CN102394675B - Base station and methods for selecting service mode and feeding back pre-coding matrix - Google Patents

Abstract

The invention provides a base station and methods for selecting a service mode and feeding back a pre-coding matrix. The base station comprises a plurality of distributed nodes and a controller, wherein the distributed nodes are used for providing wireless access service for a terminal; and the controller is connected with the plurality of distributed nodes and used for selecting one or more distributed nodes from the plurality of distributed nodes as service nodes and controlling the service nodes to provide the wireless access service for the terminal. By the invention, the plurality of distributed nodes are adopted in the base station, so that an interval between antennae of the base station is increased, the coverage range of the base station is expanded, and an effect of improving the capacity of a wireless communication system is achieved.

Description

The feedback method of base station, service mode system of selection and pre-coding matrix

Technical field

The present invention relates to the communications field, in particular to a kind of base station and the service mode that is applied to this base station selects Feedback method with pre-coding matrix.

Background technology

With the development of mobile communication data business, the requirement more and more higher to wireless access system.And current channel radio The frequency range that letter system uses has higher and higher trend, the decay aggravation of radiofrequency signal, decreases the effective coverage range of base station, Especially in the case that densely populated place and terminal high-speed are mobile, how to increase power system capacity and covering, reduce terminal Switching times and cutting off rate, be communication system always endeavour solve a difficult problem.

Multiple-input and multiple-output (MIMO) technology (or multi-antenna technology) can reduce the frequency of wireless signal multipath transmisstion formation Rate Selective intensity, utilization space diversity gain, improves spectrum efficiency and the lift system capacity of base station.But present MIMO should With, all antennas of a base station all on same place, because, limited by the area of base station, antenna distance is less, thus have impact on The capacity of wireless communication system.

Content of the invention

Present invention is primarily targeted at providing a kind of base station system and the service mode selection being applied to this base station system Method, affects asking of capability of wireless communication system at least to solve less with antenna distance limited by the above-mentioned area due to base station Topic.

According to an aspect of the invention, it is provided a kind of base station, including：Multiple distributed nodes, for carrying for terminal For wirelessly access；Controller, is connected with multiple distributed nodes, for selecting one or many from multiple distributed nodes Individual distributed node is as service node, and controls service node to provide wirelessly access for terminal.

Preferably, described controller is described terminal specified services node according to channel information or user service grade.

Preferably, described service node uses orthogonal resource to provide wirelessly access for described terminal, wherein, described Resource at least includes following one kind：Time, frequency, coding and space.

According to a further aspect in the invention, there is provided a kind of service mode system of selection, it is applied to the base station being described above, Including：Terminal obtains the channel information of multiple distributed nodes of base station；Terminal is sent out to the controller of base station according to channel information Send the request of switching service mode；Controller switches to corresponding service mould according to the access way that base station is provided by request Formula.

Preferably, terminal obtains the channel information of multiple distributed nodes of base station, including：Terminal measures the multiple of base station The Signal to Interference plus Noise Ratio of distributed node.

Preferably, terminal sends switching service mode request according to channel information to the controller of base station, including：Terminal will Maximum Signal to Interference plus Noise Ratio in the Signal to Interference plus Noise Ratio of multiple distributed nodes that measurement obtains is compared with predetermined threshold；Terminal according to than Relatively result sends corresponding switching service mode request to the controller of base station.

Preferably, terminal sends corresponding switching service mode request according to comparative result to the controller of base station, including： When maximum Signal to Interference plus Noise Ratio is less than first threshold, terminal sends to controller and switches to many distributed nodes jointly to terminal transmission The service mode request of data；When maximum Signal to Interference plus Noise Ratio be more than or equal to first threshold and less than Second Threshold when, terminal to Controller sends the service mode request switching to the cooperation of many distributed nodes precoding；When maximum Signal to Interference plus Noise Ratio is more than or equal to During Second Threshold, terminal sends the request of switching current base station to controller.

Preferably, before terminal sends corresponding switching service mode request according to comparative result to the controller of base station, Also include：Terminal will participate in jointly sending the numbering of the distributed node of data to terminal or participates in the distributed of precoding cooperation The numbering of node sends to controller.

According to another aspect of the invention, there is provided a kind of service mode system of selection, it is applied to the base station being described above, Including：Terminal obtains the channel information of multiple distributed nodes of base station；Channel information is sent to the controller of base station by terminal； Controller according to channel information by the access way that base station is provided switch to corresponding service mode or carry out base station switching or Power Control is carried out to multiple distributed nodes.

Preferably, channel information at least includes one below：Signal intensity that multiple distributed nodes are launched, it is derived from base Interference signal intensity outside standing.

In accordance with a further aspect of the present invention, there is provided a kind of feedback method of pre-coding matrix, it is applied to be described above Base station, including：Terminal receives the intermediate pilot that the service node of base station sends；Terminal calculates precoding square according to intermediate pilot Battle array or code book index, and pre-coding matrix or code book index are fed back to base station.

Preferably, before terminal receives the intermediate pilot of service node transmission of base station, also include：The controller of base station will The transmitting antenna packet of service node, and assign weight to every group of antenna；Service node passes through transmitting antenna in the middle of terminal transmission Pilot tone.

Preferably, controller carries out transmitting antenna packet in the following manner：Geographical position, polarised direction or dependency.

Preferably, when described service node is multiple, the controller of described base station controls adjacent service node not The same moment sends described intermediate pilot, and the time-frequency location of described intermediate pilot is notified described terminal.

By the present invention, adopting multiple distributed nodes in a base station, thus increased the spacing of antenna for base station, expanding The coverage of base station, and then reach the effect improving capability of wireless communication system.

Brief description

Accompanying drawing described herein is used for providing a further understanding of the present invention, constitutes the part of the application, this Bright schematic description and description is used for explaining the present invention, does not constitute inappropriate limitation of the present invention.In the accompanying drawings：

Fig. 1 is the structural representation of according to embodiments of the present invention one spaced antenna base station；

Fig. 2 is that the resource of an ofdm system divides schematic diagram；

Fig. 3 is according to embodiments of the present invention two spaced antenna architecture of base station schematic diagram；

Fig. 4 is the flow chart of according to embodiments of the present invention three terminal selection service mode；

Fig. 5 is according to embodiments of the present invention six pilot transmission and precoding matrix feedback flow chart；

Fig. 6 is the aerial array schematic diagram of according to embodiments of the present invention six homogenous linear placement；

Fig. 7 is according to embodiments of the present invention six dual-polarized antenna array schematic diagram.

Specific embodiment

To describe the present invention in detail below with reference to accompanying drawing and in conjunction with the embodiments.It should be noted that not conflicting In the case of, the embodiment in the application and the feature in embodiment can be mutually combined.

Embodiment one

Fig. 1 is the structural representation of according to embodiments of the present invention one spaced antenna base station, as shown in figure 1, this base station Including：Multiple distributed node D210, D211, D220 and D230；One controller C210, a transceiver.

Wherein, each distributed node comprises at least one transmission antenna, and all distributed nodes directly or Connect and be connected with controller C210, and at least one distributed node and controller be not or not same place；Distributed node to Terminal (U210, U230) or another distributed node transceiving radio frequency signal；One or more distributed sections selected by controller Point is by transceiver (with controller in same place) to terminal transceiving data or to distributed node transceiving data.

In the present embodiment, as no illustrated, distributed node equal only one of which transmitting antenna.Terminal and distributed node Reception antenna can be more than one.It is the data exchange process of base station and terminal room below.

Controller C210 is by channel information (terminal feedback or obtained using channel reciprocity) or user service etc. Level is the distributed node of user terminal specified services, and shown in Fig. 1, distributed node D210 passes through wireless channel L211 and terminal U210 connects, and U210 measures the channel quality of each distributed node, to controller reporting.When U210 moves to another location, L211 channel quality deteriorates, and controller, according to the feedback information receiving, assigns node D211 (to be furnished with one or more by signaling Reception antenna) service for U210, but the restriction due to current conditions, D211 and controller (such as can not be existed by wired connection In dense city, D211 and controller are respectively at the both sides in street, and U210 gets in), therefore data is passed through no by D210 Line channel R211 is sent to D211, then reaches U210 by D211 by wireless channel L212.

If the data traffic in D211 service area is big, one or more of following methods of the D211 that is combined as is provided to pass Transmission of data：

1) controller can assign multiple distributed nodes is D211 transmission data, the D220 in such as Fig. 1, then D210, D220 (transmission) and D211 (receiving, be furnished with multiple reception antennas) one mimo transmission system of composition, and provided using identical Source is scheduling to D211 service；

2) if for interference or other considerations, D210 and D220 uses orthogonal resource to service for D211, so-called orthogonal Even if being serviced for D211 with one or more of time-division, frequency division, code division, space division multiplexing technology；If D211 only one of which receives Antenna, using STBC (Space-Time Block Coding, space-time block code) or SFBC (Space-Frequency Block Coding, space-frequency block codes).Resource said herein includes one of time, frequency, coding, space or several combinations, than As the combination of time and frequency, specific to actual OFDMA (orthogonal frequency-division multiple Access, orthogonal frequency-time multiple access) communication system is it is simply that distribute to time slot (or symbol) and the subcarrier of user, as Fig. 2 institute Show, each lattice represent a running time-frequency resource, can be represented with two-dimensional coordinate (subcarrier, symbol), subcarrier represents frequency dimension, Symbology time dimension.

Wherein, if D211 is replaced with a user terminal, said method is equally applicable.

If in base station in some nodes transmitting-receiving data less (referred to as low-load node), and adjacent node is detected and have Available resource, controller sends signaling makes the user in these nodes be switched to adjacent node, and low-load node does not retransmit Data, to reduce system power dissipation and interference.

By the present embodiment, adopting multiple distributed nodes in a base station, thus increased the spacing of antenna for base station, expanding The coverage of base station, and then reach the effect improving capability of wireless communication system.

Embodiment two

Fig. 3 is according to embodiments of the present invention two spaced antenna architecture of base station schematic diagram, as shown in figure 3, this is distributed Base station includes：Multiple distributed nodes (D210, D220, D230), controller C210, transceiver.It is eventually by distributed node End (U210, U220, U230) provides wirelessly access.

Wherein, the present embodiment and the difference implementing are, the base station of the present embodiment only has one-level distributed node, i.e. institute The formula node of being distributed all is directly connected to controller.The data exchange process of the present embodiment base station and terminal room and embodiment one phase With no further details to be given herein.

To describe in detail in the base station architecture in embodiment two with embodiment three and example IV below, terminal and base station Cooperation carries out the switching of service mode or the switching of base station.

Embodiment three

Fig. 4 is the flow chart of according to embodiments of the present invention three terminal selection service mode；The present embodiment uses embodiment Base station system in two, wherein, each distributed node configures multiple transmitting antennas, and only has one-level distributed node.This Embodiment relates generally to user's switching between different nodes in same base station in distributing antenna system.

Wherein, in the present embodiment, be multiple distributed nodes of same subscriber transceiving data set, referred to as one association Make cluster, in a base station, there may be multiple cooperative cluster.In following methods, all of measured value can be that statistical value can also be Immediately measured value, is specifically determined by terminal.

Node serve pattern in the present embodiment includes：Terminal is serviced by multiple distributed nodes, and terminal is by a node Service.The switching of service mode is not related to the switching of controller (or base station), and that is, terminal is still using original base station controller.

The present embodiment describes the channel information that terminal measures each distributed node in detail, initiates node clothes after being calculated Business pattern switching or the process of controller handover request, as shown in figure 4, comprise the following steps：

Step S402, calculates the SINR of each node.

It is located at certain moment t1, U210 provides access service by node D210.The Signal to Interference plus Noise Ratio value of terminal U210 is SINR； Signal (power) intensity that U210 receives D210 transmitting is RSSI；The interference recording outside base station in moment t2 is INT1；When The signal intensity carving remaining node that t3 records in base station in addition to the maximum node of N number of signal intensity is INT0, and wherein N is by C210 It is broadcast to the terminal in base station, or can be obtained by terminal in the following manner：

N=| and i | RSSI (i)-RSSI_th＞ RSSI_hy}|

Wherein, RSSI_th、RSSI_hyIt is broadcast to the terminal in base station by C210, above formula asks received signal strength to be more than threshold The node number of value, N can also be determined by terminal additive method；There is no necessary connection between t1, t2, t3；U210 surveys simultaneously The signal intensity of adjacent node in amount base station, and obtain RSSI (i) by descending arrangement, letter under adjacent node for the terminal is done Make an uproar and than in certain moment be：

$\mathrm{SINR}\left(i\right)=\frac{\mathrm{RSSI}}{\underset{k\∈D_A,k\≠i}{\mathrm{\Σ}}\mathrm{RSSI}\left(k\right)+\mathrm{INT}0+\mathrm{INT}1+\mathrm{\σ}}$

The then maximum node of the corresponding U210 Signal to Interference plus Noise Ratio of SINR (1).SINRc is the Signal to Interference plus Noise Ratio of node cooperation transmission access Threshold value, SINRp is the access threshold value of cooperation precoding.

Step S404 compares SINR (1) and SINRc, if SINR (1) ＜ SINRc, U210 sends more piece to controller C210 Point is common to send request of data CO_REQ it is desirable to current controller and/or neighbouring controller increase node for it and send number for it According to, and the node serial number of participation is sent to current controller；Otherwise, execution step S406.

Step S406, compares SINR (1) and SINRp, if SINRc≤SINR (1) ＜ SINRp, U210 is to current controller C210 sends multiple spot precoding cooperation request CP_REQ, and the node of participation is sent to controller, and the node participating in cooperation can In same base station it is also possible to not in same base station；If SINR (1) >=SINRp, execution step S408.

Step S408, under SINR (1) >=SINRp, compares SINR (1) and SINR.If SINR (1)=SINR, U210 is still Only serviced by original node D210, separately do not deal with；Otherwise, execution step S410.

Step S410, if SINR (1)-SINR is ＞ SINRh, sending node handover request HO_REQ, request is switched to SINR (1) corresponding node, otherwise U210 still only serviced by original node D210, separately do not deal with.

Example IV

In the present embodiment, measured the channel information of each node by terminal, feed back to base station, determine to carry out mould by base station Formula switching, base station switching, or carry out distributed node power control.The following is the specific descriptions that the present embodiment executes flow process.

, equally using the base station system in embodiment two, the signal (power) that U210 receives D210 transmitting is strong for the present embodiment Spend for RSSI (0)；U210 measures the signal intensity of adjacent node in base station simultaneously, if the signal of front i maximum intensity is RSSI (i), i=1,2 ... ..., N, wherein N are broadcast to the terminal in base station by C210, or can be obtained by terminal in the following manner：

N=| and i | RSSI (i)-RSSI_th＞ RSSI_hy}|

Wherein, RSSI_th、RSSI_hyIt is broadcast to the terminal in base station by C210, above formula asks received signal strength to be more than threshold The node number of value, N can also be determined by terminal additive method.Meet the node set of above-mentioned condition, referred to as one activation Cluster, the node in activation cluster can not be updated in the same time.If system uses time division duplex, RSSI can be by each Node records.The interference recording outside base station in moment t2 is INT1；Record in moment t3 and in base station, remove N number of signal intensity maximum The signal intensity of remaining node outside node is INT0；There is no necessary connection between t1, t2, t3；RSSI (i) can be with direct feedback Numerical value (dBm), or adopt following form：

${\mathrm{RSSI}\left(i\right)}_{\mathrm{dB}}=10\log \frac{\mathrm{RSSI}\left(i\right)}{\mathrm{RSS}{I}_{\mathrm{th}}}$

Wherein i=0,1,2 ... N.INT0, INT1 are also according to above formula and RSSI_thAfter try to achieve dB value.

Received signal strength RSSI data and interference signal intensity INT1, INT0 are sent to controller C210 by terminal, send out Sending can be that terminal periodically sends or sent by C210 requesting terminal.Controller C210, according to the data receiving, judges U210 Whether want switching node service mode to be also by base station switching, or carry out power control, and send related signaling.

In systems in practice, due to the restriction of physical channel and terminal antenna number, when the antenna participating in transmitting increases, The availability of frequency spectrum of system can be affected, counteract the gain that antenna diversity brings, increased answering of system especially terminal simultaneously Miscellaneous degree.The following examples five, six, seven and eight each provide pilot transmission under different operating mode and pre-coding matrix is anti- Feedback method, to solve the above problems, wherein, the base station system structure being adopted refers to Fig. 3.

Embodiment five

In the present embodiment, further relate to the feedback of pre-coding matrix (or code book index), base station needs by signaling Terminal select corresponding pilot frequency system calculate pre-coding matrix (or pre-coding matrix numbering in precoding matrix codebook) and The related parameter of other channels.

If MIMO wireless channel coefficient matrix is H, its order is j；The signal x sending is k dimensional vector, in order to preferably utilize Channel information and solve the problems, such as that receiving terminal cannot reduce sending signal in the case of k ＞ j, introduces precoding in mimo system Technology, before precoding, the signal of receiving terminal is：Y=Hx, wherein y are receipt signal；After precoding, receipt signal is expressed as：Y= HPx, wherein P are pre-coding matrix.

If the maximum antenna number that in MIMO-OFDM system, single distribution node is supported is M_t, the maximum antenna that terminal is supported Number is N_r, N_MAXFor M_t、N_rHigher value in both, N_coFor participating in distributed node all transmitting antennas sum of cooperation transmission, The interference threshold RSSI0 that adjacent node causes, the frequency resource groups of cooperation are R, and the same frequency resource in R can be one Or multiple terminal service；It is R ' by the frequency resource groups that individual node provides service.For calculating the pilot tone of pre-coding matrix (or claiming reference signal), referred to as intermediate pilot, but the effect of intermediate pilot is not limited only to calculate pre-coding matrix.

As Fig. 3, D210 and D220 services for terminal U210 simultaneously, for reducing interference and pilot pattern reuses examines Consider, D210 and D220 is continuing with original intermediate pilot, but separately send in time, such as in different symbols or son On frame send (real system, such as LTE, WiMax), be located at moment t1 record D210 to U210 channel be H₁, it is calculated Corresponding pre-coding matrix is P₁, the channel recording D220 to U210 in moment t2 (t2 >=t1) is H₂, it is calculated corresponding pre- Encoder matrix is P₂, P₁, P₂Feed back to C110, at moment t3 (t3 ＞ t2, t3 ＞ t1), C110 uses P₁, P₂Send data, The signal that U210 receives is：Y=H₁P₁x+H₂P₂x.It is multiple use in same asset that the method is also applied for a cooperative cluster The situation of family service.

Embodiment five

If the signal sending is x, the signal y of receiving terminal, sent using following precoding mode：Y=HPx, wherein, P is Pre-coding matrix, H=[H₁, H₂], and in two kinds of situation：If the distributed node participating in cooperation sends pilot tone, using new simultaneously Pilot pattern, for example, D210 and D220 respectively has four transmitting antennas, and U210 has two reception antennas, then D210, D220 and U210 forms the MIMO antenna system using codebook of 8 × 2, and the pilot tone of transmission is 8 antenna pilot patterns in real system.

Embodiment six

When multi-node collaboration sends data to terminal, if the physical antenna number participating in cooperation exceedes individual node The antenna number that multipotency is supported, it is possible to use the pilot transmission described by the present embodiment and precoding matrix feedback method.As Fig. 5 Shown, including：

Step S502, is divided into several antenna sets all antennas participating in cooperation.If D210, D220 respectively have 8 to send out Penetrate antenna, jointly for U210 service, U210 has two reception antennas, the numbering of D210 is 1 to 8, with descending in principle according to this Antenna 1～8 is divided into 4 groups by one or more：

1) neighbouring antenna partition is one group, and in such as Fig. 6, all antennas are distributed point-blank, are divided into [1,2], [3,4], [5,6], [7,8] (so numbering is only for example, similarly hereinafter herein)

2) in configuration extremely in the case of doubleization antenna, the antenna partition in equipolarization direction for two groups { 1,3,5,7 } and 2, 4,6,8 }, such as in Fig. 7 (inclination angle of in figure is the direction of an electric field of antenna polarization ripple, is not the modes of emplacement of actual antennas), then It is divided into [1,3], [2,4], [5,7], four groups of [6,8].

3) correlation matrix of the transmitting terminal antenna according to terminal feedback divides, and what dependency was high is divided into one group, every group Two antennas.

The antenna of D220 can be divided into 4 groups of antennas, every group of 2 antennas in the same manner.The packet of antenna is not limited to said method, Antenna in same group may belong to different nodes, as long as the number of group internal antenna is identical.Two nodes have 8 antennas Two antennas of group, this 8 antenna sets and U210 form the MIMO antenna system using codebook of equivalent 8 × 2, if its equivalent letter Road transmission matrix is H_eq, two nodes collaborative transmission intermediate pilots, the 8 antenna pilot samples that pilot pattern is used by single node Formula.

Step S504, assigns weight to every group of antenna, and the antenna in same group sends identical data.For example：In Fig. 6, [1, 2] corresponding weight is vectorial W₁=[w_1,1, w_1,2], wherein w_{I, j}In i represent i-th group of antenna, j is antenna in antenna sets Numbering.

Step S506, terminal U210 records H_eq, calculate pre-coding matrix P, if system is using the code book collection quantifying, in code This concentration finds most suitable code book, and its index concentrated in code book is fed back to node D210 or D220.

Embodiment seven

In the present embodiment, controller carries out the transmitting of intermediate pilot according to following criterion.May be simultaneously in one base station There is cooperative cluster and precoding cluster.

When there is cooperative cluster in system, if N_co＞ N_MAX, using the method shown in embodiment 6 in the range of R, in R ' scope Interior using original pilot pattern；If N_co≤N_MAX, using the method shown in embodiment 5 in the range of R, using former in the range of R ' The pilot pattern come.Controller selects a node in cluster, as long as sending intermediate pilot, all sends out in whole frequency resources Send intermediate pilot；Other nodes in cluster, if synchronized transmission intermediate pilot, all send middle leading in whole frequency resources Frequently, otherwise only send original pilot pattern in the range of R '.If also there is precoding cluster in system, controller execution is non-same Step operation：Make adjacent node send pilot tone in the moment staggered, to avoid collision, and the time-frequency location of pilot tone is notified eventually End.

By the various embodiments described above of the present invention, there is provided a kind of distributed base station of use multi-antenna technology, meanwhile, also Provide a kind of mode switching method of service node and under different operating mode the transmitting of pilot tone and pre-coding matrix Feedback method.By adopting multiple distributed nodes in a base station, thus increased the spacing of antenna for base station, expand base station Coverage, and then reach lifting capability of wireless communication system, the effect of minimizing cutting off rate.

Obviously, those skilled in the art should be understood that each module of the above-mentioned present invention or each step can be with general Computing device realizing, they can concentrate on single computing device, or be distributed in multiple computing devices and formed Network on, alternatively, they can be realized with the executable program code of computing device, it is thus possible to they are stored To be executed by computing device in the storage device, and in some cases, can be with different from shown in order execution herein The step going out or describing, or they are fabricated to respectively each integrated circuit modules, or by the multiple modules in them or Step is fabricated to single integrated circuit module to realize.So, the present invention is not restricted to any specific hardware and software combination.

The foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, for the skill of this area For art personnel, the present invention can have various modifications and variations.All within the spirit and principles in the present invention, made any repair Change, equivalent, improvement etc., should be included within the scope of the present invention.

Claims (12)

1. a kind of base station is it is characterised in that include：

Multiple distributed nodes, for providing wirelessly access for terminal；

Controller, is connected with the plurality of distributed node, one or more for selecting from the plurality of distributed node Distributed node is as service node, and controls described service node to provide wirelessly access for described terminal；

Wherein, described controller is additionally operable to receive the switching service mode request that described terminal sends, wherein, described switching service Maximum Signal to Interference plus Noise Ratio in the Signal to Interference plus Noise Ratio of the plurality of distributed node that mode request is obtained according to measurement with described terminal Comparative result compared with predetermined threshold is corresponding.

2. base station according to claim 1 is it is characterised in that described controller is according to channel information or user service grade For described terminal specified services node.

3. base station according to claim 1 is it is characterised in that it is described terminal that described service node uses orthogonal resource There is provided wirelessly access, wherein, described resource at least includes following one kind：

Time, frequency, coding and space.

4. a kind of service mode system of selection, is applied to the base station described in any one of claims 1 to 3 it is characterised in that wrapping Include：

Terminal obtains the channel information of multiple distributed nodes of described base station；

Terminal sends the request of switching service mode according to described channel information to the controller of described base station；

Described controller switches to corresponding service mode according to the access way that described base station is provided by described request；

Wherein, when the Signal to Interference plus Noise Ratio that the channel information that terminal obtains is the plurality of distributed node, terminal is according to described letter Road information sends switching service mode request to the controller of described base station and includes：Described terminal by measure obtain the plurality of Maximum Signal to Interference plus Noise Ratio in the Signal to Interference plus Noise Ratio of distributed node is compared with predetermined threshold；Described terminal is according to described comparative result Send corresponding switching service mode request to the controller of described base station.

5. method according to claim 4 it is characterised in that described terminal according to described comparative result to described base station Controller sends corresponding switching service mode request, including：

When described maximum Signal to Interference plus Noise Ratio is less than first threshold, described terminal sends to described controller and switches to how distributed section Point sends the service mode request of data jointly to described terminal；

When described maximum Signal to Interference plus Noise Ratio is more than or equal to first threshold and is less than Second Threshold, described terminal is to described control Device sends the service mode request switching to the cooperation of many distributed nodes precoding；

When described maximum Signal to Interference plus Noise Ratio is more than or equal to Second Threshold, described terminal sends to described controller and switches current base The request stood.

6. method according to claim 5 it is characterised in that described terminal according to described comparative result to described base station Before controller sends corresponding switching service mode request, also include：

Described terminal will participate in jointly sending the numbering of the distributed node of data to described terminal or participates in precoding cooperation The numbering of distributed node sends to described controller.

7. a kind of service mode system of selection, is applied to the base station described in any one of claims 1 to 3 it is characterised in that wrapping Include：

Terminal obtains the channel information of multiple distributed nodes of described base station；

Described channel information is sent to the controller of described base station by described terminal；

The access way that described base station is provided is switched to corresponding service mode according to described channel information by described controller Or carry out base station switching or Power Control is carried out to the plurality of distributed node.

8. method according to claim 7 is it is characterised in that described channel information at least includes one below：Described many Signal intensity that individual distributed node is launched, the interference signal intensity outside described base station.

9. a kind of feedback method of pre-coding matrix, be applied to base station described in any one of claims 1 to 3 it is characterised in that Including：

Terminal receives the intermediate pilot that the service node of described base station sends；

Described terminal calculates pre-coding matrix or code book index according to described intermediate pilot, and by described pre-coding matrix or code This index feeds back to described base station.

10. method according to claim 9 is it is characterised in that terminal receives in the service node transmission of described base station Between also include before pilot tone：

The transmitting antenna of described service node is grouped by the controller of described base station, and assigns weight to every group of antenna；

Described service node sends described intermediate pilot by described transmitting antenna to described terminal.

11. methods according to claim 10 are it is characterised in that described controller carries out described transmitting sky in the following manner Line is grouped：Geographical position, polarised direction or dependency.

12. methods according to claim 9 it is characterised in that when described service node be multiple when, the control of described base station Device processed controls adjacent service node to send described intermediate pilot in the different moment, and the time-frequency location by described intermediate pilot Notify described terminal.