i, and user carries out reselecting of Serving cell according to the bias after adjustment and accesses, and returns the 3rd step, if can not meet, terminates the biased adjustment in community of Microcell j.

Further, in the described first step, the user in each Microcell is divided in the concrete steps of Microcell CRE user and central user, comprises:

The Reference Signal Received Power (Reference Signal Receiving Power, RSRP) from macro base station and the micro-base station of current home that Microcell all reporting of user measurement obtains;

Microcell base station after receiving the RSRP measurement result belonging to all users in this community, according to $\mathrm{Pico}-\mathrm{UE}=\left\{\begin{array}{cc}\mathrm{CRE}-\mathrm{UE}\&LeftArrow;\mathrm{ABS},& {\mathrm{RSRP}}_{\mathrm{serve}}^{\mathrm{Pico}}<{\mathrm{RSRP}}_{\max }^{\mathrm{Macro}}\&le;{\mathrm{RSRP}}_{\mathrm{serve}}^{\mathrm{Pico}}+\mathrm{Bias}\\ \mathrm{Center}-\mathrm{UE}\&LeftArrow;\mathrm{non}-\mathrm{ABS},& {\mathrm{RSRP}}_{\max }^{\mathrm{Marcro}}\&le;{\mathrm{RSRP}}_{\mathrm{serve}}^{\mathrm{Pico}}\end{array}\right.$ [rule 1]

Divide and dispatch the user in its community, by Microcell CRE user (CRE-UE) scheduling on ABS (almost blank subframe), by Microcell central user (Center-UE) scheduling on non-ABS; Wherein, for in the Microcell reporting of user data that base station receives from the Reference Signal Received Power that the interference of all macro base stations is the strongest, namely base station select that this Microcell user receives from the maximum in the RSRP of all macro base stations; for the Reference Signal Received Power from the micro-base station of current home in the Microcell reporting of user data that base station receives.CRE user and Microcell central user are not the Region dividing in physical significance.

Further, in the described first step, the user in each macrocell is divided in the concrete steps of macrocell boundary user and central user, comprises:

The RSRP from current home macro base station that all reporting of user measurements of macrocell obtain and Reference Signal Received Quality (Reference Signal Receiving Quality, RSRQ);

Macro cell base station, after receiving the RSRP measurement result belonging to all users in this community, is selected N number of macrocell user that RSRP is minimum, is designated as select N number of user that RSRQ is minimum, be designated as according to

[rule 2]

Select macrocell boundary user, wherein, N is the positive integer arranged according to network condition, and object is to rationally select the second-rate user of macro-cell signals.

Further, in the boundary user of each macrocell, in described second step, select the user that can cut Microcell in it, and calculate in the concrete steps of corresponding community bias, comprising:

Macro base station i travels through its boundary user, i ∈ Ω _macro, Ω _macrofor macro base station set all in network, according to

${\mathrm{RSRP}}_k^{\mathrm{Pico},j}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Pico}},l\&NotEqual;j}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Pico},l}>{\mathrm{RSRP}}_k^{\mathrm{Marcro},i}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Macro}},l\&NotEqual;i}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Macro},l}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Pico}}}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Pico},l}$ [rule 3]

If judge, active user k accesses Microcell j and whether can obtain the SINR higher than access current home macrocell i; If can, according to

${\mathrm{bias}}_k^{\mathrm{Pico},j}={\mathrm{RSRP}}_k^{\mathrm{Macro},i}-{\mathrm{RSRP}}_k^{\mathrm{Pico},j}+\mathrm{\&Delta;}$ [rule 4]

Calculate active user k to cut the community bias needed for this preselected Microcell j, by this user and the community that calculates is biased is designated as

According to

$\begin{array}{c}{\mathrm{\&Omega;}}_{\mathrm{macro}->\mathrm{pico}}^{i->j}=\{({\mathrm{UE}}_l,{\mathrm{bias}}_l^{\mathrm{Pico},j}),({\mathrm{UE}}_m,{\mathrm{bias}}_m^{\mathrm{Pico},j}).......({\mathrm{UE}}_n,{\mathrm{bias}}_n^{\mathrm{Pico},j}).......({\mathrm{UE}}_q,{\mathrm{bias}}_q^{\mathrm{Pico},j}),{\mathrm{UE}}_r,{\mathrm{bias}}_r^{\mathrm{Pico},j}\}\\ s.t{\mathrm{bias}}_l^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_m^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_n^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_q^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_r^{\mathrm{Pico},j}\end{array}$

[rule 5]

Income set wherein, j ∈ Λ _{macro, i}, Λ _{macro, i}represent the micro-collection of base stations in macro base station i coverage, Ω _picofor micro-collection of base stations all in network, represent the RSRP that user k receives from macro base station i, represent the RSRP that user k receives from the micro-base station j in macro base station i coverage, Δ be of arranging according to network condition on the occasion of, object ensures that new bias makes user k handover success.

Further, in the CRE user of each Microcell, in described second step, select the user that can cut macrocell, and calculate in the concrete steps of corresponding community bias, comprising:

Micro-base station j in macro base station i coverage travels through its CRE user, i ∈ Ω _macro, j ∈ Λ _{macro, i}, Ω _macrofor macro base station set all in network, Λ _{macro, i}for the micro-collection of base stations in macro base station i coverage, according to

${\mathrm{RSRP}}_k^{\mathrm{Pico},j}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Pico}},l\&NotEqual;j}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Pico},l}<{\mathrm{RSRP}}_k^{\mathrm{Macro},i}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Macro}},l\&NotEqual;i}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Macro},l}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Pico}}}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Pico},l}$ [rule 6]

If judge, active user k accesses macrocell i and whether can obtain the Signal Interference and Noise Ratio (Signal-to-Interference and Noise Ratio, SINR) higher than access current home Microcell j; If can, according to

${\mathrm{bias}}_k^{\mathrm{Pico},j}={\mathrm{RSRP}}_k^{\mathrm{Macro},i}-{\mathrm{RSRP}}_k^{\mathrm{Pico},j}-\mathrm{\&Delta;}$ [rule 7]

Calculating active user k to cut the community bias needed for preselected macrocell i, this user and respective cell being biased and being designated as

According to

$\begin{array}{c}{\mathrm{\&Omega;}}_{\mathrm{pico}->\mathrm{macro}}^{j->i}=\{({\mathrm{UE}}_l,{\mathrm{bias}}_l^{\mathrm{Pico},j}),({\mathrm{UE}}_m,{\mathrm{bias}}_m^{\mathrm{Pico},j}).......({\mathrm{UE}}_n,{\mathrm{bias}}_n^{\mathrm{Pico},j}).......({\mathrm{UE}}_q,{\mathrm{bias}}_q^{\mathrm{Pico},j}),{\mathrm{UE}}_r,{\mathrm{bias}}_r^{\mathrm{Pico},j}\}\\ s.t{\mathrm{bias}}_l^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_m^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_n^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_q^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_r^{\mathrm{Pico},j}\end{array}$

[rule 8]

Income set wherein, represent the RSRP that user k receives from micro-base station j, represent the RSRP that user k receives from macro base station i, Δ be of arranging according to network condition on the occasion of, object ensures that new bias makes user k handover success.

Further, calculate in described 4th step macrocell i resources occupation rate according to rule be:

${\mathrm{\&eta;}}_i^{\mathrm{macro}}=\frac{\underset{k\&Element;{\mathrm{\&Omega;}}_{\mathrm{macro}}^i}{\mathrm{\&Sigma;}}{N}_k^{\mathrm{macro}}}{N_{\mathrm{PRB}}^{\mathrm{macro}}}$ [rule 9]

Wherein, for the user of macrocell i gathers; represent the resource block number needed for a kth user of current macro cell; represent the resource block number that current macro cell has.

Calculate Microcell j resources occupation rate according to rule be

${\mathrm{\&eta;}}_j^{\mathrm{pico}}=\frac{\underset{k\&Element;{\mathrm{\&Omega;}}_{\mathrm{pico}}^j}{\mathrm{\&Sigma;}}{N}_k^{\mathrm{pico}}}{N_{\mathrm{PRB}}^{\mathrm{pico}}}$ [rule 10]

Wherein, for the user of Microcell j in macrocell i gathers; represent the resource block number needed for a kth user of current micro cell; represent the resource block number that Microcell has.

Further, the ratio calculating the resources occupation rate of Microcell j in macrocell i and the resources occupation rate of macrocell i in described 4th step according to rule be:

${\mathrm{\&omega;}}_{i,j}=\frac{{\mathrm{\&eta;}}_j^{\mathrm{pico}}}{{\mathrm{\&eta;}}_i^{\mathrm{macro}}}$ [rule 11]

Further, the described first step ~ the 6th step is according to cycle T=N*T _framerepeat, the biased adjustment of all micro-base stations synchronously performs; Wherein T _framerepresenting the time of a TD-LTE complete radio frames, is 10*TTI; TTI represents Transmission Time Interval, is 1ms; N is positive integer, represent the T that expansion biased method of adjustment adjustment cycle in adaptive cell comprises _framenumber, value can be arranged according to real network situation, and desirable scope is [1,20].

Beneficial effect: provided by the invention a kind of for the biased method of adjustment of adaptive cell expansion in TD-LTE-A heterogeneous network, first, the parameter relevant with signal receiving quality from macro base station and micro-base station that grand/Microcell reporting of user measurement obtains, in order to macrocell user to be divided into macrocell central user and macrocell edge customer, Microcell user is divided into Microcell CRE user and Microcell central user; Then, according to the load balance situation adjustment community bias between macrocell and Microcell, if macrocell heavier loads, if macrocell is selected in boundary user successively access the user that Microcell can obtain SINR higher than access current home macrocell, community is biased and is updated to active user to cut the community bias needed for this preselected Microcell, successively macrocell boundary user is unloaded to Microcell, until the load balancing between macrocell and Microcell; If micro-cell load is heavier, if Microcell is selected in CRE user successively access the user that macrocell can obtain the SINR higher than access current home Microcell, community is biased and is updated to active user to cut the community bias needed for this preselected macrocell, successively Microcell CRE user is cut macrocell, until the load balancing between macrocell and Microcell.Balance the load between macrocell and Microcell by iteration adjustment community bias, finally reach the target that dynamic community adjusting is biased.Thus while the average throughput of the system of maintenance, the effective throughput improving heterogeneous network small area edge customer.

Accompanying drawing explanation

Fig. 1 is flow chart of the present invention.

Fig. 2 is communication system architecture scene graph of the present invention.

Embodiment

It is a kind of for the biased method of adjustment of adaptive cell expansion in TD-LTE-A heterogeneous network that the present invention proposes, optimized community can be automatically selected to be biased, thus on effective basis of improving the throughput of heterogeneous network small area edge customer, reach the load balancing between macrocell and Microcell.

Below in conjunction with embodiment, this programme is made further instructions.

Embodiment one

Construct a TD-LTE-Advanced HetNet network as shown in Figure 2, one has 7 macrocells, has 2 Microcells in each macrocell coverage area.The frequency duplex factor as one of minizone is 1.Each Physical Resource Block bandwidth is 180kHz, and the distance between adjacent macro cell is 500 meters.In this example, each macrocell is uniform-distribution with 40 users, and Cell Center User and cell edge area user are than for 3:1, and wherein user centered by No. 1-30, No. 31-40 is edge customer.It is 3dB that community is biased initial value.Other important parameter in system is as shown in table 1 below:

Table 1: the system parameters in embodiment one

As shown in Figure 1, it is a kind of for the biased method of adjustment of adaptive cell expansion in TD-LTE-A heterogeneous network that the embodiment of the present invention provides, and after initial cell is biased, the cycle performs following step:

The first step: the Reference Signal Received Power (RSRP from all macro base stations and the micro-base station of current home that Microcell all reporting of user measurement obtains, Reference Signal Receiving Power), after micro-base station receives and belongs to the measurement result of all users in this community, according to

$\mathrm{Pico}-\mathrm{UE}=\left\{\begin{array}{cc}\mathrm{CRE}-\mathrm{UE}\&LeftArrow;\mathrm{ABS},& {\mathrm{RSRP}}_{\mathrm{serve}}^{\mathrm{Pico}}<{\mathrm{RSRP}}_{\max }^{\mathrm{Macro}}\&le;{\mathrm{RSRP}}_{\mathrm{serve}}^{\mathrm{Pico}}+\mathrm{Bias}\\ \mathrm{Center}-\mathrm{UE}\&LeftArrow;\mathrm{non}-\mathrm{ABS},& {\mathrm{RSRP}}_{\max }^{\mathrm{Marcro}}\&le;{\mathrm{RSRP}}_{\mathrm{serve}}^{\mathrm{Pico}}\end{array}\right.$

[rule 1]

User in its community is divided into CRE user (CRE-UE) and Microcell central user (Center-UE), and by CRE user scheduling on ABS, by the scheduling of Microcell central user on non-ABS.Wherein, for in the Microcell reporting of user data that base station receives from the Reference Signal Received Power that the interference of all macro base stations is the strongest, namely base station select that this Microcell user receives from the maximum in the RSRP of all macro base stations; for the Reference Signal Received Power from the micro-base station of current home in the Microcell reporting of user data that base station receives.

RSRP and RSRQ from current home macro base station that macrocell user reporting measurement obtains, macro cell base station selects 10 minimum macrocell user of RSRP, is designated as select 10 users that RSRQ is minimum, be designated as according to

[rule 2]

Select macrocell boundary user.In macrocell 1 and coverage thereof, the user distribution of Microcell is as shown in table 2

Table 2 user distribution result

Second step: if macrocell is selected in boundary user access the user that Microcell can obtain higher SINR when comparing access current home macrocell, and using the preselected Microcell of this Microcell as active user.Concrete steps are macro base station i (i ∈ Ω _macro) travel through its boundary user, judge whether active user k meets

${\mathrm{RSRP}}_k^{\mathrm{Pico},j}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Pico}},l\&NotEqual;j}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Pico},l}>{\mathrm{RSRP}}_k^{\mathrm{Marcro},i}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Macro}},l\&NotEqual;i}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Macro},l}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Pico}}}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Pico},l}$ [rule 3]

If meet, according to

${\mathrm{bias}}_k^{\mathrm{Pico},j}={\mathrm{RSRP}}_k^{\mathrm{Macro},i}-{\mathrm{RSRP}}_k^{\mathrm{Pico},j}+\mathrm{\&Delta;}$ [rule 4]

Calculate active user k to cut the community bias needed for preselected Microcell j.By this user and the community that calculates is biased is designated as and according to

$\begin{array}{c}{\mathrm{\&Omega;}}_{\mathrm{macro}->\mathrm{pico}}^{i->j}=\{({\mathrm{UE}}_l,{\mathrm{bias}}_l^{\mathrm{Pico},j}),({\mathrm{UE}}_m,{\mathrm{bias}}_m^{\mathrm{Pico},j}).......({\mathrm{UE}}_n,{\mathrm{bias}}_n^{\mathrm{Pico},j}).......({\mathrm{UE}}_q,{\mathrm{bias}}_q^{\mathrm{Pico},j}),{\mathrm{UE}}_r,{\mathrm{bias}}_r^{\mathrm{Pico},j}\}\\ s.t{\mathrm{bias}}_l^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_m^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_n^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_q^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_r^{\mathrm{Pico},j}\end{array}$

[rule 5]

Income set (i ∈ Ω _macro, j ∈ Λ _{macro, i}).Wherein, Λ _{macro, i}represent the micro-collection of base stations in macro base station i coverage, represent the RSRP that user k receives from macro base station i, represent the RSRP that user k receives from the micro-base station j in macro base station i coverage, ΔShi operator one of arranging according to network condition on the occasion of, object is that the new bias of guarantee makes user k handover success.

If Microcell is selected in CRE user access the user that macrocell can obtain the SINR higher than access current home Microcell, and using the preselected macrocell of this macrocell as active user.Concrete steps are micro-base station j (the j ∈ Λ in macro base station i coverage _{macro, i}) travel through its CRE user, judge whether active user k meets

${\mathrm{RSRP}}_k^{\mathrm{Pico},j}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Pico}},l\&NotEqual;j}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Pico},l}<{\mathrm{RSRP}}_k^{\mathrm{Macro},i}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Macro}},l\&NotEqual;i}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Macro},l}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Pico}}}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Pico},l}$

[rule 6]

If meet, according to

${\mathrm{bias}}_k^{\mathrm{Pico},j}={\mathrm{RSRP}}_k^{\mathrm{Macro},i}-{\mathrm{RSRP}}_k^{\mathrm{Pico},j}-\mathrm{\&Delta;}$ [rule 7]

Calculate active user k to cut the community bias needed for preselected macro base station.This user and respective cell are biased and are designated as and according to

$\begin{array}{c}{\mathrm{\&Omega;}}_{\mathrm{pico}->\mathrm{macro}}^{j->i}=\{({\mathrm{UE}}_l,{\mathrm{bias}}_l^{\mathrm{Pico},j}),({\mathrm{UE}}_m,{\mathrm{bias}}_m^{\mathrm{Pico},j}).......({\mathrm{UE}}_n,{\mathrm{bias}}_n^{\mathrm{Pico},j}).......({\mathrm{UE}}_q,{\mathrm{bias}}_q^{\mathrm{Pico},j}),{\mathrm{UE}}_r,{\mathrm{bias}}_r^{\mathrm{Pico},j}\}\\ s.t{\mathrm{bias}}_l^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_m^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_n^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_q^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_r^{\mathrm{Pico},j}\end{array}$

[rule 8]

Income set wherein, represent the RSRP that user k receives from micro-base station j, represent the RSRP that user k receives from macro base station i, ΔShi operator one of arranging according to network condition on the occasion of, object is that the new bias of guarantee makes user k handover success.

and data as shown in table 3:

Table 3 and data

3rd step: according to

${\mathrm{\&eta;}}_i^{\mathrm{macro}}=\frac{\underset{k\&Element;{\mathrm{\&Omega;}}_{\mathrm{macro}}^i}{\mathrm{\&Sigma;}}{N}_k^{\mathrm{macro}}}{N_{\mathrm{PRB}}^{\mathrm{macro}}}$ [rule 9]

Calculate macrocell i resources occupation rate.Wherein, for the user of macrocell i gathers; represent the resource block number needed for a kth user of current macro cell; represent the resource block number that current macro cell has.

According to

${\mathrm{\&eta;}}_j^{\mathrm{pico}}=\frac{\underset{k\&Element;{\mathrm{\&Omega;}}_{\mathrm{pico}}^j}{\mathrm{\&Sigma;}}{N}_k^{\mathrm{pico}}}{N_{\mathrm{PRB}}^{\mathrm{pico}}}$ [rule 10]

Calculate the resources occupation rate of Microcell j.Wherein, for the user of Microcell j in macrocell i gathers; represent the resource block number needed for a kth user of current micro cell; represent the resource block number that Microcell has.The control base station (Pico) of Microcell is by X2 interface, or by S1 interface, or by OAM (Operations,Administration And Maintenance center), or by the interface between base station and base station telegon, each for Microcell zone user resources occupation rate and throughput are sent to the control base station of macrocell.The resources occupation rate of the Microcell in macrocell 1 and coverage thereof is as shown in the table:

Table 4 resources occupation rate table

Macroi,Picoj	RE％
		Pico1	35％
Pico2	20％

Macroi	RE％
		Macro1	80％

According to

${\mathrm{\&omega;}}_{i,j}=\frac{{\mathrm{\&eta;}}_j^{\mathrm{pico}}}{{\mathrm{\&eta;}}_i^{\mathrm{macro}}}$ [rule 11]

Calculate the ratio ω of the resources occupation rate of Microcell j and the resources occupation rate of macrocell i in macrocell i _i,j.The resources occupation rate of macrocell 1 and Microcell in its coverage is than as shown in table 5

Table 5 is grand/Microcell resources occupation rate ratio

Macroi,Picoj	ω i,j
		Pico1	43.8％
Pico2	25％

As can be seen here, the load between the Microcell in macrocell 1 and its coverage is very unbalanced, needs to adjust community is biased.

4th step: if macrocell i and Microcell j load balancing, i.e. ω _i,j∈ [ω ₀, ω ₁], terminate the biased adjustment in community of Microcell j; If Macro cell load is heavier, i.e. ω _i,j< ω ₀, enter the 5th step; If Pico heavier loads, ω _i,j> ω ₁, enter the 6th step;

5th step: still untreated user is taken out successively according to the user's order in set, after judging that active user k switches Microcell j, whether required business demand can be met in ABS, namely judges that can Microcell j provide the Resource Block needed for active user k, if can meet, then bias is adjusted to the bias value of middle correspondence, user carries out reselecting of Serving cell according to the bias after adjustment and accesses, and returns the 3rd step.If can not meet, terminate the biased adjustment in community of Microcell j.

6th step: still untreated user is taken out successively according to the user's order in set, after judging that active user k switches Macro, whether required business demand can be met in Macro, namely judges that can macrocell i provide the Resource Block needed for active user k, if can meet, then bias is adjusted to the bias value of middle correspondence, user carries out reselecting of Serving cell according to the bias after adjustment and accesses, and returns the 3rd step.If can not meet, terminate the biased adjustment in community of Microcell j.

Be biased iteration through repeatedly community, meet ω _i,jafter ∈ [0.5,1.5], in macrocell 1 coverage, each Microcell bias is as shown in the table:

Table 6 community be biased iteration complete after bias table

Pico	Bias/dB
		Pico1	6
Pico2	9

User distribution result is as shown in table 7:

Table 7 user profile table

The resources occupation rate of macrocell 1 and Microcell in its coverage is than as shown in table 8

Table 8 is grand/Microcell resources occupation rate ratio

Macroi,Picoj	ω i,j
		Pico1	52％
Pico2	64％

Visible, the load between the Microcell in final macrocell 1 and its coverage reaches balanced.

The above-mentioned first step ~ the 6th step repeats according to cycle T=40ms.

Embodiment two

Construct a TD-LTE-Advanced HetNet network as shown in Figure 2, one has 7 macrocells, has 2 Microcells in each macrocell coverage area.The frequency duplex factor as one of minizone is 1.Each Physical Resource Block bandwidth is 180kHz, and the distance between adjacent macro cell is 500 meters.In this example, each macrocell is uniform-distribution with 40 users, and Cell Center User and cell edge area user are than for 1:3, and wherein user centered by No. 1-10, No. 11-40 is edge customer.It is 6dB that community is biased initial value.Other important parameters in system are as shown in table 9 below:

Table 9: the system parameters in embodiment two

It is a kind of for the biased method of adjustment of adaptive cell expansion in TD-LTE-A heterogeneous network that the embodiment of the present invention provides, and after initial cell is biased, the cycle performs following step:

The first step: the Reference Signal Received Power (RSRP from macro base station and the micro-base station of current home that Microcell all reporting of user measurement obtains, Reference Signal Receiving Power), after micro-base station receives and belongs to the measurement result of all users in this community, statistical average is done to RSRP, according to

$\mathrm{Pico}-\mathrm{UE}=\left\{\begin{array}{cc}\mathrm{CRE}-\mathrm{UE}\&LeftArrow;\mathrm{ABS},& {\mathrm{RSRP}}_{\mathrm{serve}}^{\mathrm{Pico}}<{\mathrm{RSRP}}_{\max }^{\mathrm{Macro}}\&le;{\mathrm{RSRP}}_{\mathrm{serve}}^{\mathrm{Pico}}+\mathrm{Bias}\\ \mathrm{Center}-\mathrm{UE}\&LeftArrow;\mathrm{non}-\mathrm{ABS},& {\mathrm{RSRP}}_{\max }^{\mathrm{Marcro}}\&le;{\mathrm{RSRP}}_{\mathrm{serve}}^{\mathrm{Pico}}\end{array}\right.$

[rule 1]

User in its community is divided into CRE user (CRE-UE) and Microcell central user (Center-UE), and by CRE user scheduling on ABS, by the scheduling of Microcell central user on non-ABS.Wherein, for in the Microcell reporting of user data that base station receives from the Reference Signal Received Power that the interference of all macro base stations is the strongest, namely base station select that this Microcell user receives from the maximum in the RSRP of all macro base stations; for the Reference Signal Received Power from the micro-base station of current home in the Microcell reporting of user data that base station receives.

RSRP and RSRQ from current home macro base station that macrocell user reporting measurement obtains, macro cell base station selects 10 minimum macrocell user of RSRP, is designated as select 10 users that RSRQ is minimum, be designated as according to

[rule 2]

Select macrocell boundary user.In macrocell 1 and coverage thereof, the user distribution of Microcell is as shown in table 10

Table 10 user distribution result

Second step: if macrocell is selected in boundary user access the user that Microcell can obtain higher SINR when comparing access current home macrocell, and using the preselected Microcell of this Microcell as active user.Concrete steps are macro base station i (i ∈ Ω _macro) travel through its boundary user, judge whether active user k meets

${\mathrm{RSRP}}_k^{\mathrm{Pico},j}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Pico}},l\&NotEqual;j}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Pico},l}>{\mathrm{RSRP}}_k^{\mathrm{Marcro},i}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Macro}},l\&NotEqual;i}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Macro},l}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Pico}}}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Pico},l}$ [rule 3] if meet, according to

${\mathrm{bias}}_k^{\mathrm{Pico},j}={\mathrm{RSRP}}_k^{\mathrm{Macro},i}-{\mathrm{RSRP}}_k^{\mathrm{Pico},j}+\mathrm{\&Delta;}$ [rule 4] calculates active user k to cut the community bias needed for preselected Microcell j.By this user and the community that calculates is biased is designated as and according to

$\begin{array}{c}{\mathrm{\&Omega;}}_{\mathrm{macro}->\mathrm{pico}}^{i->j}=\{({\mathrm{UE}}_l,{\mathrm{bias}}_l^{\mathrm{Pico},j}),({\mathrm{UE}}_m,{\mathrm{bias}}_m^{\mathrm{Pico},j}).......({\mathrm{UE}}_n,{\mathrm{bias}}_n^{\mathrm{Pico},j}).......({\mathrm{UE}}_q,{\mathrm{bias}}_q^{\mathrm{Pico},j}),{\mathrm{UE}}_r,{\mathrm{bias}}_r^{\mathrm{Pico},j}\}\\ s.t{\mathrm{bias}}_l^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_m^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_n^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_q^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_r^{\mathrm{Pico},j}\end{array}$

[rule 5]

Income set (i ∈ Ω _macro, j ∈ Λ _{macro, i}).Wherein, Λ _{macro, i}represent the micro-collection of base stations in macro base station i coverage, represent the RSRP that user k receives from macro base station i, represent the RSRP that user k receives from the micro-base station j in macro base station i coverage, ΔShi operator one of arranging according to network condition on the occasion of, object is that the new bias of guarantee makes user k handover success.

If Microcell is selected in CRE user access the user that macrocell can obtain the SINR higher than access current home Microcell, and using the preselected macrocell of this macrocell as active user.Concrete steps are micro-base station j (the j ∈ Λ in macro base station i coverage _{macro, i}) travel through its CRE user, judge whether active user k meets

${\mathrm{RSRP}}_k^{\mathrm{Pico},j}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Pico}},l\&NotEqual;j}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Pico},l}<{\mathrm{RSRP}}_k^{\mathrm{Macro},i}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Macro}},l\&NotEqual;i}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Macro},l}-\underset{l\&Element;{\mathrm{\&Omega;}}_{\mathrm{Pico}}}{\mathrm{\&Sigma;}}{\mathrm{RSRP}}_k^{\mathrm{Pico},l}$ [rule 6]

If meet, according to

${\mathrm{bias}}_k^{\mathrm{Pico},j}={\mathrm{RSRP}}_k^{\mathrm{Macro},i}-{\mathrm{RSRP}}_k^{\mathrm{Pico},j}-\mathrm{\&Delta;}$ [rule 7]

Calculate active user k to cut the community bias needed for preselected macro base station.This user and respective cell are biased and are designated as and according to

$\begin{array}{c}{\mathrm{\&Omega;}}_{\mathrm{pico}->\mathrm{macro}}^{j->i}=\{({\mathrm{UE}}_l,{\mathrm{bias}}_l^{\mathrm{Pico},j}),({\mathrm{UE}}_m,{\mathrm{bias}}_m^{\mathrm{Pico},j}).......({\mathrm{UE}}_n,{\mathrm{bias}}_n^{\mathrm{Pico},j}).......({\mathrm{UE}}_q,{\mathrm{bias}}_q^{\mathrm{Pico},j}),{\mathrm{UE}}_r,{\mathrm{bias}}_r^{\mathrm{Pico},j}\}\\ s.t{\mathrm{bias}}_l^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_m^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_n^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_q^{\mathrm{Pico},j}\&le;{\mathrm{bias}}_r^{\mathrm{Pico},j}\end{array}$

[rule 8]

Income set wherein, represent the RSRP that user k receives from micro-base station j, represent the RSRP that user k receives from macro base station i, ΔShi operator one of arranging according to network condition on the occasion of, object is that the new bias of guarantee makes user k handover success.

and data as shown in table 11:

Table 11 and data

3rd step: according to

${\mathrm{\&eta;}}_i^{\mathrm{macro}}=\frac{\underset{k\&Element;{\mathrm{\&Omega;}}_{\mathrm{macro}}^i}{\mathrm{\&Sigma;}}{N}_k^{\mathrm{macro}}}{N_{\mathrm{PRB}}^{\mathrm{macro}}}$ [rule 9]

Calculate macrocell i resources occupation rate.Wherein, for the user of macrocell i gathers; represent the resource block number needed for a kth user of current macro cell; represent the resource block number that current macro cell has.

According to

${\mathrm{\&eta;}}_i^{\mathrm{macro}}=\frac{\underset{k\&Element;{\mathrm{\&Omega;}}_{\mathrm{macro}}^i}{\mathrm{\&Sigma;}}{N}_k^{\mathrm{macro}}}{N_{\mathrm{PRB}}^{\mathrm{macro}}}$ [rule 10]

Calculate the resources occupation rate of Microcell j.Wherein, for the user of Microcell j in macrocell i gathers; represent the resource block number needed for a kth user of current micro cell; represent the resource block number that Microcell has.The resources occupation rate of the Microcell in macrocell 1 and coverage thereof is as shown in the table:

Table 12 resources occupation rate table

Picoj

RE％

Pico1	85％
		Pico2	80％

Macroi	RE％
		Macro1	20％

According to

${\mathrm{\&eta;}}_j^{\mathrm{pico}}=\frac{\underset{k\&Element;{\mathrm{\&Omega;}}_{\mathrm{pico}}^j}{\mathrm{\&Sigma;}}{N}_k^{\mathrm{pico}}}{N_{\mathrm{PRB}}^{\mathrm{pico}}}$ [rule 10]

Calculate the ratio ω of the resources occupation rate of Microcell j and the resources occupation rate of macrocell i in macrocell i _i,j.The resources occupation rate of macrocell 1 and Microcell in its coverage is than as shown in table 13:

Table 13 is grand/Microcell resources occupation rate ratio

Picoj	ω i,j
		Pico1	4.35
Pico2	4

As can be seen here, the load between the Microcell in macrocell 1 and its coverage is very unbalanced, needs to adjust community is biased.

4th step: if macrocell i and Microcell j load balancing, i.e. ω _i,j∈ [ω ₀, ω ₁], terminate the biased adjustment in community of Microcell j; If Macro cell load is heavier, i.e. ω _i,j< ω ₀, enter the 5th step; If Pico heavier loads, ω _i,j> ω ₁, enter the 6th step;

5th step: still untreated user is taken out successively according to the user's order in set, after judging that active user k switches Microcell j, whether required business demand can be met in ABS, namely judges that can Microcell j provide the Resource Block needed for active user k, if can meet, then bias is adjusted to the bias value of middle correspondence, user carries out reselecting of Serving cell according to the bias after adjustment and accesses, and returns the 3rd step.If can not meet, terminate the biased adjustment in community of Microcell j.

6th step: still untreated user is taken out successively according to the user's order in set, after judging that active user k switches Macro, whether required business demand can be met in Macro, namely judges that can macrocell i provide the Resource Block needed for active user k, if can meet, then bias is adjusted to the bias value of middle correspondence, user carries out reselecting of Serving cell according to the bias after adjustment and accesses, and returns the 3rd step.If can not meet, terminate the biased adjustment in community of Microcell j.

Be biased iteration through repeatedly community, meet ω _i,jafter ∈ [0.5,1.5], in macrocell 1 coverage, each Microcell bias is as shown in the table:

Table 14 community be biased iteration complete after bias table

Pico	Bias/dB
		Pico1	3
Pico2	3

User distribution result is as shown in Table 15:

Table 15 user profile table

The resources occupation rate of macrocell 1 and Microcell in its coverage is than shown in table 16

Table 16 is grand/Microcell resources occupation rate ratio

Picoj	ω i,j
		Pico1	61％
Pico2	73％

Visible, the load between the Microcell in final macrocell 1 and its coverage reaches balanced.

The above-mentioned steps first step ~ the 6th step repeats according to cycle T=40ms.

The above is only the preferred embodiment of the present invention; be noted that for those skilled in the art; under the premise without departing from the principles of the invention, can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (8)

1., for the biased method of adjustment of adaptive cell expansion in TD-LTE-A heterogeneous network, it is characterized in that, after initial cell is biased, the cycle performs following step:

The first step: the parameter that the signal receiving quality based on reporting of user is relevant, user in each Microcell is divided into spreading range region, Microcell (CRE) user and central user, and, the user in each macrocell is divided into macrocell boundary user and central user;

Second step: select the user that can cut Microcell j in it in the boundary user of macrocell i, and calculate corresponding community bias, by user and the set of corresponding bias composition in the CRE user of Microcell j, select the user that can cut macrocell i, and calculate corresponding community bias, by user and the set of corresponding bias composition wherein, i ∈ Ω _macro, j ∈ Λ _{macro, i}, Ω _macrofor macro base station set all in network, Λ _{macro, i}for the micro-collection of base stations in macro base station i coverage;

3rd step: the resources occupation rate calculating each macrocell and each Microcell, and the ratio ω calculating the resources occupation rate of Microcell j in macrocell i and the resources occupation rate of macrocell i _i,j;

4th step: according to ω _i,jthe community bias of value adjustment Microcell j, if ω _i,jwithin the scope preset, then terminate the biased adjustment in community of Microcell j; If ω _i,jbe less than default range lower limit, then enter the 5th step; If ω _i,jbe greater than default range limit, then enter the 6th step;

5th step: according to bias in set order from small to large takes out still untreated user successively, and after judging that active user k switches Microcell j, if required business demand can be met in community, then the biased of Microcell j is adjusted to the active user k of middle storage cuts the bias needed for the j of Microcell, and user carries out reselecting of Serving cell according to the bias after adjustment and accesses, and returns the 3rd step; If can not meet, terminate the biased adjustment in community of Microcell j;

6th step: according to bias in set order from small to large takes out still untreated user successively, and after judging that active user k switches macrocell, if required business demand can be met in macrocell, then the community of Microcell j is biased is adjusted to the active user k of middle storage cuts the bias needed for macrocell i, and user carries out reselecting of Serving cell according to the bias after adjustment and accesses, and returns the 3rd step, if can not meet, terminates the biased adjustment in community of Microcell j.

2. according to claim 1 a kind of for the biased method of adjustment of adaptive cell expansion in TD-LTE-A heterogeneous network, it is characterized in that, user in each Microcell is divided in the concrete steps of Microcell CRE user and central user in the described first step, comprises:

The Reference Signal Received Power (RSRP) from macro base station and the micro-base station of current home that Microcell all reporting of user measurement obtains;

Microcell base station after receiving the RSRP measurement result belonging to all users in this community, according to [rule 1]

Divide and dispatch the user in its community, by Microcell CRE user (CRE-UE) scheduling on ABS, by Microcell central user (Center-UE) scheduling on non-ABS; Wherein, for in the Microcell reporting of user data that base station receives from the Reference Signal Received Power that the interference of all macro base stations is the strongest, namely base station select that this Microcell user receives from the maximum in the RSRP of all macro base stations; for the Reference Signal Received Power from the micro-base station of current home in the Microcell reporting of user data that base station receives.

3. according to claim 1 a kind of for the biased method of adjustment of adaptive cell expansion in TD-LTE-A heterogeneous network, it is characterized in that, user in each macrocell is divided in the concrete steps of macrocell boundary user and central user in the described first step, comprises:

The RSRP from current home macro base station that all reporting of user measurements of macrocell obtain and Reference Signal Received Quality (RSRQ);

Macro cell base station, after receiving the RSRP measurement result belonging to all users in this community, is selected N number of macrocell user that RSRP is minimum, is designated as select N number of user that RSRQ is minimum, be designated as according to

Select macrocell boundary user, wherein, N is the positive integer arranged according to network condition.

4. according to claim 1 a kind of for the biased method of adjustment of adaptive cell expansion in TD-LTE-A heterogeneous network, it is characterized in that, in the boundary user of each macrocell, the user that can cut Microcell in it is selected in described second step, and calculate in the concrete steps of corresponding community bias, comprising:

Macro base station i travels through its boundary user, i ∈ Ω _macro, Ω _macrofor macro base station set all in network, according to

[rule 3]

If judge, active user k accesses Microcell j and whether can obtain the SINR higher than access current home macrocell i; If can, according to

[rule 4]

Calculate active user k to cut the community bias needed for this preselected Microcell j, by this user and the community that calculates is biased is designated as

According to

[rule 5]

Income set in, i ∈ Ω _macro, j ∈ Λ _{macro, i}, Λ _{macro, i}represent the micro-collection of base stations in macro base station i coverage, Ω _picofor micro-collection of base stations all in network, represent the RSRP that user k receives from macro base station i, represent the RSRP that user k receives from the micro-base station j in macro base station i coverage, Δ be of arranging according to network condition on the occasion of.

5. according to claim 1 a kind of for the biased method of adjustment of adaptive cell expansion in TD-LTE-A heterogeneous network, it is characterized in that, in the CRE user of each Microcell, the user that can cut macrocell is selected in described second step, and calculate in the concrete steps of corresponding community bias, comprising:

Micro-base station j in macro base station i coverage travels through its CRE user, i ∈ Ω _macro, j ∈ Λ _{macro, i}, Ω _macrofor macro base station set all in network, Λ _{macro, i}for the micro-collection of base stations in macro base station i coverage, according to

[rule 6]

If judge, active user k accesses macrocell i and whether can obtain the SINR higher than access current home Microcell j; If can, according to

[rule 7]

Calculating active user k to cut the community bias needed for preselected macrocell i, this user and respective cell being biased and being designated as

According to

[rule 8]

Income set wherein, represent the RSRP that user k receives from micro-base station j, represent the RSRP that user k receives from macro base station i, Δ be of arranging according to network condition on the occasion of.

6. a kind of biased method of adjustment of adaptive cell expansion in TD-LTE-A heterogeneous network according to claim 1, is characterized in that, calculate in described 4th step macrocell i resources occupation rate according to rule be:

[rule 9]

Wherein, for the user of macrocell i gathers; represent the resource block number needed for a kth user of current macro cell; represent the resource block number that current macro cell has.

Calculate Microcell j resources occupation rate according to rule be:

[rule 10]

Wherein, for the user of Microcell j in macrocell i gathers; represent the resource block number needed for a kth user of current micro cell; represent the resource block number that Microcell has.

7. according to claim 6 a kind of for the biased method of adjustment of adaptive cell expansion in TD-LTE-A heterogeneous network, it is characterized in that, calculating the resources occupation rate of Microcell j in macrocell i in described 4th step with the rule of the ratio of the resources occupation rate of macrocell i is:

[rule 11].

8. according to claim 1 a kind of for the biased method of adjustment of adaptive cell expansion in TD-LTE-A heterogeneous network, it is characterized in that, the described first step ~ the 6th step is according to cycle T=N*T _framerepeat, the biased adjustment of all micro-base stations synchronously performs; Wherein T _framerepresent the time of a TD-LTE complete radio frames, N is positive integer.