CN104935363A - Method and equipment for coordinated transmission - Google Patents

Abstract

The invention relates to a method and equipment for coordinated transmission. The method comprises the following steps: supporting coordinated transmission between one or more network control elements and a terminal on a resource element, for the coordinated transmission, forming a cooperative zone by a plurality of cells controlled by one or more network control elements, and only limiting the coordinated transmission on the resource element to not transmit a reference signal or the cells of a control channel symbol on the resource element when another cell of the cooperative zone is used for transmitting the reference or the control channel symbol on the resource element.

Description

For the method and apparatus of cooperation transmission

The divisional application that the application is application number is 200980160924.5, the applying date is 2009-8-14, denomination of invention is the application for a patent for invention of " improvement to cooperative multipoint transmission ".

Technical field

The present invention relates to a kind of equipment, method and computer program product, it relates to and transmits (particularly, coordinate multipoint (CoMP) is transmitted) relevant improvement about the cooperation (coordinated) of multiple network element (network element) and/or terminal.

Background technology

The following implication of the abbreviation used in this specification is suitable for:

A & F: amplify and forward

AP: antenna port

BER: bit error rate (bit error rate)

BS: base station

CAS: Cooperative District

CCE: control channel unit

CDF: cumulative distribution function

C-MIMO: cooperation multiple-input and multiple-output (cooperative multi input multi output)

CoMP: coordinate multipoint

COOPA: cooperation antenna

CQI: CQI

CRS: public reference signal

CSI: channel condition information

D & F: decoding and forwarding

DL: down link

ENB: enode b (eNodeB)

FDD: Frequency Division Duplexing (FDD)

GI: protection interval

HARQ: hybrid automatic repeat-request

LOS: sight line

MS: travelling carriage

MCS: modulation and encoding scheme

MIMO: multiple-input and multiple-output

MU-MIMO: multiuser MIMO

NB：NodeB

OFDM: OFDM

OFDMA: OFDM

PDCCH: physical downlink control channel

PDRS: precoding DRS (Dedicated Reference Signal) (precoded dedicated reference signal)

PDSCH: physical down link sharing channel

PRB: Physical Resource Block

R8: released version 8

RB: Resource Block

RE: Resource Unit

RNTI: Radio Physics temporary identifier

RS: reference signal

RRM: provided for radio resources management

RS: reference signal

SC: subcarrier

SDM: space division multiplexing

SINR: signal and noise interference

TDM: time division multiplexing

TDD: time division duplex

UE: subscriber equipment

ZF: ZF (zero forcing).

The application particularly relates to but is not limited to channel estimating.When the UE of fast moving, owing to becoming and frequency selectivity during radio channel larger, the channel estimating for broadband mobile radio system is generally a challenge.When being intended to carry out cooperation antenna (COOPA) system of relevant precoding to the data-signal from difference transmission website, because the radio channel of higher number and channel condition information (CSI) estimate relevant, required high accuracy, make this challenge even higher.

Recently, 3GPP is to so-called advanced LTE(LTE Advanced) research project technology investigates significantly to strengthen the property, and therefore, so-called cooperation or cooperative multipoint transmission (CoMP) have been identified as one of major technique improving spectrum efficiency.Identified different CoMP technology, wherein, the data of precoding are transferred to multiple UE from different eNB by more powerful CoMP technology in same time frequency resource simultaneously.Relevant precoding (add complexity and while causing a considerable amount of expenses relevant with channel estimating, feedback and backhaul traffic) be hopeful to obtain significant performance gain, this is because it allows optimum interference eliminate (interference cancellation) and have intrinsic diversity gain.In theory, the larger gain of approximately some 100% has been doped.

Because advanced LTE is regarded as the evolution from LTE released version 8, the therefore complete back compatible of General Requirements.

But this present especially relevant to CoMP problem, this is that technology owing to using for CoMP partly contradicts with current those technology used in such as LTE released version 8.

In addition, occur and dissimilar reference signal (such as channel condition information (CSI) reference signal (RS), precoding DRS (Dedicated Reference Signal) (pDRS, also demodulated reference signal DM-RS is referred to as) and public reference signal (CRS)) relevant problem, larger expense may be produced, which compromises the improvement realized by CoMP.

In addition, during the problems referred to above also may appear at except CoMP other cooperation transmission technology in (such as, appearing at MU-MIMO(multi-user's multiple-input and multiple-output) etc.).

Summary of the invention

Therefore, the object of the invention is to overcome above-mentioned prior art problem.

According to first aspect, the cooperation transmission between network control unit and terminal on Resource Unit is controlled.Detect Resource Unit and whether comprise discrete cell, and, when detecting that Resource Unit does not comprise discrete cell, select the Resource Unit being used for described cooperation transmission.Particularly, the invention provides a kind of method for cooperation transmission, comprise: support one or more network control unit and the transmission cooperated on Resource Unit between terminal, wherein for cooperation transmission, the multiple communities controlled by described one or more network control unit form Cooperative District, and when another community of described Cooperative District is on Resource Unit when transmission of reference signals or control channel symbol, described cooperation transmission on described Resource Unit is only limited in those communities of not transmitting described reference signal or described control channel symbol on described Resource Unit.Preferably, described method also comprises: eliminate the interference caused by the transmission in a resource unit of described reference signal.Described elimination in the terminal or in network element by deducting known disturbances or being performed by application precompensation in central network control unit.Described restriction comprises: when discrete cell is transmitted in another community on described Resource Unit, only those communities of not transmitting described discrete cell in described Resource Unit is applied to the described cooperation transmission in described Resource Unit.Described method also comprises the number detecting in the cell and be assigned to the control channel symbol of specific sub-frame.Described number detects by referring to control format designator.The transfer point of the predetermined number for described cooperation transmission on scheduled resource unit, when the described method number be also included in for the transfer point of described cooperation transmission is less than predetermined number, apply the precompensation of transmission and/or the intertexture to transmission, and/or apply different modulating and the encoding scheme of every symbol in the transmission.Use for the shared channel for transmitting data not comprising the Resource Unit used in the subframe of control channel symbol.Described Resource Unit forms OFDM symbol, and described control channel is physical downlink control channel, and described shared channel is physical down link sharing channel.Described cooperation transmission is multipoint cooperative (CoMP) transmission or multi-user's multiple-input and multiple-output (MU-MIMO) transmission.

Described discrete cell can be reference signal (such as CRS(public reference signal)) or for control channel symbol (the such as PDCCH(physical downlink control channel) symbol of control channel).The present invention is also by the another kind of method being used for cooperation transmission, comprise: on the Resource Unit cooperated by one or more network control unit, receive transmission in one cell, wherein for cooperation transmission, the multiple communities controlled by described one or more network control unit form Cooperative District, and wherein, when another community of described Cooperative District is on Resource Unit when transmission of reference signals or the control channel symbol for control channel, described cooperation transmission on described Resource Unit is only limited in those communities of not transmitting described reference signal or described control channel symbol on described Resource Unit, and eliminate or alleviate by described reference signal or the interference that causes for the transmission of the described control channel symbol of control channel.

According on the other hand, the transmission of reference signal is controlled in the Resource Unit of Resource Block in the cooperation transmission between network control unit and terminal.For the sequence of reference signal, use single (single) reference signal for all terminals, and, for each terminal, spatial pre-coding is carried out to single reference signal.

Reference signal can be pDRS(precoding DRS (Dedicated Reference Signal)).According to a kind of equipment for cooperation transmission of the present invention, comprise: transmission control unit (TCU), be configured to support one or more network control unit and the transmission cooperated on Resource Unit between terminal, wherein for cooperation transmission, the multiple communities controlled by described one or more network control unit form Cooperative District; And selector, be configured to when the described cooperation transmission on described Resource Unit when transmission of reference signals or control channel symbol, is only limited in those communities of not transmitting described reference signal or described control channel symbol on described Resource Unit by another community of described Cooperative District on Resource Unit.Preferably, described equipment also comprises: eliminate unit, is configured to eliminate the interference caused by reference signal transmission in a resource unit.Described equipment is configured to perform described elimination by application precompensation.Described detector is configured to detect in the cell the number of the control channel symbol being assigned to specific sub-frame.Described detector is configured to by referring to control format designator to detect described number.The transfer point of the predetermined number for described cooperation transmission on scheduled resource unit, wherein, described controller is also configured to when the number of the transfer point for described cooperation transmission is less than predetermined number, application to the precompensation of described transfer point and/or the intertexture to described transfer point, and/or applies different modulating and the encoding scheme of every symbol in described transfer point.Use for the shared channel for transmitting data not comprising the Resource Unit used in the subframe of control channel symbol.Described Resource Unit forms OFDM symbol, and described control channel is physical downlink control channel, and described shared channel is physical down link sharing channel.Described cooperation transmission is multipoint cooperative (CoMP) transmission or multi-user's multiple-input and multiple-output (MU-MIMO) transmission.The equipment of cooperation transmission is used for according to another kind, comprise: receiver, be configured on the Resource Unit cooperated by one or more network control unit, receive transmission in one cell, wherein for cooperation transmission, the multiple communities controlled by described network control unit form Cooperative District, and wherein, when another community of described Cooperative District is on Resource Unit when transmission of reference signals or the control channel symbol for control channel, described cooperation transmission on described Resource Unit is only limited in those communities of not transmitting described reference signal or described control channel symbol on described Resource Unit, and controller, be configured to eliminate or alleviate by described reference signal or the interference that causes for the transmission of the described control channel symbol of control channel.According to another equipment for cooperation transmission, comprise: for supporting the device of one or more network control unit and the transmission cooperated on Resource Unit between terminal, wherein for cooperation transmission, the multiple communities controlled by described one or more network control unit form Cooperative District; And on Resource Unit, when transmission of reference signals or control channel symbol, the described cooperation transmission on described Resource Unit is only limited in the device of those communities of not transmitting described reference signal or described control channel symbol on described Resource Unit for another community when described Cooperative District.According to another equipment for cooperation transmission, comprise: be provided on the Resource Unit cooperated by one or more network control unit, receive the device of transmission in one cell, wherein for cooperation transmission, the multiple communities controlled by described one or more network control unit form Cooperative District, and wherein, when another community of described Cooperative District is on Resource Unit when transmission of reference signals or the control channel symbol for control channel, described cooperation transmission on described Resource Unit is only limited in those communities of not transmitting described reference signal or described control channel symbol on described Resource Unit, and for eliminating or alleviating by described reference signal or the device of interference that causes for the transmission of the described control channel symbol of control channel.

According on the other hand, orthogonal precoding DRS (Dedicated Reference Signal) is sent to terminal from network element.Described terminal uses described precoding DRS (Dedicated Reference Signal) to estimate channel estimation results, and described network element receives described channel estimation results from described terminal.Based on the channel estimation results received, described network element determination channel information.

Above-mentioned cooperation transmission can be multipoint cooperative (CoMP) transmission or multi-user's multiple-input and multiple-output (MU-MIMO) transmission etc.

Accompanying drawing explanation

These and other objects, feature, details and advantage will become more apparent from the of the present invention following DETAILS SECTIONExample understood by reference to the accompanying drawings, in the accompanying drawings:

Fig. 1 illustrates the LTE released version 8 CRS position when 3 different frequency displacements.

Fig. 2 A shows the method according to the first and second embodiments, and Fig. 2 B shows the equipment according to the first and second embodiments.

Fig. 3 illustrates the traditional C oMP scheme with cooperation CRS, allows to cooperate on other RE.

The Cooperative District that Fig. 4 shows the RE stoped in community (cell) 3 according to the first embodiment, size reduces due to CRS.

Fig. 5 shows the data based on all communities, CRS(scrambling (scrambling), seed (seed) etc. according to the first embodiment) and the knowledge of estimated radio channel and the precompensation entering the interference of the Cooperative District that size reduces that the CRS due to non-cooperation community is caused.

Fig. 6 shows the basic conception of the CoMP according to the second embodiment.

Fig. 7 illustrates the PDCCH mismatch of 3 community CoMP transmission.

Fig. 8 A to 8C shows the Cooperative District of the different sizes of the number according to the community stoped owing to still running PDCCH transmission in other communities according to the second embodiment.

Fig. 9 A to 9C show according to the second embodiment for the demodulation of different phase to an only subscriber equipment (UE3).

Figure 10 illustrates the interference changed on a PRB due to the cooperation eNB of variable number according to the second embodiment and BER.

Figure 11 A shows the method according to the 3rd embodiment, and Figure 11 B shows the equipment according to the 3rd embodiment.

Figure 12 illustrates the CoMP district with 4 eNB, and it has the antenna element of different number about the third and fourth embodiment.

Figure 13 A and 13B shows the method according to the 4th embodiment.

Figure 14 A and 14B shows the equipment according to the 4th embodiment.

Figure 15 illustrates comprehensive (integrated) RS scheme according to the 4th embodiment.

The CSI that Figure 16 illustrates CRS, CSI-RS and pDRS when applying the process according to the 4th embodiment estimates the typical characteristics of accuracy and may merge the result of gain.

Figure 17 shows may distribute the pDRS that two subsequent subframe merge according to the 4th embodiment.

Figure 18 to 20 shows the simulation result of the process according to the 4th embodiment.

Embodiment

Below, the overall and concrete example with reference to embodiment describes embodiments of the invention.But should be appreciated that this description only exemplarily provides, and described embodiment never should be understood to limit the invention to this.

first embodiment

According to the first embodiment of the present invention, consider the CoMP transmission (such as, as defining in released version 8) combined with frequency displacement.

Prior art related to this is below described.

For LTE released version 8, define the grid (grid) of so-called public reference signal (CRS).Such as, each 6th subcarrier place of antenna port AP1 in OFDM symbol 1,5,9 and 12 has RS.Because LTE is the cellular radio system with frequency reuse 1, therefore all cell transmission have the specific CRS in community of specific scramble sequence.In order to the presence of intercell interference between reducing from the CRS of different districts, define other 3 different so-called frequency displacements, this means: at the OFDM symbol place of correspondence, the CRS of community 1 starts with such as subcarrier (SC) SC1, the CRS of community 2 starts with SC2, and the CRS of community 3 starts with SC3.Frequency displacement is closely coupled to community ID, and the CRS avoided from neighbor cell always conflicts mutually with the identical RS signal from other communities, thus improves overall (many) cell channels estimation accuracy.

Mobile Network Operator (MNO) can by controlling frequency displacement by the cell ID allocation of correspondence to website.

In LTE released version 8, each community can by not for CRS use all its Resource Units (RE) for the transfer of data on so-called physical down link sharing channel (PDSCH).

As mentioned above, so-called cooperation or cooperative multipoint transmission (CoMP) have been identified as one of major technique improving spectrum efficiency.Because advanced LTE is regarded as the evolution from LTE released version 8, the therefore complete back compatible of General Requirements.This comprises: should completely according to LTE released version 8 to transmit CRS.About the frequency displacement from released version 8, if the RE of carrying CRS has different frequency displacement, so this conflict causing eNB to cooperate in different cooperation community.These RE are in a cell data case (data bin) and carry in other CRS, thus avoid transmitting from all communities simultaneously.

In advanced LTE, as developing direction, reach an agreement: will the so-called CSI-RS being used for CSI estimation sparse over time and frequency be there is, and in addition, by the pDRS existed in the resource of CoMP or the 8TX antenna being used for demodulation.In addition, released version 8 CRS will be there is, its objective is, for released version 8 UE, there is back compatible completely.

As mentioned above, particularly, for released version 8, the cell specific frequency shift of definition is a challenge concerning CoMP system, and wherein, all eNB must transmit the data-signal of suitable precoding on identical RE simultaneously.

This challenge becomes clear from Fig. 1.Fig. 1 shows the LTE released version 8 CRS position when 3 different frequency displacements.Particularly, in FIG, the fraction of so-called Physical Resource Block (PRB) is shown for 3 communities.PRB is formed by 12 SC and 14 OFDM symbol, forms the so-called subframe that length is 1ms.Show only 3 in 12 SC, because be enough this this.Can clearly be seen that, for each community, give different frequency displacement, this means: the displacement of a CRS SC.Owing to transmitting from all eNB public impossible these RE simultaneously, therefore prevent the cooperation on the RE of carrying CRS in one of community.

Here only an AP(is analyzed namely, AP0), but basic scenario is to other AP(namely, AP1 to AP3) also quite similar.

The other problems that must consider is: for CoMP transmission, there is the strong trend becoming so-called transparent precoding solution, this means that UE does not know the precoder in the application of eNB place.For this reason, such as, developing direction is reached an agreement: by special for so-called precoding RS(pDRS) for the demodulation at UE place, thus allow any pre-coding scheme when not having clearly the notifying of UE.

As mentioned above, as the solution to shift problems, propose: the community ID in network is controlled, different frequency displacement can be avoided.

This solution has its advantage, because it does not need any change to LTE or advanced LTE, because the network planning is allowed by MNO now.But, there are some key issues, as:

-estimate that accuracy may be influenced based on the multi-cell channel of non-displacement CRS, make at least to reduce released version 8 UE performance.

, some impacts (interference randomization such as reduced) on PDCCH may be there are in-displacement owing to losing in front 3 OFDM symbol.

-MNO may have LTE released version 8 network of operation, and wherein, community ID has been assigned with the frequency displacement of its correspondence, therefore, may cause some troublesome RRM(provided for radio resources management to the reorganization of community ID) problem.

-community the ID with its corresponding frequency displacement also defines what is called and to advocate peace the code of auxiliary (primary and secondary) synchronizing channel (PSS/SSS).Therefore, when not having frequency displacement, owing to using less code, therefore general synchronization process may be influenced.

-in the vicissitudinous LOS(sight line of tool) and NLOS(non-line-of-sight) condition cover by force (shadowing) situation under, eNB at a distance may be there is as most strong interferers (interferer).For this reason, in this case, much bigger by force to the definition of the customer-centric of Cooperative District, this is that the most strong interferers seen based on UE due to it defines Cooperative District.This make the frequency displacement of plot planning avoid become complicated.The unique possibility solving this point is: apply identical frequency displacement in the entire network.

Another possibility overcoming this problem can be: be used in adjacent radio cells the blanking (blanking) carried on the RE of CRS.This is clean solution.Meanwhile, it causes the significant amount of overhead of about 30% of support for only 2 AP.This expense is regarded as undue large.

Therefore, the released version of LTE backward 8 that the object of the present embodiment is to provide for the CoMP transmission scheme of advanced LTE can compatible solutions, and it allows the relevant precoding when having the CRS of different frequency displacement for cooperative wireless electricity community.

According to the present embodiment, cooperation is limited to current those eNB and UE not transmitting any CRS of Cooperative District.

Describe the more overall example of the first embodiment referring to Fig. 2 A and 2B, wherein, Fig. 2 A shows the method according to the first embodiment, and Fig. 2 B shows the control unit (CU) of the example as the equipment according to the first embodiment.

In fig. 2, show the overall example of the method according to the first embodiment, in the method, the cooperative multipoint transmission between network control unit and terminal on Resource Unit is controlled.In step s 11, detect Resource Unit and whether comprise discrete cell, and in step s 12, when detecting that Resource Unit does not comprise discrete cell, select the Resource Unit for the Mobile Transmission that cooperates.

Fig. 2 B shows the example of the equipment according to the first embodiment.Here, assuming that this equipment is central location (CU) or its part, but alternatively, this equipment can be other suitable element (as NodeB or eNodeB) or can be its part.This equipment comprises transmission control unit (TCU) (device for controls transfer) 11, the cooperative multipoint transmission between net control control unit and terminal on Resource Unit.In addition, this equipment comprises: detector (checkout gear) 12, and it detects Resource Unit (RE) and whether comprises discrete cell.In addition, this equipment comprises: selector 13, and when detecting that Resource Unit does not comprise discrete cell, it selects the Resource Unit for the Mobile Transmission that cooperates.

Note, transmission control unit (TCU) 11, detector 12 and selector 13 can provide as a unit.That is, such as, CU or eNode-B(is not shown) controller can be configured to the function performing these unit.Therefore, according to the first embodiment, only use those Resource Units not comprising any discrete cell, it is actually used in cooperation Mobile Transmission (CoMP).

According to the more specifically example of the first embodiment, discrete cell comprises reference signal, such as above-mentioned public reference signal (CRS).

In order to understand better, referring to Fig. 3 and Fig. 4.Fig. 3 shows the traditional C oMP scheme with cooperation CRS, allows to cooperate on other RE.The Cooperative District that when Fig. 4 shows the RE stoped in cell 3 according to the present embodiment, size reduces due to CRS.Can for from eNB3 to UE ₁and UE ₂known aerogram channel correction from the interference caused due to its CRS of the CRS of community 3, as will be described below.

In figure 3, assuming that do not have frequency displacement, this may such as be ensured by the network planning of correspondence, ignores its inferior position as above.In this case, from the angle of CoMP, this situation is easy, and when not having CRS, all RE provides service to all 3 UE.The RE with CRS is not used for cooperation, but only can the transmission of compatible CRS for released version 8.

In the diagram, frequency displacement is introduced.Traditionally, this will mean: will not there is cooperation (see such as RE2, wherein, its CRS signal is transmitted in community 3) on these RE.

Here, propose, for this RE, cooperation is limited to community 1 and 2, thus cooperation gain as much as possible can be realized.Meanwhile, compared with conventional cases, by the inferior position that the interference existed owing to causing from the CRS Signal transmissions of community 3 increases.But here, must remember: known interference is not interference.This opens two different options:

A) eliminate based on the interference carried out at UE from the known radio channel of community 3 to UE1 and UE2 and the known CRS with the specific scramble sequence in its respective cell, frequency displacement etc.This will cause opaque solution, because UE must know all community ID it being provided to service, to calculate corresponding CRS signal transmission and by itself and corresponding radio channel h ₁₃and h ₂₃be multiplied.In addition, must known precoding.In this case, its decoded signal only can be deducted h by UE ₁₃* Tx _{cRS, cell3}(Tx _{cRS, cell3}community 3(cell 3) the signal transmission of CRS), thus obtain glitch-free version.Note, in any case at the known community ID participating in cooperation of UE place possibility, with regard to relevant precoding, the correspondence of the radio channel of these communities must be organized to report, but precoding may change quite fast.

B) by the directly process interference owing to causing from the CRS of community 3 in central location (CU) of corresponding precompensation, be so possible to the solution that UE is completely transparent.At CU place, in any case at least for the relevant precoding solution investigated here, all information (from all eNB to the cooperation community etc. of the radio channel of all cooperation UE, frequency displacement, community ID, scramble sequence, current PRB) will be available.This allows the h deducted at CU place for UE1 ₁₃* Tx _{cRS, cell3}with the h for UE2 ₂₃* Tx _{cRS, cell3}.

Fig. 5 shows the schematic diagram of proposed precompensation, and illustrates the data, CRS(scrambling, seed etc. based on all communities) and the knowledge of estimated radio channel and the precompensation entering the interference of the Cooperative District that size reduces that the CRS due to non-cooperation community is caused.As shown in Figure 5, only community 1 and 2 CoMP participating transmission.Because the interference caused from the CRS of community 3 to UE1 and UE2 is by being represented as h ₁₃and h ₂₃double dashed arrow instruction.

According to the scheme of the present embodiment, there is multiple advantage:

-it allows and shows that released version 8 CRS of cell specific frequency shift can the solution of back compatible completely.

-which obviate the hydraulic performance decline estimated about PDCCH or synchronous any complex situations and multi-cell channel based on PSS/SSS caused due to the frequency displacement lost.

-do not need specific cell ID to plan.

-this solution is completely transparent, and this is major advantage.As mentioned above, about UE, nontransparent solution is also possible.UE can not know shift problems completely, and does not have any extra process demand.

-there is not the limited and hydraulic performance decline caused of size due to Cooperative District, because this is typical case.In order to understand this point, must remember: the relevant precoding of application, to overcome presence of intercell interference and to eliminate this interference in Cooperative District, makes the interference of only cooperative internal to exist.In the sense that, eliminated by the precompensation of correspondence and create the effect identical with the effect of the actual cooperation with this community because CRS transmits the interference caused.

-in addition, when having frequency displacement and do not have frequency displacement, the sum of spendable resource does not change for the scheme proposed simplifying rate-matched.For the traditional cooperation without frequency displacement, a RE in the middle of existence three RE is not used for PDSCH by any community.Therefore, always co-exist in 2 RE 3 UE being provided to service, that is, in the middle of 9 data boxes altogether 6 may be used for transfer of data.In cases where the frequency shifts, existence 3 being taken advantage of 2 UE serviced, is equally also 6 in the middle of 9 data boxes.

-when relevant precoding, do not need additional feedback or channel estimating, but if correspondingly design overall scheme, then all information needed can be used.

second embodiment

According to the second embodiment, with similar in the first embodiment, also contemplate the reference unit that comprises discrete cell and be not used in CoMP.But according to the present embodiment, the example of this discrete cell is control channel symbol, as PDCCH symbol.Below this point will be illustrated in greater detail.

That is, the second embodiment relates to the CoMP solution when PDCCH mismatch, as will be described below.

Below first prior art related to this is described.

As already mentioned, in the background technology part of the application, for advanced LTE, so-called cooperative multipoint transmission (CoMP) is investigated in research project, and reach an agreement in developing direction, that is, existing should the sparse RS that estimates for CSI and the precoding DRS (Dedicated Reference Signal) (pDRS) for demodulation over time and frequency.PDRS is for demodulation and only transmit on those PRB with transfer of data, thus has saved unnecessary expense.The precoder identical with corresponding data-signal is utilized to carry out precoding to pDRS.

CoMP UE(namely, the UE of CoMP participating transmission) controlled physical down link transmission channel (PDCCH) is upper by so-called anchor (anchor) community.Each UE is connected to its anchor community, and wherein, this anchor community is selected based on the strongest received power.

For the PDSCH transmission of the data of relevant precoding, all cooperation eNB transmit in same asset simultaneously.

As long as the number of the PDCCH symbol in all cooperation communities (can change the number of OFDM symbol according to LTE released version 8, PCFICH between 1 with 3) is identical, this just produces good effect.Usually, for each subframe, each community may have the PDCCH OFDM symbol of different number, the cooperation on front 3 symbols of each subframe is become and is rich in challenge.If cooperation is restricted to 11 OFDM symbol (its be connected on front 3 OFDM symbol after) all the time, then cause quite significant expense.

Therefore, the object (but being not limited thereto) of the present embodiment is: allow the transparent of relevant precoding CoMP solution and support efficiently, thus allows the PDCCH OFDM symbol for the different numbers of each community of Cooperative District.

That is, the problem that solve be when the variable of every subframe and the OFDM symbol of especially different number the relevant precoding of PDSCH in Cooperative District.Note, subframe has 1ms length, comprises 14 or 12 OFDM symbol, and has 1 to 3 OFDM symbol for PDCCH, and wherein, PCFICH indicates the length of the PDCCH of present sub-frame.

In figure 6, the principle relevant to CoMP is shown.Fig. 6 shows in detail the basic conception of CoMP: the cooperation on PDSCH, and each UE only monitors the PDCCH of its anchor community, that is, PDCCH does not exist cooperation.PDCCH is indicated by the double-head arrow with solid line, and CoMP transmission is indicated by single arrow, and (solid arrow is used for UE _a, large hatched arrows is used for UE _b, small opacities line is used for UE _c).

As mentioned above, object is: the concept keeping released version 8 as much as possible, that is, maintain back compatible.In addition, physical layer (PHY) should be separated with more high-rise.

Therefore, propose each UE and only monitor its anchor community (being sometimes also referred to as Serving cell), this anchor community selects in switching (HO) period caused due to peak signal power.In addition, PDCCH is similar to released version 8, other CCE(control channel unit of some of them) for the C-MIMO(cooperation multiple-input and multiple-output to UE) pattern carries out semi-static selection and defines the Report mode (community ID, time frame etc.) of UE.The advantage realized is: advantage is, quick switching between C-MIMO and single community Tx is possible, can reuse released version 8 feature as much as possible, UE transparent precoding solution is possible, and the confusion with community and the specific scrambling of UE may can not occur.

About pDRS, note, they are orthogonal at least 8 streams, and the FDM/TDM/CDM often flowed is possible, and the more high-level signaling (RRC) of the sequence number often flowed is possible.In addition, semi-static adaptation is possible together with C-MIMO pattern.Alternatively, fixing community is possible to the mapping of stream.

Fig. 6 illustrates the concept of anchor community, and wherein, each anchor community controls its UE.Thus, more or less completely the same with LTE released version 8, transmit PDCCH without coordination.Assuming that only need seldom new RRC information for advanced LTE, such as UE is semi-statically set to CoMP pattern, and thus the identical controlling mechanism entered into force can be reused.This comprises the abundant covering of PDCCH message and presence of intercell interference robustness fully.

For the transfer of data of PDSCH signal, anchor community and the anchor community of Cooperative District are transmitted simultaneously, to realize from the larger performance gain of the hope of relevant precoding.For relevant precoding, PHY layer with more high-rise between exist and be easily separated.This means: precoding (PHY) is carried out from different districts cooperation, and community and the specific scrambled code of UE and interleaver, UE RNTI(radio network temporary identifier) etc. will define based on anchor community, and it will be that network correspondingly transmits cooperating of task to cooperation.

As already mentioned, the complete backward compatibility of advanced LTE and released version 8 should be realized.For released version 8, define so-called public reference signal (CRS), and usually understood, these CRS must have been transmitted continuously for complete backward compatibility.CRS may be used for carrying out demodulation to PDCCH signal, because these are only from anchor cell transmission.First OFDM symbol will be PDCCH symbol all the time, make to use CRS all the time for this symbol.

As already mentioned, in advanced LTE, as developing direction, by the CSI-RS being used for CSI estimation sparse in life period and frequency, and in addition, precoding DRS (Dedicated Reference Signal) (pDRS) will be there is in the resource of CoMP or the 8TX antenna for demodulation.

PDRS carries out precoding with data by identical CoMP precoder, makes this precoding be transparent concerning UE, this means: these UE need not know the precoder for demodulation.These pDRS can/must be used for carrying out demodulation to the relevant precoded signal in last 11 OFDM symbol of subframe.

(critical area) is OFDM symbol #2 and 3 in critical zone, and for these symbols, transmission PDCCH signal (Jin Yige community) may be wanted in some communities, and other communities want cooperation to transmit PDSCH data.

In the prior art, identify the different options how processing the problems referred to above, such as, CoMP transmission is limited to last 11 OFDM symbol 9 OFDM symbol of extended cyclic prefix (or for), to the fast signal notice of the PFCICH of every community and adaptive to the correspondence of transmission, public control area to be used for equal length CoMP transmission etc.

Particularly, interest is following proposal: the non-CoMP transmission using PDSCH signal when one or more community still has some PDCCH signals in this OFDM symbol.

The inferior position of this solution is: for front several non-CoMP PDSCH OFDM symbol, must use CRS, and for the remainder of subframe, pDRS must be used for demodulation.Therefore, this proposal improves UE complexity, it is nontransparent, because must to UE notice whether must based on CRS or pDRS to second and the 3rd OFDM carry out demodulation, and this proposal generates for each subframe and is used for a large amount of control overheads that signaling is in the OFDM symbol of CoMP pattern.

According to the present embodiment, propose the special process of front 3 symbols, wherein, only these communities relate to CoMP, and wherein, symbol is not used in PDCCH.Therefore, front 3 symbols also may be used for CoMP.Below this point will be described in more detail.

Particularly, similar described by the updating currently form of the present embodiment and above combination the first embodiment as shown in Figure 2 A and 2B.That is, substantially, only these Resource Units are used for CoMP, and these Resource Units do not comprise discrete cell, and in the case of the second embodiment, this discrete cell is the control channel symbol (such as, PDCCH symbol as above) used for control channel.Therefore, according to the general type of the second embodiment with similar according to the general type of the first embodiment; Therefore, do not repeat it here to describe in detail.Note, according to the second embodiment, detector can be configured such that it is by reference to such as PCFICH(physical control format indicator channel) and so on control format designator whether comprise discrete cell to detect Resource Unit, it indicates the number of control channel (as PDCCH) OFDM symbol.Like this, which Resource Unit can clearly be detected or symbol comprises control channel symbol.

With reference to Fig. 7, this embodiment is described in more detail.

Particularly, in the figure 7, challenge relevant with the mismatch of PDCCH length in different cooperation community is illustrated in more detail.For last 11 OFDM symbol, cooperation is easily possible, and in front 3 OFDM symbol, due to PDCCH transmission, what still may stop in cooperation community is one or more.

In the figure, assuming that exist, there is 1 PDCCH OFDM symbol a community, and there are 2 PDCCH OFDM symbol a community, and there are 3 PDCCH OFDM symbol the 3rd community.

Here, propose application cooperation as much as possible, namely, as long as every other community is still in PDCCH pattern just start (the 2nd OFDM symbol with single cell transmission, vertical shading Xian Kuai community 3), and partly cooperate between community 1 and 3 on the ofdm symbols, wherein, PDCCH(the 3rd OFDM symbol is not transmitted in more than one community, horizontal shading line block).

In Fig. 8 A to 8C, illustrate basic conception, Fig. 8 A to 8C illustrates the Cooperative District of the different sizes of the number according to the community stoped owing to still running PDCCH transmission in other communities.Fig. 8 A illustrates the stage 1, and wherein, community 1 and 2 is broadcasted its PDCCH, and its PDSCH is transmitted in community 3.Fig. 8 B illustrates the stage 2, and wherein, community 2 and 3 starts cooperation, and community 3 completes its PDCCH and transmits, that is, there are 2 community CoMP transmission.Fig. 8 C shows final stage, i.e. the stage 3, wherein, cooperative provides service to all UE.

First view is looked, and this seems even more complicated, and seems to further increase control overhead.In addition, it needs for the situation of 2 the cooperation eNB pDRS different with the situation of 3 cooperation eNB, thus makes situation become complicated.Following content is disclosed to the research more deeply of this theme: eNB can easily process this situation, and permission UE is carried out demodulation based on pDRS signal to its PDSCH data all, and has nothing to do with the number of cooperation community.For this reason, in Fig. 9 A to 9C, analyze single UE(UE3) radio channel.

Fig. 9 A to 9C shows for the mono-cell transmission of stage 1(as above described in composition graphs 8A to 8C) to the whole CoMP of stage 3() for, to the analysis of the only demodulation of UE 3, wherein, Fig. 9 A shows the stage 1, Fig. 9 B shows the stage 2, and Fig. 9 C shows the stage 3.According to this figure, in the stage 1, must for radio channel h ₃₃carry out demodulation (single cell transmission); For the stage 2, for aggregate channel h ₃₁and h ₃₃carry out demodulation; And in the end the stage comprises, for all radio channel h ₃₁, h ₃₂and h ₃₃carry out demodulation.

Phase III is traditional C oMP transmission, and for demodulation, employs the pDRS of correspondingly precoding.Utilize precoding weight w ₃₁, w ₃₂and w ₃₃, UE based on carry out it to estimate, a is the overall amplitude of precoding radio channel, and it is corresponding phase place.Data-signal stands identical precoding and radio channel, makes demodulation be easily possible.

When single cell transmission, the demodulation based on pDRS will the failure due to channel mismatch.Precoding (w-will do not had _{33, single cell}=1) at radio channel h when ₃₃upper transmission PDSCH data.But must remember: for relevant precoding, eNB must know all involved (virtual) radio channels based on the quantification feedback of all UE.

When knowing all radio channels, eNB can be single cell transmission during easily apply precompensation to PDSCH, make UE directly can reuse pDRS to carry out demodulation, and be have nothing to do from one, two or all cell transmission with PDSCH.Note, the precompensation weight of 2 cell transmission can be derived similarly with single cell transmission.

During single cell transmission, for part or all of cooperation, naturally there is the interference of how inner Cooperative District.Thus, the BER(bit error rate of every symbol) will change in time.In Fig. 10, the BER obtained on the number of cooperation community is schematically indicated about symbolic number.That is, Figure 10 illustrates the BER in the interference (I) and a subframe that change due to the variable number of cooperation eNB.For this reason, according to the present embodiment, propose intertexture corresponding to application to avoid burst error.Another option will be the different MCS(modulation and the encoding scheme that use every OFDM symbol), but this will need corresponding signaling, and thus will the transparency of this solution be violated.

As further improvement, even may expect further precompensation that the PDCCH of other communities is disturbed or elimination, because these are concerning being known eNB or can estimating based on PDCCH signal and involved radio channel.

Therefore, following advantage is present embodiments provided:

-provide full flexibility for the length of the PDCCH of the different districts of Cooperative District.

-according to the PDCCH signaling of anchor community, all available resources may be used for PDSCH transfer of data (as in R8).

-avoid any other to control or the completely transparent solution of UE of signaling consumption.

-complicated UE process is unnecessary.

-all complexities are transferred to eNB side.As another solution, to UE, eNB may notify that whether it carry out precompensation based on proposed scheme or whether it carries out the more simple scheme of restricted data transmission in such as last 11 OFDM symbol and so on, to avoid the processing expenditure of eNB side.If volume marginal is not too strict, then this may be useful.

Note, in the first and the second embodiments described above, be referred to reference signal (as CRS) and control channel symbol (PDCCH), as the example of the discrete cell that can comprise in a resource unit.But embodiment is not limited to these examples.That is, the signal of any type or symbol can be this " discrete cells ", as long as it has counter productive to CoMP transmission.

3rd embodiment

3rd embodiment relates to the space division multiplexing (SDM) designed for minimal-overhead pDRS, but is not limited thereto.In detail, according to the 3rd embodiment, the optimum allocation of the pre decoding reference signal (pDRS) to cooperation multicast communication (CoMP) can be realized.

Below illustrate in greater detail this point, wherein, first describe prior art related to this.

As already mentioned, for advanced LTE, cooperative multipoint transmission (CoMP) is investigated in research project (SI), and reach an agreement in developing direction, that is, existing should the sparse RS(CSI-RS estimated for CSI over time and frequency) and for the precoding DRS (Dedicated Reference Signal) (pDRS) of demodulation.PDRS is for demodulation and only transmit on those PRB with transfer of data, thus has saved unnecessary expense.The precoder identical with corresponding data-signal is utilized to carry out precoding to pDRS.Because pDRS must support the demodulation to most high modulation and encoding scheme (MCS) (as 5/6QAM64), therefore they must provide channel estimating very accurately, be attended by the larger expense of correspondence of the RS of every PRB.

Another relevant issues are: advanced LTE will support every community 8 TX antennas at the most, and when CoMP system, easily, may cooperate in 5 or even more communities.From the angle of channel estimating, this means: when flat-footed realization, 5x8=40 channel must be estimated, that is out UE ability, and cause high channel estimating and reference signal expense in addition, particularly for pDRS.

PDRS carries out precoding with data by identical CoMP precoder, makes precoding concerning transparent UE, this means that these UE need not know the precoder for demodulation.Current, such transparency is favourable.

PDRS will provide extraordinary estimation accuracy based on resource sufficient concerning pDRS.When for relevant precoding, pDRS will benefit from Wave beam forming gain, and by each stream needed for existing or the orthogonal precoding RS of UE.Orthogonalization can be carried out in time domain, frequency domain or code domain (TDM/FDM or CDM).There is a stream when such as supporting that 4 UE(are each) the Cooperative District of 5 communities, then will there are 4 minimum orthogonal pDRS.Each pDRS can by about 4 to 6 Resource Unit supports.When 4 to 8 Tx antennas, the expense of pDRS is easily increased to the 20-30% of each scheduling PRB.Because CoMP expection is used for expense condition, therefore easily, its can be 80% UE be in CoMP pattern, that is, the overhead of pDRS will reduce about 20% only on a small quantity.

Additional RS(aRS) (being also referred to as CSI-RS) expection is used for CSI and estimates.CSI estimates to be fed back to eNB by UE, makes these eNB can apply suitable precoding.

CSI-RS density must be suitable for coherence time and the frequency selectivity of radio channel, and must fully suppress multiple cell RS interference.Performance needed for CSI estimates must match with the precoding accuracy of expection, and thus depends on overall pre-coding scheme.The emulation of single Cooperative District shows: to be concerned with pre-coding scheme for advanced person, by the mean square error MSE in needs 0.1 to 0.01 scope, thus easily to cause the additional CSI RS expense of about 10%.

For the CRS of such as CRI-RS and so on, identical CSI-RS can be used for channel estimating by all UE, and the number of overall overhead and UE is had nothing to do.Meanwhile, for the CoMP combined with 8Tx antenna and such as 5 communities, CSI RS expense will easily expand rapidly.

In developing direction, seem to exist for the possible direction of two of minimizing overall RS expense, that is: i) minimize the expense of CSI RS; Or ii) minimize the expense of pDRS.

Note, according to the present embodiment, adopt second direction, that is, according to this embodiment, when supposing to estimate based on the accurate channel of CSI-RS, when not sacrificing performance, significantly minimize the pDRS expense of relevant precoding CoMP solution.

In order to provide orthogonal pDRS, the many different modification that TDM/FDM and CDM having investigated the RS of every PRB at present distributes.

Recently, propose: if additionally expense uprises, then allow the channel estimating based on the pDRS on multiple subframe or PRB.Expense expands on multiple PRB by this, thus allows the RS decreased number of every PRB.

The object of the present embodiment is (but being not limited to): even if when cooperation enhancing Node B (eNB) number is larger, also significantly reduce the pDRS expense of relevant precoding solution.

The method of the overall example according to the present embodiment is described referring to Figure 11 A and Figure 11 B.Figure 11 A illustrates the method for the overall example according to the present embodiment.The method controls the transmission of reference signal in the Resource Unit of Resource Block in the cooperative multipoint transmission between network control unit and terminal.In the step s 21, for reference signal sequence, use the single reference signal (as pDRS) of all terminals, wherein, in step S22, for each terminal, spatial pre-coding is carried out to this single reference signal.

Figure 11 B shows the equipment of the overall example according to the present embodiment.This equipment can be network control unit (as central location (CU) or NodeB(or eNodeB)) or can be its part.In the example of 6 b it, this equipment is a part for central location.This equipment comprises: controller 21, it is configured to control reference signal (as the pDRS) transmission in the Resource Unit of Resource Block in the cooperative multipoint transmission between network control unit and terminal, and for the sequence of reference signal, single reference signal is used for all terminals.In addition, this equipment comprises: precoding unit 22, and it is configured to carry out spatial pre-coding to the single reference signal of each terminal.

Therefore, the pDRS in the sequence of the reference signal in multiple subframe is only for the demodulation under spatial pre-coding.

Therefore, pDRS expense can significantly be reduced.

Note, transmission control unit (TCU) 21 and precoding unit 22 can provide as a unit.That is, such as, CU or eNode-B(is not shown) processor can be configured to the function performing these unit.

Preferably, according to this embodiment, in the first subframe, orthogonal reference signal (as pDRS) can be used, make in the impossible situation of perfect precoding, the estimation to interference can be allowed.

Therefore, according to the present embodiment, use the spatial pre-coding (Wave beam forming to UE) to pDRS, instead of the orthogonal guide frequency of each UE.That is, a pDRS of sequence can be orthogonal, and to allow the estimation etc. to interference, and the following pDRS in sequence is only for demodulation (when spatial pre-coding).Therefore, pDRS expense can significantly be reduced.

In more detail, according to the present embodiment, the multiple subframes on identical PRB are dispatched the UE of cooperation.That is, according to this embodiment, not that the RE of the pDRS making every PRB reduces, but propose and first make the PRB with pDRS of all space layer use.This permission is estimated the accurate channel of the first subframe, and will provide higher CoMP gain.

In following subframe, utilize the concrete property of the cooperation of relevant precoding, that is, in ZF(ZF) type precoding, will all interference in cooperation be eliminated or cooperate interior all interference reductions to predefine value to major general.For this reason, pDRS single set by TDM, FDM or CDM orthogonalization, but need not can be reused in all UE by application space division multiplexing (SDM) by demodulated reference signal.

The expense of pDRS is reduced to the expense of single stream by this from such as 5 or more streams.In principle, for this purpose, the standardized AP5 from LTE released version 8 can be reused.

When perfect precoding, also can avoid often flowing or UE carries first subframe of orthogonal pDRS, and only can apply SDM from the outset, thus reduce expense further.

Enter other directions, some other advanced LTE pDRS PRB can be added every now and then, to make the strong channel variation of estimation of system more interference between robust or process stream.This such as can be configured by eNB and may by more high-level signaling configuration.If SDM continuous service and the pDRS added is on other RE, be then possible to the solution that UE is transparent.

In addition, alternatively, only pDRS can be used in same resource units.That is, can only for one or two interference flow transmission orthogonal reference signal.This scheme allows to come only to send additional orthogonal RS for several stream based on TDM, FDM or CDM, UE can be known over multiple subframes and disturb between all stream.Like this, still can minimal overhead, but on the other hand, improve the robustness of transmission.

Figure 12 has the CoMP district of 4 eNB by signal, shows the basic conception that the SDM of the pDRS of the cooperation UE according to the present embodiment is multiplexing.Schematically show a relevant precoding space layer x to UE _xtransmission (being indicated by diagonal angle hacures) and its interference to UE _ktransmission (being indicated by some hacures).

First, briefly to describe in conjunction with Figure 12 and the symbol used in the present embodiment:

K: the stream of a stream of every UE or the # of UE

K:UE index; K ∈ 1 ... K

V _{nc × nt}: the precoder of virtual-antenna

W _{ntv × k}: pre-coding matrix

H _{k × ntv}: channel matrix

P: precoding correction matrix

RS _i: the reference signal of space layer i.

Figure 12 shows central location (CU) (wherein, the function of precoding unit is indicated by W*V), by multiple reference signal (RS ₁, RS ₂... RS _k) and data-signal (d ₁, d ₂... d _k) be supplied to central location (CU).Unlike signal is sent to by NB from CU ₁to NB ₄the different N odeB of instruction, it comprises the antenna element (by being that hatched arrow indicates with horizontal line) of different number respectively.These different N odeB provide service to the multiple UE in this district, and these UE are by UE ₂, UE ₄, UE _kand UE _x-instruction.

Note, be that hatched arrow indicates from layer x to the interference of layer k with vertical line, wherein, layer x indicates NodeB and UE _xbetween connection, and layer k indicate NodeB and UE _kbetween connection.

Below, the pDRS CSI estimation procedure according to the present embodiment is summed up with reference to Figure 12:

-owing to utilizing the almost ideal precoding of W*V, assuming that from other UE interference ( ) be 0 or very low.

-when there are some residual interference, a PRB of the sequence of PRB for estimating that these disturb, and such as makes least mean-square error (MMSE) receiver be suitable for disturbing between minimum stream.

-in the overall transmission time that this PRB goes here and there, MMSE receiver will be retained as constant.

-for following PRB, utilize the specific pDRS R in the same cells of all spatial flows ₁=R _i=R _kbut utilize different spatial pre-codings to provide service to UE.For this reason, the RS of each UE and data use identical precoder W*V.

-when perfect precoding, as when TDM, FDM or CDM, when not needing multiple RE, UE receives its demodulation pDRS when the interference not from other UE.

-according to intermediary solutions, there is (or multiple) additional orthogonal (TDM, FDM, CDM) pDRS signal of (or multiple) data flow in each xth subframe.By changing the stream sending orthogonal pDRS for it, UE can know the whole interference from other data flow in time.It allows the balance between robustness (adaptive MMSE UE Beam-former) and expense.

Note, consistent with the developing direction of advanced LTE to the application of SDM for pDRS, because pDRS only expects for demodulation.The orthogonal pDRS that often flows allows to estimate the interference at UE place and knows the more contents relevant with total radio channel condition, but owing to not using this information, it is irrational for therefore expending any expense for this reason.

Therefore, the 3rd embodiment provides following advantage:

-the solution that proposes significantly reduces the pDRS expense of relevant precoding CoMP solution, and this is regarded as high performancely most being hopeful candidate.

-be easily be in the scope of 20% to 30% by the overhead computational of pDRS, this is the actual burden of effective CoMP solution.Proposed by application SDM, this can be reduced to several percentage points, similar with the AP5 in LTE released version 8.

-this solution is very simple in realization, and may concerning completely transparent UE.

If-within the whole time, apply SDM, then AP5 can be reused in this solution, thus avoid further standardized any needs.Therefore, this solution can easily be realized.

-more robust is designed flexibly, the PRB that perception can be disturbed combine with using those PRB of SDM, to allow the balance between expense and robustness and possible performance.

-when a PRB uses orthogonal pDRS, the length that overall overhead is gone here and there with the PRB of every UE and reducing.Assuming that typically, cooperation UE has mass data will be transmitted, and therefore, can easily generate this string.

Between-the stream that causes due to precoding mistake, interference will reduce demodulation performance.These mistakes by time and along with increase translational speed and increase.Must be noted that, this is with similar for the hydraulic performance decline that CDM intersymbol interference is known.In addition, the precoding mistake of pDRS is by definitely identical with the precoding mistake of transfer of data.In the sense that, according to the concept of the present embodiment from convergent-divergent (self scaling), that is, precoding accuracy, and the precoding accuracy that the object channel estimating in order to demodulation needs will have phase same level.

4th embodiment

_-4th embodiment relates to composite reference signal (RS) design of advanced LTE and CoMP.Particularly, according to the 4th embodiment, decrease the expense of the reference signal of the channel condition information (CSI-RS) of the cooperation multicast communication (CoMP) in LTE-A.

Below describe this point in more detail, start with the description of certain prior art related to this.

As already mentioned, currently investigate cooperative multipoint transmission (CoMP), and reach an agreement in developing direction, that is, existing should the sparse RS(CSI-RS estimated for CSI over time and frequency) and for the precoding DRS (Dedicated Reference Signal) (pDRS) of demodulation.PDRS is for demodulation and only transmit on those PRB with transfer of data, thus has saved unnecessary expense.Utilize the precoder identical with corresponding data-signal to carry out precoding to pDRS, make precoding concerning transparent UE, this means that these UE need not know the precoder for demodulation.Because pDRS must support the demodulation to most high modulation and encoding scheme (MCS) (as 5/6QAM64), therefore they must provide channel estimating very accurately, be attended by the larger expense of correspondence of the RS of every PRB.

In addition, as about as described in the 3rd embodiment, advanced LTE will support every community 8 Tx antennas at the most, and when CoMP system, easily, may cooperate in 5 or even more communities, makes to estimate 5x8=40 channel at the most.

Another complicated further problem of thing is: in the cellular radio system of such as LTE or advanced LTE and so on, multiple cell interference significantly reduces CSI estimated performance, thus needs such as to carry out effective orthogonalization between cells by application community specific CDM sequence.Which in turns increases RS expense.

As mentioned above, in conjunction with the first to the 3rd embodiment, the back compatible of advanced LTE and released version 8 should be realized.For released version 8, define public reference signal (CRS), thus caused the expense of 10/15% of 2/4 antenna configuration.Usual understanding, must transmit these CRS(at least for antenna port AP0 and 1 continuously for complete backward compatibility).

PDRS will provide extraordinary estimation accuracy based on resource sufficient concerning pDRS.When for relevant precoding, pDRS will benefit from Wave beam forming gain, and will there is the orthogonal precoding RS of each stream or UE.Orthogonalization can be carried out in time domain, frequency domain or code domain (TDM/FDM or CDM).There is a stream when such as supporting that 4 UE(are each) the Cooperative District of 5 communities, then will there are 4 minimum orthogonal pDRS.Each pDRS can by about 4 to 6 Resource Unit supports.Therefore, overall overhead is easily increased to the 20-30% of each scheduling PRB.

Additional RS(aRS) (being also referred to as CSI-RS) expection is used for CSI and estimates.CSI estimates to be fed back to eNB by UE, makes these eNB can apply suitable precoding.

CSI-RS density must be suitable for coherence time and the frequency selectivity of radio channel, and must fully suppress multiple cell RS interference.Performance needed for CSI estimates must match with the precoding accuracy of expection, and thus depends on overall pre-coding scheme.The emulation of single Cooperative District shows: to be concerned with pre-coding scheme for advanced person, by the mean square error MSE in needs 0.1 to 0.01 scope, thus easily to cause the additional CSI RS expense of about 10%.

Usually, the advantage as the CRS of CRI-RS and so on is: identical CSI-RS can be used for channel estimating by all UE, and the number of overall overhead and UE is had nothing to do.Meanwhile, for the CoMP combined with 8Tx antenna and such as 5 communities, CSI RS expense will expand rapidly.

In developing direction, not yet know what meaning sparse in time and frequency is, but utilizing the initial emulation of KORAK simulator to indicate provides the CSI-RS of every Physical Resource Block (PRB) value and about 2 subframes (wherein the CSI RS 10ms of every frame) seemingly possible.Note, a frame is made up of 10 subframe 1ms.

Other known technologies are: applying virtual antenna on multiple physical antenna, typically combine with the cyclic delay diversity (CDD) as diversity scheme, thus avoid the Wave beam forming effect of the broadcast singal of such as CRS and so on.Although can obtain diversity, will lose some spatial degrees of freedom (particularly, when 8 TX antenna), this may be used for improving overall system performance.

The object of the present embodiment is: provide and have peak performance and the comprehensive solution simultaneously with the minimum overall RS expense of advanced LTE.

Therefore, according to the present embodiment, the overall RS expense of the expectation minimization such as advanced CoMP solution of relevant precoding and so on, and find the comprehensive solution allowing peak performance simultaneously.CRS, CSI-RS of being about 15-20% are added the overall overhead of pDRS by optimal situation.Expect that higher expense causes obviously being difficult to provide to expect and comparatively Iarge-scale system gain because CoMP gain must overcome additional RS expense, and in addition CoMP gain is limited to the smaller portions of total transmission time.

More specifically, following target should be realized:

-released version 8 can back compatible

The continuous transmission of → released version 8 CRS

-process developing direction " the accurate pDRS of sparse CRS+ "

-relevant precoding needs FB accurately

→ accurately multiple cell CSI

-typically, CoMP should support 1 to 2 space layer, or even when 8 Tx

-maximize the gain of CSI estimator

→ utilize all RS to carry out CSI estimation

-every eNB has the CoMP system of the community of the antenna element of different number.

According to the overall example of the present embodiment, as shown in FIG. 13A, the method that can be performed by network control unit (as eNodeB) is provided.Particularly, in step S31, orthogonal precoding DRS (Dedicated Reference Signal) (as pDRS) is sent to terminal.In step s 32, receive channel estimated result, this channel estimation results uses orthogonal precoding DRS (Dedicated Reference Signal) to set up by terminal, and in step S33, determines channel information based on the channel estimation results received.

According to the overall example of the present embodiment, the other method that can be performed by terminal (as subscriber equipment (UE)) is shown in Figure 13 B.In step S41, receive orthogonal precoding DRS (Dedicated Reference Signal), in step S42, use orthogonal precoding DRS (Dedicated Reference Signal) to perform channel estimating, and in step S43, channel estimation results is sent to network control unit.

Figure 14 shows the equipment of the overall example according to the present embodiment, and it can be network control unit, as eNodeB.This equipment comprises: transmitter 31, and orthogonal precoding DRS (Dedicated Reference Signal) is sent to terminal.In addition, receiver 33 receive channel estimated result, this channel estimation results uses orthogonal precoding DRS (Dedicated Reference Signal) to estimate by terminal.In addition, this equipment comprises: controller 32, and it determines channel information based on the channel estimation results received.

Figure 14 B shows the equipment of the overall example according to the present embodiment, and it can be terminal (as subscriber equipment (UE)).This equipment comprises: receiver 43, and it receives orthogonal precoding DRS (Dedicated Reference Signal); Controller 42, it uses orthogonal precoding DRS (Dedicated Reference Signal) to perform channel estimating; And transmitter 41, channel estimation results is sent to network control unit by it.

Note, in these two equipment, transmitter 31(or 41), controller 32(or 42) and receiver 33(or 43) can provide as a unit.That is, such as, the processor of CU or eNode-B or UE can be configured to the function or its part that perform these unit.

Namely, orthogonal precoding DRS (Dedicated Reference Signal) (as pDRS) is transferred to terminal by network control unit, terminal estimates channel (or the signal received) based on this orthogonal precoding DRS (Dedicated Reference Signal), and result is sent back to network control unit, network control unit and then calculating channel.

Therefore, perform channel estimating based on orthogonal precoding DRS (Dedicated Reference Signal), according to this standard, this orthogonal precoding DRS (Dedicated Reference Signal) is only expected for demodulation.Therefore, channel estimating can be realized by the reference signal that will be used for demodulation, makes it possible to the CRS signal reducing to a great extent to be conventionally used to channel status estimation.Therefore, expense can be reduced.

Therefore, according to the present embodiment, can as much as possible all available CSI from CRS, CSI-RS and pDRS be estimated to combine, and the dual expense of the channel estimating based on CSI-RS and the demodulation based on pDRS can be avoided.

A) due to the backward compatibility with released version 8, CRS cannot be avoided completely.In order to minimize its expense, proposing and only CRS being used for AP0 and AP1 and when virtual more than applying antenna when two AP.This can be regarded as prior art, but by the inevitable minimizing overhead of CRS to about 10%.When only AP0, being minimized to about 5% further will be possible, but this may limit released version 8 UE performance, wherein, as baseline, adopts 2x2 system.

B) because pDRS provides significant expense by when realizing good demodulation accuracy, the additional overhead of CSI-RS must therefore be minimized.For this reason, propose CSI-RS very sparse and sparse in frequency is in time provided.Very sparsely in time to mean: every frame will exist such as an only single advanced LTE subframe, caused the remarkable performance limitations to relevant precoding that the time change due to radio channel causes.Sparsely in frequency to mean: such as, an only estimated position (every 12 SC CSI-RS) in a frequency direction of every PRB.This by with every PRB expectation of feeding back feed back limit suitable.

Because advanced LTE subframe is very sparse in time, therefore the CSI RS of the quite high number of every advanced LTE subframe is possible, thus utilizes corresponding community specific CDM sequence to provide good CSI to estimate accuracy and multi-housing-area orthogonal.This provides CSI very accurately in every frame mode once and estimates.

C) described in the developing direction of advanced LTE research project, pDRS is used for demodulation.When 8 Tx antenna MIMO transmission, corresponding TDM/FDM and/or CDM must be utilized to be provided to many 8 orthogonal pDRS.From the viewpoint of CoMP, optimal situation will be the convergent-divergent to orthogonal pDRS pattern for the number of aerial stream, typically, the number of aerial stream will be only 3 to 5 streams, as when CoMP, utilize one or more data flow (seldom utilizing two data flow) to provide service to most of UE, and the typical sizes of Cooperative District is about 5, that is, cooperate in 5 communities.

D) in order to the number (#) (from being which ten more in the long run) of the physical antenna elements in Cooperative District and number (#) (as mentioned above about 3 to 5) of aerial data flow are carried out adaptation, need the virtual concept of the antenna of CoMP close friend, thus utilize spatial degrees of freedom (SDF) as much as possible.In the simplest situations, CDD can be used as Intel Virtualization Technology, but this may have two inferior positions: i) due to the diversity effect of CDD, and SDF loses; And ii) CDD will improve frequency selectivity.The frequency selectivity that CoMP is undesirably higher, because higher frequency selectivity estimates workload, more feedbacks make more difficult multi-user (MU) scheduling gains utilizing frequency selectivity by causing more CSI.

D) when CoMP, cooperative beam forms the valuable means be regarded as reducing interference between cooperation.Need to know each UE each radio channel to each eNB antenna to the selection of suitable wave beam.Meanwhile, semi-statically beam selection can be carried out.For this reason, each n-th frame, should provide the advanced LTE frame with the specific CSI-RS of antenna, thus allows to select suitable beam pattern (beam pattern).In centre advanced LTE subframe (such as each frame), CSI RS will be restricted to selected wave beam.When having the eNB of 8 Tx antennas, factor 8(a factor of 8 can be saved).

E) because each Cooperative District will need himself preliminary election beam set, therefore typically, must in time with frequency shift wave beam, and eNB must guarantee to dispatch UE in its respective resources.Otherwise every wave beam must exist CSI-RS, make each UE can estimate its radio channel for associated beam.

F) described above, antenna virtual reduction SDF, or cooperative beam forms generation a considerable amount of CSI estimation expense.In addition, typically, for relevant precoding, some included Tx diversity should be there are, thus avoid the power of ZF solution to raise.Exemplarily, the Cooperative District that size is 5 should provide service to the UE being typically less than 4.Thus, even when virtual-antenna, between the number (such as 4) of aerial spatial flow and the number (such as 10) of virtual radio radio channel, also there is mismatch.In addition, CSI RS expense will have nothing to do with the number of the UE being in fact in CoMP pattern herein.

Owing to assuming transparent precoding solution, therefore possible situation is: UE cannot carry out all radio channels of direct estimation based on pDRS signal.But, referring again to above in conjunction with the Figure 12 described in the 3rd embodiment.According to Figure 12, can deriving: except the signal of himself, disturbing between the stream that UE can also estimate (the orthogonal pDRS for often flowing) causes due to precoding mistake.As described in more detail below, eNB can use its pre-coding matrix of this feedback updated, thus eliminates residual interference.In addition, the eNB of cooperation can reconstruct radio channel based on it to the understanding of original precoding matrices, as shown in figure 15.

PDRS CSI estimation procedure according to the present embodiment is below described.

Definition (also see the description of the Figure 12 provided in conjunction with the 3rd embodiment) to variable is first described.

K: the stream of a stream of every UE or the # of UE

K:UE index; K ∈ 1 ... K

V _{nc × nt}: the precoder of virtual-antenna

W _{ntv × k}: pre-coding matrix

H _{k × ntv}: channel matrix

P: precoding correction matrix

RS _i: the reference signal of space layer i.

As follows according to the pDRS CSI estimation procedure of the concrete example of the present embodiment:

-eNB utilizes precoder W*V, in channel matrix H, orthogonal pDRS Ri is transferred to each activity (active) UE:H*W*V*Ri

-each UE k estimate based on Ri the channel of himself receive signal (S ' ^k _pDRS) and from other UE(UE _i) interference (I ' ^k _{pDRS, i})

-UE utilizes ePMI _i,kfeed back to and estimate S ' ^k _pDRS-and I ' ^k _{pDRS, i}quantized value

-eNB is by the feedback ePMI of all UE _i,kbe combined into new matrix (H*W*V) ' _pDRS, and calculate precoding correction matrix P:

For ZF, P=pinv ((H*W*V) ' _pDRS).

H*W*V*P instead of H*W*V is used for further transmission by-eNB

-alternatively, eNB utilizes H ' _pDRS=(H*W*V) ' _pDRS/ W extracts H ' _pDRS.This allows the flexible combination with other UE.

Describe this point referring to Figure 15, Figure 15 illustrates the comprehensive RS scheme according to the 4th embodiment.At the top of this figure, show ten subframes, subframe 1 to subframe 10, wherein, only in subframe 1, broadcast aRS and CRS.

In the Lower Half of Figure 15, show eNodeB(eNB1 ... and UE(UE1 L) ... k) process sequence between.In step sl, prepare the broadcast of ARS and CRS, wherein, use 1 CDM sequence of every PRB length, this 4 to 8(MSE with every antenna: ~ 0.1) corresponding.In step S152, broadcast aRS and CRS.In step S153, UE estimates channel matrix H based on aRS and CRS ' _{0, k}.In step S154, based on H ' ₀, generate ePMI0, k and fed back to eNodeB.In step S155, eNodeB is by the ePMI of all UE _{1, k}combine, thus obtain the H ' 0, q quantized.In addition, based on result, carry out scheduling about CAS, UE grouping and PRB and determine.

In step S156, eNodeB is by pDRS and pre-code data: W*V transfers to UE.In step S157, UE estimates H ' based on pDRS _{1, k}* W*V, utilizes H ' _{0, k}determine MRC, and to decoding data.In step S158, UE determines H ' ₁the ePMI of+W*V _{1, k}, and transmit it to eNodeB.

In step S159, eNodeB is by the ePMI of all UE _{1, k-}combine, calculation correction matrix P, and keep CAS, UE to divide into groups and PRBS as much as possible.In step S160, eNodeB is by pDRS and pre-code data: W*V*P transfers to UE.

UE estimates H ' based on pDRS in step S161 _{2, k}* W*V*P, and to decoding data, and by H ' in step S162 ₂ePMI _{2, k}feed back to eNodeB.After this, the process of step S159 to S162 can be repeated.

Alternatively, sometimes can also send pDRS on the current Resource Unit do not dispatched, detect these radio channels (being also referred to as " broadband detection ") to allow to determine for future scheduling.

Utilize dotted line frame in the figure to indicate the pDRS sent by this way.

Thus, the following main project of the concrete example of above-mentioned the present embodiment can be described below:

-use very sparse CSI-RS instead of CSI-RS sparse in time, provide the CSI of only few (but accurate) to estimate, typically, this CSI estimates will be out-of-date very soon.This CSI estimates for allowing the first scheduling to determine and the first more or less precoding accurately, and will be several percentage points to the overall contribution of RS expense.

-pDRS is not only used for demodulation (as described in developing direction), and be used as particular feedback, thus allow eNB its precoder adaptive or even reconstruct main (virtual) radio channel.In a first scenario, identical cooperation must be continued, and in the latter case, the new grouping of user is possible.

-due to pDRS feedback will off and on and be not to be in all PRB on (determining according to current scheduling), therefore eNB collects all available informations and also uses the most accurate and nearest CSI information to calculate pre-coding matrix all the time.As starting point, precoding is estimated based on CSI RS, and, utilize each pDRS to feed back, correspondingly will improve precoding.Meanwhile, this solution is robust, and utilizes aerial all RS signal energies to maximize performance statically.

-in addition, may there is semi-static advanced LTE subframe, thus allow the complete CSI for all physical antenna elements to estimate, this is with have 4 at eNB relevant with when more antenna element.

Below list the typical characteristics of CRS, CSI-RS and pDRS:

CRS：

-CRS is mainly used in supporting released version 8 UE.

-in order to minimize overall overhead, the target configuration of released version 8 should for 2x2 system (about 10% expense).

-in order to utilize all RS power, the MRC with aRS and pDRS estimation should be considered.

-should by selecting community ID suitably to avoid the frequency displacement in possibility CAS.

aRS：

-aRS allows the accurate CSI(8Tx demand of every antenna element), such as every frame is once

→ allow to select optimal virtual precoder (semi-static)

The CDM at-aRS top minimizes multi-cell channel interference

-for MSE<0.1 ... 0.01, CDM length should be about 4 to 8

-feedback granularity >=1PRB

→ every one, antenna is worth and PRB is abundant

→ aRS more sparse in frequency compared with released version 8 CRS

First-UE calculates the channel estimating of virtual-antenna and feeds back the PMI of every virtual A E

PMI is used for dispatching decision and calculating pre-coding matrix W by-eNB.

pDRS：

PDRS is used for demodulation by-UE

-pDRS must support that maximum MCS → MSE is about 0.01

-for often flowing (UE), pDRS is that orthogonal → each UE can estimate that self and all interference are flowed

The maximum # of-stream, is about 5 and Geng Duo for following evidence (proof) design

→ estimate to upgrade PMI or send additional PMI based on pDRS

Feedback from all UE combines by-eNB, with calculation correction pre-coding matrix P

-pDRS utilizes Wave beam forming gain and interpolation → Wave beam forming estimator gain in time

Between the CAS of-pDRS, interference must be the WH sequence in orthogonal → x time slot/subframe.

The CSI that Figure 16 illustrates CRS, CSI-RS and pDRS estimates the typical characteristics of accuracy and the result of possibility portfolio premium.Figure 16 with regard to CRS, CSI-RS and pDRS realized MSE and compare different qualities.Based on pDRS, due to its highest MCS of low MSE(of about 0.01 demodulation needed for), optimum performance should be possible.Meanwhile, only when there are the data of particular UE, just pDRS will be sent.In addition, only pDRS will be there is on those PRB dispatching UE.

Below summarize as above in conjunction with the main purpose described in Figure 16:

■the MSE of CRS: about 0.1

■the MSE:<0.1(of aRS is desirably 0.01, depends on CDM length)

■the MSE:0.01 of pDRS ... <0.1

■>=5 CAS sizes flowed should be supported, wherein, every CAS>=4 stream (UE).

A kind of option overcoming this problem can be: have be intended to higher number PRB on scheduling UE to collect sufficient CSI information.

Contrary scheme will be: as long as possible/useful on identical PRB, just dispatch UE, make available feedback determine suitable with scheduling.Owing to typically selecting PRB by good radio channel, therefore these PRB have the inherent trend that maintenance is constant within the longer time, make the good opportunity that there is such scheduling.

The third solution combines being with using the so-called channel estimating based on the feedback of model.In this case, eNB can collect pDRS feedback within the longer time period, applies channel estimating, and all available feedback combined within the Tx time.

Require emphasis, CoMP expection for having the UE that mass data will send because otherwise, by probably can not paying off for organizing, the overall overhead of channel estimating and feedback overhead.For this reason, there is the good opportunity of following situation: on the PRB of higher number, dispatch UE, thus goodish overall CSI information is provided.

Figure 17 illustrates may distribute based on FDM and CDM to orthogonal pDRS in two subsequent subframe.Note, four arrow indicating lengths on the right half of this figure are the CDM sequence of 4.CDM has following advantage: UE need not know the number of aerial current spatial stream, and therefore eNB has and dispatches freedom completely.If UE attempts estimating the current stream do not transmitted, it only incites somebody to action not measurements interference.Meanwhile, the sequence without CDM can be used for concrete optimization, such as:

UE can decode to all available CDM sequences.When not having associated data to transmit (only transmitting pDRS), CDM sequence may be there is.These CDM sequences may be used in multi-user and multithread scheduling, estimating CQI and/or optimizing precoding weight:

-pDRS by CDM sequence extension, this CDM sequence utilize expect when overlapping PRB distributes for another UE or another stream weight and precoding.UE can report interference level or CQI based on the difference power between CDM sequence.Whether then, eNB can estimate the interference between UE or stream, feasible to find optimum MCS parameter and multi-user or multithread scheduling.

-pDRS is by CDM sequence extension, and this CDM sequence utilizes expection precoding for the weight of identical UE in next scheduling events.UE can report CSI or CQI based on the power/quality difference between existing CDM sequence and candidate CDM sequence.Then, eNB can determine whether should upgrade precoding weight.If radio channel is enough static, then searching algorithm can be used to find optimum precoding weight.

Below the subject matter relevant with the proposal expanding CDM sequence in 2 subframes is described:

■limited expense

■every CAS(Cooperative District of supporting) 4 just exchange

■for the 8Tx with 8 flow transmission, use the FDM had compared with small frequency resolution

■for the good parallel compensate of demodulation

■concerning higher flow transmission transparent UE

■hypomobility hypothesis → medium intersymbol interference.

Note, substitute CDM, FDM(code division multiplexing can also be applied) or TDM(time division multiplexing).

For the concept proposed according to the present embodiment, visible following advantage and other problems:

Main advantage is: owing to using pDRS and CSI for demodulation to estimate simultaneously, minimize RS expense.In addition, CSI estimates the PRB that expense is limited to dispatched user and uses.In addition every subband, which has limited feedback overhead, because otherwise at least will need feedback.

Due in time very sparse (CSI-RS), there is the less expense of CSI RS, but simultaneously, CSI Information Availability determines and the first precoding in the first scheduling quite accurately.Therefore, master-plan is unusual robust, even and if also allow at least medium-performance when not having pDRS to feed back.Once dispatch UE, CSI and precoding just will improve further, thus maximize attainable performance.

From standardized viewpoint, only need less change, that is, allow the feedback estimated based on pDRS, and substitute the feedback or in addition based on CSI-RS.

Based on the simulation result of SINR after CoMP, with Figure 18,19 and 20 similar, estimate overall RS expense, and found to seem for the RS of CRS+CSI-RS+pDRS realize target 15% to 20%, superperformance can be had simultaneously.Meanwhile, can feedback be kept close to the expectation upper limit of UE, nonetheless, will more careful analysis and optimization be needed, such as, for the feedback compression scheme that some are optimized.Limited RS expense can be realized, nonetheless, supposed that the UE of 80% is in CoMP pattern.

Figure 18 shows in detail SINR(signal and noise interference after attainable CoMP) for the CDF(cumulative distribution function of different CSI evaluated error (MSE)).Point curve is for the feedback delay of 5ms.As derived from Figure 18, the SIR under 50% is roughly similar with MSE.Because PMI quantizes, there are some estimator gains for larger MSE, and there are some restrictions for low-down MSE.

Figure 19 shows at CRS(dotted line), pDRS(dotted line) and both MRC combination (solid line) CoMP after SINR for 0.1 the CDF of MSE.In order to improve CSI accuracy, be applied in being averaging in 4 subsequent subframe.As derived from Figure 19, subframe can be averaging, this provide good gain.

Figure 20 shows the curve on the left half of this figure of CRS(), pDRS 0.01 MSE and both MRC when combining after CoMP SINR for 0.1 the CDF of MSE.As can be derived from Figure 20, the overall MSE that pDRS behavioral definition CSI estimates.

Note, can combination in any above-described embodiment and overall or concrete example thereof.

Below, with reference to its many aspects, multiple embodiment of the present invention is usually described.

According to the first aspect of multiple embodiment of the present invention, provide a kind of method, it comprises:

Cooperation transmission between network control unit and terminal on Resource Unit is controlled;

Detect Resource Unit and whether comprise discrete cell; And

When detecting that described Resource Unit does not comprise discrete cell, select the Resource Unit being used for described cooperation transmission.

First aspect can be modified as follows:

Described discrete cell can be reference signal.

Described method can also comprise:

Eliminate the interference caused by the transmission of reference signal in the Resource Unit do not selected for cooperation transmission.

Described elimination can in the terminal by deducting known disturbances to perform.

Described method can be performed by application precompensation by central network control unit.

According to the second aspect of multiple embodiment of the present invention, provide a kind of method, it comprises:

Resource Unit receives cooperation transmission from network control unit; And

By deducting known disturbances, eliminate the interference caused by the transmission of reference signal in the Resource Unit do not selected for described cooperation transmission.

First and second aspects can be modified as follows:

Described reference signal can be public reference signal.

Described discrete cell can be the control channel symbol used for control channel.

Described detection can be perform by detecting the number being assigned to the control channel symbol of specific sub-frame in the cell.

Described number can detect by referring to control format designator.

Can the transfer point of predetermined number for described cooperation transmission on scheduled resource unit, and described method can also comprise:

When the number of the transfer point for described cooperation transmission is less than predetermined number, applies the precompensation of transmission and/or the intertexture to transmission, and/or apply different modulating and the encoding scheme of every symbol in the transmission.

According to the third aspect of multiple embodiment of the present invention, provide a kind of equipment, it comprises:

Transmission control unit (TCU), is configured to control the cooperation transmission between network control unit and terminal on Resource Unit;

Detector, is configured to detect Resource Unit and whether comprises discrete cell; And

Selector, is configured to when detecting that described Resource Unit does not comprise discrete cell, selects the Resource Unit being used for described cooperation transmission.

The third aspect can be modified as follows:

Described discrete cell can be reference signal.

Described equipment can also comprise: eliminate unit, is configured to eliminate the interference caused by the transmission of reference signal in the Resource Unit do not selected for described cooperation transmission.

Described equipment can be configured to perform described elimination by application precompensation.

According to fourth aspect, provide a kind of equipment, it comprises:

Receiver, is configured to receive cooperation transmission from network control unit on Resource Unit; And

Controller, is configured to by deducting known disturbances, eliminates the interference caused by the transmission of public reference signal in the Resource Unit do not selected for described cooperation transmission.

Third and fourth aspect can be modified as follows:

Described reference signal can be public reference signal.

Described discrete cell can be the control channel symbol used for control channel.

Described detector can be configured to detect in the cell the number of the control channel symbol being assigned to specific sub-frame.

Described detector can be configured to by referring to control format designator to detect described number.

Can the transfer point of predetermined number for described cooperation transmission on scheduled resource unit, and described controller can be configured to when the number of the transfer point for described cooperation transmission is less than predetermined number, application to the precompensation of described transfer point and/or the intertexture to described transfer point, and/or applies different modulating and the encoding scheme of every symbol in described transfer point.

According to the 5th aspect, provide a kind of equipment, it comprises:

For the device controlled the cooperation transmission between network control unit and terminal on Resource Unit;

The device of discrete cell whether is comprised for detecting Resource Unit; And

For selecting the device for the Resource Unit of described cooperation transmission when detecting that described Resource Unit does not comprise discrete cell.

5th aspect can be modified as follows:

Described discrete cell can be reference signal.

Described equipment can also comprise: for eliminating the device of the interference caused by the transmission of reference signal in the Resource Unit do not selected for described cooperation transmission.

Described equipment can also comprise: for being performed the device of described elimination by application precompensation.

According to the 6th aspect, provide a kind of equipment, it comprises:

For receiving the device of cooperation transmission on Resource Unit from network control unit; And

For eliminating the device of the interference caused by the transmission of public reference signal in the Resource Unit do not selected for described cooperation transmission by deducting known disturbances.

5th and the 6th aspect can be modified as follows:

Described reference signal can be public reference signal.

Described discrete cell can be the control channel symbol used for control channel.

Described equipment can also comprise: for detecting the several destination devices being assigned to the control channel symbol of specific sub-frame in the cell.

Described equipment can also comprise: for by referring to control format designator to detect described several destination device.

Can the transfer point of predetermined number for described cooperation transmission on scheduled resource unit, and described equipment can also comprise: for when the number of the transfer point for described cooperation transmission is less than predetermined number, application to the precompensation of described transfer point and/or the intertexture to described transfer point, and/or applies the different modulating of every symbol and the device of encoding scheme in described transfer point.

According to the first to the 6th aspect, the Resource Unit not comprising control channel symbol used in subframe uses for the shared channel for transmitting data.

According to the first to the 6th aspect, all Resource Units can form OFDM symbol, and described control channel can be physical downlink control channel, and described shared channel can be physical down link sharing channel.

According to the 7th aspect of multiple embodiment of the present invention, provide a kind of method, it comprises:

The transmission of reference signal in the Resource Unit of Resource Block in cooperation transmission between network control unit and terminal is controlled;

Single reference signal is used for all terminals by the sequence for reference signal; And

Spatial pre-coding is carried out to the single reference signal of each terminal.

7th aspect can be modified as follows:

Described reference signal can be precoding DRS (Dedicated Reference Signal).

Described method can also comprise:

For the first reference signal in the first resource block of the sequence of described reference signal, use orthogonal reference signal.

During the transmission, in predetermined resource unit and/or predetermined resource blocks, orthogonal reference signal can be used.

Described orthogonal reference signal can be orthogonal precoding DRS (Dedicated Reference Signal).

ZF type (zero force like) precoding can be used in described cooperation transmission.

Described spatial pre-coding can be performed by Wave beam forming.

Described method can be performed by one of described network control unit or central location.

According to the eighth aspect of multiple embodiment of the present invention, provide a kind of equipment, it comprises:

Controller, is configured to control the transmission of reference signal in the Resource Unit of Resource Block in the cooperation transmission between network control unit and terminal, and for the sequence of reference signal, single reference signal is used for all terminals; And

Precoding unit, is configured to carry out spatial pre-coding to the single reference signal of each terminal.

Eighth aspect can be modified as follows:

Described reference signal can be precoding DRS (Dedicated Reference Signal).

Described controller can be configured to for the first reference signal in the first resource block of the sequence of described reference signal, uses orthogonal reference signal.

Described controller can be configured to during the transmission, in predetermined resource unit and/or predetermined resource blocks, uses orthogonal reference signal.

Described orthogonal reference signal can be orthogonal precoding DRS (Dedicated Reference Signal).

Described precoding unit can be configured in described cooperation transmission, use the precoding of ZF type.

Described precoding unit can be configured to perform described spatial pre-coding by Wave beam forming.

According to the 9th aspect of multiple embodiment of the present invention, provide a kind of equipment, it comprises:

For the device controlled the transmission of reference signal in the Resource Unit of Resource Block in the cooperation transmission between network control unit and terminal;

For the sequence for reference signal, single reference signal is used for the device of all terminals; And

For carrying out the device of spatial pre-coding to the single reference signal of each terminal.

9th aspect can be modified as follows:

Described reference signal can be precoding DRS (Dedicated Reference Signal).

Described equipment can comprise: the device using orthogonal reference signal for the first reference signal in the first resource block of the sequence for described reference signal.

Described equipment can comprise: for using the device of orthogonal reference signal during the transmission in predetermined resource unit and/or predetermined resource blocks.

Described orthogonal reference signal can be orthogonal precoding DRS (Dedicated Reference Signal).

Described equipment can comprise: for using the device of ZF type precoding in described cooperation transmission.

Described equipment can comprise: for being performed the device of described spatial pre-coding by Wave beam forming.

According to the 8th and the 9th aspect, a part for described equipment can be one of network control unit can be maybe one of network control unit, or a part for can be central location can be maybe central location.

According to the tenth aspect of multiple embodiment of the present invention, provide a kind of method, it comprises:

Orthogonal precoding DRS (Dedicated Reference Signal) is sent to terminal;

Receive channel estimated result, described channel estimation results uses precoding DRS (Dedicated Reference Signal) to estimate by described terminal; And

Channel information is determined based on the channel estimation results received.

Tenth aspect can be modified as follows:

Described orthogonal precoding DRS (Dedicated Reference Signal) can be sent to multiple terminal, can receive multiple channel estimation results, and described channel information can be determined based on multiple channel estimation results.

Described method can also comprise:

The interfere information relevant to the interference from other-end estimated based on described orthogonal precoding DRS (Dedicated Reference Signal) is received from described terminal,

Wherein, described channel information determines based on the channel estimation results received and the interfere information received.

When determining described channel information, precoding correction matrix can be calculated, and described precoding correction matrix can be used for further transmission.

In order to estimate channel status, the first channel state information reference signals can be used, further, can described orthogonal precoding DRS (Dedicated Reference Signal), receive channel estimated result be sent by repeating and determine that described channel information corrects estimated channel status.

Multiple orthogonal precoding DRS (Dedicated Reference Signal) can be sent to multiple terminal, wherein, described orthogonal precoding DRS (Dedicated Reference Signal) can distribute at least one subframe based on frequency division multiplexing and/or code division multiplexing and/or time division multiplexing.

Described method can also comprise: by using code division multiplexing, frequency division multiplexing or time division multiplexing, for precoding DRS (Dedicated Reference Signal) orthogonal described in each terminal distribution at least one subframe, described code division multiplexing, frequency division multiplexing or time division multiplexing utilize to carry out precoding when overlapped resource block distributes for the weight of other-end, or utilization will carry out precoding for the weight of same terminal in next scheduling events.

Precoding DRS (Dedicated Reference Signal) can be sent, the radio channel that detection is corresponding with Resource Unit to allow to determine for future scheduling on the current Resource Unit do not dispatched.

According to the 11 aspect of multiple embodiment of the present invention, provide a kind of method, it comprises:

Receive orthogonal precoding DRS (Dedicated Reference Signal);

Precoding DRS (Dedicated Reference Signal) is used to perform channel estimating; And

Channel estimation results is sent to network control unit.

Method according to the 11 aspect can also comprise:

The interference from other-end is estimated based on described precoding DRS (Dedicated Reference Signal); And

Interfere information is sent to described network control unit.

According to the 12 aspect of multiple embodiment of the present invention, provide a kind of equipment, it comprises:

Transmitter, is configured to orthogonal precoding DRS (Dedicated Reference Signal) to be sent to terminal;

Receiver, is configured to receive channel estimated result, and described channel estimation results uses described orthogonal precoding DRS (Dedicated Reference Signal) to estimate by described terminal; And

Controller, the channel estimation results be configured to based on receiving determines channel information.

12 aspect can be modified as follows:

Described transmitter can be configured to orthogonal precoding DRS (Dedicated Reference Signal) to be sent to multiple terminal, described receiver can be configured to receive multiple channel estimation results, and described controller can be configured to determine channel information based on described multiple channel estimation results.

Described receiver can be configured to receive from described terminal the interfere information relevant to the interference from other-end estimated based on described orthogonal precoding DRS (Dedicated Reference Signal), and described controller can be configured to determine described channel information based on the channel estimation results received and the interfere information received.

Described controller can be configured to calculate precoding correction matrix, and wherein, described precoding correction matrix may be used for further transmission.

Described controller can be configured to: in order to estimate channel status, use the first channel state information reference signals, and send described orthogonal precoding DRS (Dedicated Reference Signal), receive channel estimated result by repeating and determine that described channel information corrects estimated channel status.

Described transmitter can be configured to multiple orthogonal precoding DRS (Dedicated Reference Signal) to be sent to multiple terminal, and described controller can be configured at least one subframe, distribute described orthogonal precoding DRS (Dedicated Reference Signal) based on frequency division multiplexing and/or code division multiplexing.

Described controller can be configured to: by using code division multiplexing, frequency division multiplexing or time division multiplexing, for precoding DRS (Dedicated Reference Signal) orthogonal described in each terminal distribution at least one subframe, described code division multiplexing, frequency division multiplexing or time division multiplexing utilize to carry out precoding when overlapped resource block distributes for the weight of other-end, or utilization will carry out precoding for the weight of same terminal in next scheduling events.

Described controller can be configured to send precoding DRS (Dedicated Reference Signal) on the current Resource Unit do not dispatched, the radio channel that detection is corresponding with Resource Unit to allow to determine for future scheduling.

According to the 13 aspect of multiple embodiment of the present invention, provide a kind of equipment, it comprises:

Receiver, is configured to receive orthogonal precoding DRS (Dedicated Reference Signal);

Controller, is configured to use described orthogonal precoding DRS (Dedicated Reference Signal) to perform channel estimating; And

Transmitter, is configured to channel estimation results to be sent to network control unit.

According to the amendment of the 13 aspect, described controller can be configured to the interference estimating from least one other-end based on described orthogonal precoding DRS (Dedicated Reference Signal), and described transmitter can be configured to interfere information to be sent to described network control unit.

According to the fourteenth aspect of multiple embodiment of the present invention, provide a kind of equipment, it comprises:

For orthogonal precoding DRS (Dedicated Reference Signal) being sent to the device of terminal;

For the device of receive channel estimated result, described channel estimation results uses described orthogonal precoding DRS (Dedicated Reference Signal) to estimate by described terminal; And

For determining the device of channel information based on the channel estimation results received.

Fourteenth aspect can be modified as follows:

Described equipment can comprising device for orthogonal precoding DRS (Dedicated Reference Signal) being sent to multiple terminal, being used for receiving the device of multiple channel estimation results and being used for determining based on multiple channel estimation results the device of described channel information.

Described equipment can comprise: for receiving the device of the interfere information relevant to the interference from other-end estimated based on described orthogonal precoding DRS (Dedicated Reference Signal) from described terminal; And for determining the device of described channel information based on the channel estimation results received and the interfere information received.

Described equipment can comprise: for calculating the device of precoding correction matrix, wherein, and described precoding correction matrix may be used for further transmission.

Described equipment can comprise: in order to estimate that channel status uses the device of the first channel state information reference signals; And for sending described orthogonal precoding DRS (Dedicated Reference Signal), receive channel estimated result by repeating and determine that described channel information corrects the device of estimated channel status.

Described equipment can comprise: for multiple orthogonal precoding DRS (Dedicated Reference Signal) being sent to the device of multiple terminal; And for distributing the device of described orthogonal precoding DRS (Dedicated Reference Signal) at least one subframe based on frequency division multiplexing and/or code division multiplexing.

Described equipment can comprise: for passing through to use code division multiplexing, frequency division multiplexing or time division multiplexing at least one subframe for the device of precoding DRS (Dedicated Reference Signal) orthogonal described in each terminal distribution, described code division multiplexing, frequency division multiplexing or time division multiplexing utilize to carry out precoding when overlapped resource block distributes for the weight of other-end, or utilization will carry out precoding for the weight of same terminal in next scheduling events.

Described equipment can comprise: for sending the device of precoding DRS (Dedicated Reference Signal) radio channel that detection is corresponding with Resource Unit to allow to determine for future scheduling on the current Resource Unit do not dispatched.

According to the 15 aspect of multiple embodiment of the present invention, provide a kind of equipment, it comprises:

For receiving the device of orthogonal precoding DRS (Dedicated Reference Signal);

For using described orthogonal precoding DRS (Dedicated Reference Signal) to perform the device of channel estimating; And

For channel estimation results being sent to the device of network control unit.

According to the amendment of the 15 aspect, described equipment can comprise: for estimating the device of the interference from least one other-end based on described orthogonal precoding DRS (Dedicated Reference Signal); And for interfere information being sent to the device of described network control unit.

In as above and in amendment, described cooperation transmission can be multipoint cooperative (CoMP) transmission or multi-user's multiple-input and multiple-output (MU-MIMO) transmission etc.

According to the 16 aspect of multiple embodiment of the present invention, provide a kind of computer program, it comprises the program for treatment facility, described program comprises software code partition, performs according to the still method described in, the step any one of such scheme in above-mentioned first, fourth aspect during for running described program on described treatment facility.

According to the tenth aspect of multiple embodiment of the present invention, provide a kind of computer program, it comprises code device, perform during for running on processing unit or module according to above-mentioned first, second, method in the 7th, the tenth and the 11 or according to any one of its amendment.

Described computer program can comprise the computer-readable medium storing described software code partition.

Described program can directly be loaded in the internal storage of described treatment facility.

Should be appreciated that any one can applied separately or apply in combination with the embodiment that corresponding aspect and/or its relate in above-mentioned amendment, it does not comprise alternative unless explicitly claimed.

In order to this paper object of the present invention as above, should be noted that:

-method step is that software code has nothing to do, and any programming language that is known or following exploitation can be used to specify, as long as save the function defined by these method steps, the method step is likely implemented as software code partition and uses the processor of network control unit or end (as the example of its device, equipment and/or module, or thus as the example of entity comprising equipment and/or module) and run;

-usually, any method step can be suitable for being implemented as software or by hardware implementing, and can not change the thought of embodiment and amendment thereof in realized function aspects;

-method step and/or device, unit or device are hardware independents, and can be use the hardware technology of any known or following exploitation or these technology any mixing (such as, MOS(metal-oxide semiconductor (MOS)), CMOS(complementary MOS), the bipolar MOS of BiMOS(), BiCMOS(bipolar CMOS), ECL(emitter coupled logic), TTL(transistor-transistor logic) etc., use such as ASIC(application-specific integrated circuit (integrated circuit)) assembly, FPGA(field programmable gate array) assembly, CPLD(CPLD) assembly or DSP(digital signal processor) assembly) realize, the method step and/or device, unit or device are likely implemented as the nextport hardware component NextPort at equipment place defined above or its any module (multiple) (such as, perform the device according to the function of the equipment of embodiment as above, UE, eNode-B etc., as mentioned above),

-device, unit or device are (such as, any one in equipment defined above or its related device) may be implemented as each device, unit or device, below but this does not get rid of: they realize in systems in which in a distributed way, as long as the function of device, unit or device is retained;

Equipment can be represented by semiconductor chip, chipset or (hardware) module comprising this chip or chipset; But this does not get rid of following possibility: the function (replacement hardware implementing) of equipment or module, be implemented as the software in (software) module, such as computer program or computer program (comprising the executable software code part for performing/running on a processor);

-device can be regarded as the assembly of equipment or more than one equipment, no matter be functionally to cooperate with one another or functionally independent of one another, but is such as in identity unit shell.

Therefore, any one in above-mentioned first to the 15 aspect can be realized by the equipment comprising memory and processor, wherein, described memory store instruction, the difference in functionality/process described in described processor can be performed as above in first to the 15 by this instruction.

Note, above-described embodiment and overall and concrete example only for illustrative purposes and provide, and be never intended to make the present invention be limited to this.On the contrary, all variants and modifications that will comprise and dropping in the spirit and scope of claims are intended that.

Claims (23)

1., for a method for cooperation transmission, comprising:

Support one or more network control unit and the transmission cooperated on Resource Unit between terminal, wherein for cooperation transmission, the multiple communities controlled by described one or more network control unit form Cooperative District, and

When the described cooperation transmission on described Resource Unit when transmission of reference signals or control channel symbol, is only limited in those communities of not transmitting described reference signal or described control channel symbol on described Resource Unit by another community of described Cooperative District on Resource Unit.

2. method according to claim 1, also comprises:

Eliminate the interference caused by the transmission in a resource unit of described reference signal.

3. method according to claim 2, wherein, described elimination in the terminal or in network element by deducting known disturbances or being performed by application precompensation in central network control unit.

4. according to the method one of claims 1 to 3 Suo Shu, wherein, described restriction comprises: when discrete cell is transmitted in another community on described Resource Unit, only those communities of not transmitting described discrete cell in described Resource Unit is applied to the described cooperation transmission in described Resource Unit.

5. method according to claim 1, also comprises the number detecting in the cell and be assigned to the control channel symbol of specific sub-frame.

6. method according to claim 5, wherein, described number detects by referring to control format designator.

7. the method according to any one of claim 1,5 and 6, wherein, the transfer point of the predetermined number for described cooperation transmission on scheduled resource unit, described method also comprises:

When the number of the transfer point for described cooperation transmission is less than predetermined number, applies the precompensation of transmission and/or the intertexture to transmission, and/or apply different modulating and the encoding scheme of every symbol in the transmission.

8. the method according to any one of claim 1,5 and 6, wherein, uses for the shared channel for transmitting data not comprising the Resource Unit used in the subframe of control channel symbol.

9. method according to claim 8, wherein, described Resource Unit forms OFDM symbol, and described control channel is physical downlink control channel, and described shared channel is physical down link sharing channel.

10. the method according to any one of claim 1,5 and 6, wherein, described cooperation transmission is multipoint cooperative (CoMP) transmission or multi-user's multiple-input and multiple-output (MU-MIMO) transmission.

11. 1 kinds, for the method for cooperation transmission, comprising:

On the Resource Unit cooperated by one or more network control unit, receive transmission in one cell, wherein for cooperation transmission, the multiple communities controlled by described one or more network control unit form Cooperative District, and wherein, when the described cooperation transmission on described Resource Unit when transmission of reference signals or the control channel symbol for control channel, is only limited in those communities of not transmitting described reference signal or described control channel symbol on described Resource Unit by another community of described Cooperative District on Resource Unit; And

Eliminate or alleviate by described reference signal or the interference that causes for the transmission of the described control channel symbol of control channel.

12. 1 kinds, for the equipment of cooperation transmission, comprising:

Transmission control unit (TCU), is configured to support one or more network control unit and the transmission cooperated on Resource Unit between terminal, wherein for cooperation transmission, the multiple communities controlled by described one or more network control unit form Cooperative District; And

Selector, be configured to when the described cooperation transmission on described Resource Unit when transmission of reference signals or control channel symbol, is only limited in those communities of not transmitting described reference signal or described control channel symbol on described Resource Unit by another community of described Cooperative District on Resource Unit.

13. equipment according to claim 12, also comprise:

Eliminate unit, be configured to eliminate the interference caused by reference signal transmission in a resource unit.

14. equipment according to claim 13, wherein, described equipment is configured to perform described elimination by application precompensation.

15. equipment according to claim 12, wherein, described detector is configured to detect in the cell the number of the control channel symbol being assigned to specific sub-frame.

16. equipment according to claim 15, wherein, described detector is configured to by referring to control format designator to detect described number.

17. according to claim 12 to the equipment one of 16 described, wherein, and the transfer point of the predetermined number for described cooperation transmission on scheduled resource unit,

Wherein, described controller is also configured to when the number of the transfer point for described cooperation transmission is less than predetermined number, application to the precompensation of described transfer point and/or the intertexture to described transfer point, and/or applies different modulating and the encoding scheme of every symbol in described transfer point.

18. according to claim 12 to the equipment one of 16 described, wherein, uses not comprising the Resource Unit used in the subframe of control channel symbol for the shared channel for transmitting data.

19. equipment according to claim 18, wherein, described Resource Unit forms OFDM symbol, and described control channel is physical downlink control channel, and described shared channel is physical down link sharing channel.

20. according to claim 12 to the equipment one of 16 described, and wherein, described cooperation transmission is multipoint cooperative (CoMP) transmission or multi-user's multiple-input and multiple-output (MU-MIMO) transmission.

21. 1 kinds, for the equipment of cooperation transmission, comprising:

Receiver, be configured on the Resource Unit cooperated by one or more network control unit, receive transmission in one cell, wherein for cooperation transmission, the multiple communities controlled by described network control unit form Cooperative District, and wherein, when the described cooperation transmission on described Resource Unit when transmission of reference signals or the control channel symbol for control channel, is only limited in those communities of not transmitting described reference signal or described control channel symbol on described Resource Unit by another community of described Cooperative District on Resource Unit; And

Controller, is configured to eliminate or alleviate by described reference signal or the interference that causes for the transmission of the described control channel symbol of control channel.

22. 1 kinds, for the equipment of cooperation transmission, comprising:

For supporting the device of one or more network control unit and the transmission cooperated on Resource Unit between terminal, wherein for cooperation transmission, the multiple communities controlled by described one or more network control unit form Cooperative District; And

On Resource Unit, when transmission of reference signals or control channel symbol, the described cooperation transmission on described Resource Unit is only limited in the device of those communities of not transmitting described reference signal or described control channel symbol on described Resource Unit for another community when described Cooperative District.

23. 1 kinds, for the equipment of cooperation transmission, comprising:

Be provided on the Resource Unit cooperated by one or more network control unit, receive the device of transmission in one cell, wherein for cooperation transmission, the multiple communities controlled by described one or more network control unit form Cooperative District, and wherein, when the described cooperation transmission on described Resource Unit when transmission of reference signals or the control channel symbol for control channel, is only limited in those communities of not transmitting described reference signal or described control channel symbol on described Resource Unit by another community of described Cooperative District on Resource Unit; And

For eliminating or alleviating by described reference signal or the device of interference that causes for the transmission of the described control channel symbol of control channel.