CN103959671A

CN103959671A - Method and apparatus for transmitting and receiving signal in distributed antenna system

Info

Publication number: CN103959671A
Application number: CN201280058009.7A
Authority: CN
Inventors: 金润善; 李晓镇; 赵俊暎; 金起日; 李周镐
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2011-09-30
Filing date: 2012-09-28
Publication date: 2014-07-30
Anticipated expiration: 2032-09-28
Also published as: CN103959671B; KR20130035830A; RU2014117706A; JP2014535188A; JP6433788B2; AU2012316918B2; RU2597219C2; IN2014KN00907A; AU2012316918A1

Abstract

An apparatus and method for transmitting and receiving a signal in a Distributed Antenna System (DAS) is provided. A method for determining an initial state in a DAS includes receiving a value through high-level signalling and determining an initial state based on the value, in which the value includes a value in which is set an initial state of a scrambling sequence, which differs according to a transmission point.

Description

For method and device at distributing antenna system sending and receiving signal

Technical field

Relate generally to mobile radio system of the present invention, and more specifically, relate to for the device and method at distributing antenna system (DAS) sending and receiving signal.

Background technology

Conventionally, build cellular radio mobile communication system by set up multiple communities in finite region.Base station (BS) parts of being responsible for mobile communication in each community are positioned at the center of community.BS parts can be antenna or the signal processings for sending wireless signal, and provide Mobile Communication Service at center of housing estate to the subscriber equipment (UE) in community.Thereby the system fixing up an aerial wire at center of housing estate is called centralized antenna system (CAS), and common mobile communication system is the example of such system.

Also there is the distributing antenna system (DAS) different from CAS.

Summary of the invention

Technical problem

But compared with CAS, traditional DAS needs can be by making antenna distribute equably the scheme of the Mobile Communication Service that improvement is provided on the service coverage area of community.

Technical scheme

Therefore, the invention provides in the DAS on a kind of service coverage area that is disposed in each BS at antenna with distribution mode and be identified for the initial condition of the scramble sequence that generates demodulated reference signal (DMRS) for the method for efficient communication.

According to an aspect of the present invention, provide a kind of for determine the method for initial condition at DAS, described method comprises: be worth by high-level signaling reception; And determine initial condition based on this value, and the instruction of this value is configured to the value of the initial condition of scramble sequence, and it is according to transfer point and difference.

According to a further aspect of the invention, provide a kind of for determine the device of initial condition at DAS, this device comprises: receiver, for being worth by high-level signaling reception; And controller, for determining initial condition based on this value, this value comprises other value that is configured to the initial condition with scramble sequence, it is according to transfer point and difference.

According to a further aspect of the invention, provide a kind of for determine the method for initial condition at DAS, the method comprises: receive scrambled code mark (SCID); And SCID based on received judges that determined initial condition leaves over initial condition or new initial condition.

According to a further aspect of the invention, provide a kind of for determine the device of initial condition at DAS, this device comprises: receiver, for receiving SCID; And controller, judge that for the SCID based on received determined initial condition leaves over initial condition or new initial condition.

Brief description of the drawings

The detailed description of carrying out below in conjunction with accompanying drawing, above-mentioned and further feature and the advantage of various embodiments of the present invention will be clearer, in the accompanying drawings:

Fig. 1 illustrates the multiple communities in legacy system;

Fig. 2 illustrates the downlink resource blocks (RB) of senior Long Term Evolution (LTE-A) system;

Fig. 3 illustrates the resource element (RE) that has wherein sent 1 port channel state information reference signals (CSI-RS), 2 port CSI-RS, 4 port CSI-RS and 8 port CSI-RS;

Fig. 4 illustrates the multiple transfer points in DAS;

Fig. 5 illustrates the down link control information (DCI) sending via physical downlink control channel (PDCCH) according to an embodiment of the invention;

Fig. 6 illustrates the operation of BS according to an embodiment of the invention;

Fig. 7 illustrates the operation of UE according to an embodiment of the invention; And

Fig. 8 illustrates the relation between the PDCCH (E-PDCCH) and the physical down link sharing channel (PDSCH) that strengthen.

Embodiment

Hereinafter, describe with reference to the accompanying drawings embodiments of the invention in detail.If unnecessarily fuzzy theme of the present invention of known function and structure, will not be described them.The function of the term here using based in the present invention defines, and can change according to user, operator's intention or enforcement.Therefore, the definition of described term should be made based on running through the content of specification.

To the detailed description of various embodiments of the present invention will be mainly based on taking Orthodoxy Frequency Division Multiplex (OFDM) as basic wireless communication system, particularly third generation partner program (3GPP) strengthen general land wireless access (EUTRA) standard and make, but those of ordinary skill in the art will be understood that, theme of the present invention can be applicable to have other communication system of similar technical background and channel form, and can not depart from the scope of the present invention widely.

The antenna that the invention discloses a kind of operation of each BS therein in the mobile communication system that has multiple BS is distributed in the DAS on the service coverage area of BS, in UE, carry out the method for interferometry for the efficient communication in down link.

From provide towards the communication service of voice in early days, mobile communication system has developed into the wireless packet data communication system of the high-speed high-quality amount for data and multimedia service are provided now.Recently, various mobile communication standards (such as the HRPD (high rate packet data) (HRPD) of the high-speed downlink packet access (HSDPA) of 3GPP, High Speed Uplink Packet access (HSUPA), LTE, LTE-A, 3GPP2 and IEEE (IEEE) 802.16) developed into the wireless block data transmission service of supporting high-speed high-quality amount.Specifically, developed and be used for effectively supporting the LTE system of high-speed radio packet data transmission by utilizing various wireless connect technologies that wireless system capacity is maximized.Compared with LTE system, from LTE System Development and come LTE-A system improved data transmission capacity.

BS and UE parts that LTE general reference is corresponding with the system version 8 or 9 of 3GPP normal structure, and LTE-A general reference BS and the UE parts corresponding with the system version 10 of 3GPP normal structure.3GPP normal structure is by LTE-A system standardization and now develop and have the standardization of carrying high performance system version subsequently based on standardization LTE-A system.

Existing the 3rd generation and the 4th generation wireless packet data communication system (such as HSDPA, HSUPA, HRPD, LTE/LTE-A) use adaptive modulation and coding (AMC) scheme and the sensitive scheduling scheme of channel to improve efficiency of transmission.In the time utilizing AMC scheme, the amount of the data that transmitter can will send according to channel status adjustment.,, in the time that channel status is poor, transmitter reduces the amount of the data that will send so that reception error probability is matched to aspiration level.In the time that channel status is good, the amount of the data that transmitter increase will send is to match reception error probability aspiration level and to send efficiently much information.In the time utilizing the sensitive scheduling resource Managed Solution of channel, because transmitter optionally offers service the user among multiple users with fabulous channel status, so compared with channel allocation being provided to service after to user, increased power system capacity with transmitter.This capacity increase is commonly called multi-user diversity gain.AMC scheme and the channel sensitive scheduling scheme impaction of partial channel state information for just feeding back from receiver in the most efficient time reception, and apply suitable modulation and coding techniques.

In the time using together with multiple-input and multiple-output (MIMO) transmission plan, AMC scheme can be determined the quantity of space layer or the grade of signal transmission (rank).AMC scheme is also determined best data rate and is utilized MIMO and code rate and modulation scheme are considered the quantity of the layer for transmitting.

Carrying out substituting as the broad research of the CDMA of the multiple access scheme using in the second generation and 3-G (Generation Three mobile communication system) using the OFDMA of next generation mobile communication system.3GPP and 3GPP2 have started the standardization effort to the evolution system based on OFDMA.Estimate that OFDMA will increase capacity compared with CDMA, this is because can carry out frequency domain dispatching on frequency axis.Although can utilize the dispatching method that channel is sensitive to obtain capacity gain from the time dependent characteristic of channel, can utilize with the characteristic of channel of frequency change and obtain larger capacity gain.

Conventionally, set up the mobile communications network being formed by multiple communities to expand the power system capacity in mobile communication system.Determine the size of each community according to the through-put power of community.

Fig. 1 illustrates multiple communities of arranging in legacy system.

In Fig. 1, the transfer point 100 of utilizing high transmitted power to carry out transmission forms has large-area community, forms the community with small size and utilize low transmitted power to carry out the transfer point 110,120,130 and 140 sending in the cell area of transfer point 100.In Fig. 1, transfer point 100,110,120,130 and 140 is by utilizing individual antenna or multiple antenna in their position to carry out sending and receiving wireless signal, thus to they separately the UE in community Mobile Communication Service is provided.The transfer point 150 of utilizing high transmitted power to carry out transmission forms has large-area another community, and the transfer point 160,170,180 and 190 of utilizing low transmitted power to carry out transmission forms the community with small size in the cell area of transfer point 150.Form respectively 10Ge community by transfer point 100,110,120,130,140,150,160,170,180 and 190 and there is unique community ID.This community ID distributes to each community to allow UE to identify the value of this community, and in LTE/LTE-A system, supports 500 or more community ID.

In Fig. 1, the signal being sent by each community can utilize respective cell ID differently to send.Specifically, for the demodulated reference signal (DMRS) of carrying out the PDSCH of the down link of channel estimating for UE in LTE-A system, differently apply the randomized scramble sequence being employed for signal according to community ID.It is the reference signal that is sent to enable to carry out for PDSCH the channel estimating of channel reconstructing by eNB to UE for the DMRS (or PDSCH DMRS) of PDSCH.

In LTE-A system, utilize OFDMA scheme signal transmission.For being divided into multiple Resource Block (RB) in the bandwidth of LTE-A system signal transmission, and UE can receive service signal by one or more RB.Fig. 2 illustrates the down link RB of LTE-A system.A RB is made up of 12 subcarriers in frequency domain, and is made up of 14 OFDM code elements on time shaft.Frequency and the time resource that in a RB, can carry in the minimum unit of data are called as resource element (RE), and RB is made up of 168 (12 subcarrier × 14 OFDM code elements) individual RE.

In a RB, the specific reference signal of signal and community (CRS), demodulated reference signal (DMRS), physical down link sharing channel (PDSCH) and the control channel of difference in functionality carried out in transmission, as shown in Figure 2.In addition, can transmitting channel state information reference signal (CSI-RS) in the 200-219 of the position of Fig. 2.In one or more positions in the 200-219 of position, can transmit CSI-RS, and do not transmit PDSCH in the position of transmission CSI-RS, but as an alternative, can among the 200-219 of position, not be arranged in the position of CSI-RS and transmit PDSCH.

Fig. 3 diagram is wherein transmitted the resource element (RE) of 1 port channel state information reference signals (CSI-RS), 2 port CSI-RS, 4 port CSI-RS and 8 port CSI-RS.As seen from Figure 3,1 port CSI-RS and 2 port CSI-RS have the sub-style properties in the transmission location that its transmission location is included in 4 port CSI-RS.4 port CSI-RS have the sub-style properties in the transmission location that its transmission location is included in 8 port CSI-RS.The transmission location 320 that for example, can transmit 4 port CSI-RS is included in the transmission location 330 that can transmit 8 port CSI-RS.

In the time having multiple communities of different districts ID and exist as illustrated in fig. 1, different scramblings is applied to the PDSCH DMRS of Fig. 2 according to community ID.By applying different scramblings, the interference generating between the PDSCH DMRS sending from different districts is by randomization effectively, thus raising channel estimating performance.More specifically, utilize the initial condition being provided by equation (1) to generate the scramble sequence that is applied to each community, wherein:

Mathematical expression 1

Usually, generate scramble sequence according to generator polynomial, and its value changes according to the initial condition arranging in the time that scramble sequence generates.In equation (1), represent community ID and have according to the variable value of community ID.Therefore, there is ID community, different districts and there is different initial conditions, thus can be by different scramble sequence scrambling PDSCH DMRS.

In the time setting up as the DAS of advanced mobile communication system, the function of carrying out scrambling in the different districts in LTE-A system as above is restricted aspect the randomization of disturbing.This is because in DAS, similar with legacy system, and transmitter and receiver are disposed on the point of distribution so that Mobile Communication Service to be provided, but in each transfer point, do not have unique community ID, but multiple transfer points are shared Yi Ge community ID.

Fig. 4 illustrates the multiple transfer points that form DAS.In Fig. 4, utilize high transmitted power carry out the transfer point 400 of transmission and utilize low transmitted power to carry out the transfer point 410,420,430 and 440 of transmitting and all share Yi Ge community ID.Thereby compared with traditional mobile communication as shown in Figure 1, the DAS being shared by multiple transfer points for one of them community ID, can carry out the distribution of the Radio Resource of multiple transfer points of a UE efficiently.

For DAS as shown in Figure 4, multiple transfer points are shared Yi Ge community ID, thereby when utilize the PDSCH DMRS scrambling defining in current LTE-A system time, all transfer points are used the scramble sequence generating based on identical initial condition, thereby can not realize effective interference randomization.; in Fig. 4; be set to by community ID PDSCH DMRS that 0 transfer point sends and can Yu Youqi community ID be set to the PDSCH DMRS that 1 transfer point sends and obtain mutually effective interference randomization effect, but can not obtain identical effect between the transfer point with same cells ID.

Therefore, the invention discloses for the required initial condition of the scramble sequence of distributively generated PDSCH DMRS rightly to exist therein the DAS of multiple transfer points of sharing same cells ID to realize the method for effective interference randomization.

As previously mentioned, the conventional art of DAS, for the PDSCH DMRS transmitting in down link, determines the initial condition of scramble sequence, thereby can not obtain interference randomization effect between the transfer point with same cells ID according to community ID.In order to address this problem, the initial condition of different scrambling sequence need to be set for the different transfer points in same cells.In the present invention, some essential condition of the new initial condition of applying scramble sequence will be provided for as follows.

Condition 1: in DAS, each transfer point must be used scramble sequence based on new initial condition.

Condition 2: in DAS, each transfer point must be based on leaving over initial condition and new initial condition use scramble sequence.

Condition 3: according to determining of network, leaving between initial condition and new initial condition, dynamically change must be possible.

Condition 1 is required to effectively carrying out interference randomization in supporting the transmission of UE of DAS.Condition 2 be carry out in same time and frequency resource to not supporting that the multiuser MIMO (MU-MIMO) of transmission of the UE of DAS and the UE of support DAS is required.Do not support leaving over UE and can not supporting the scramble sequence based on disclosed new initial condition in the present invention of DAS.In order to transmit by utilize multiple antennas to carry out in same time and frequency resource to the MU-MIMO of the UE that leaves over the new initial condition of UE and support simultaneously, must utilize the scramble sequence based on leaving over initial condition to send PDSCH DMRS, even if realize interference randomization also so unsuccessfully.

Condition 3 is important, and this is because can carry out transmission for the UE that supports DAS, or can be according to determining of scheduler and for supporting the UE of DAS and only support the UE of conventional art both to carry out transmission in each transfer point.,, in specific time period, in the time proceeding to the transmission of UE of the scramble sequence of supporting the initial condition based on new, utilize the scramble sequence of the initial condition based on new to carry out scrambling DMRS.But, in another period, for the UE that leaves over that does not support DAS, utilize the scramble sequence based on leaving over initial condition to carry out scrambling PDSCH DMRS.With similar when the scramble sequence of each transfer point support based on leaving over the scramble sequence of initial condition and the initial condition based on new, support the UE of DAS must support described two scramble sequence both.

In order to utilize the scramble sequence of the initial condition based on new, need to determine initial condition in mode shared between UE and eNB.In the present invention, as the method for determining new initial condition, multiple methods of LTE-A system will openly be can be applicable to below.Hereinafter, will the method 1 to 6 of the new initial condition for being identified for PDSCH DMRS be disclosed.

method 1: for determining according to the quantity of the position of CSI-RS port one 5 and CSI-RS port the method of initial condition

CSI-RS is the reference signal that UE is used for measuring the channel of the down link in LTE-A.In LTE-A system, CSI-RS is corresponding to port one 5 to 22.Table 1 shows the position of CSI-RS port one 5 possible in LTE-A system and the quantity of CSI-RS port., table 1 shows the position about the CSI-RS port one 5 of the quantity of the CSI-RS port of the normal cyclic prefix subframe of LTE-A system.

Table 1

As can be drawn from Table 1, in the time that CSI-RS has port number 1,2,4,8, the position of 20,20,10 and 5 port ones 5 is possible respectively.Usually, be arranged in in-plant transfer point and send CSI-RS at diverse location, in order to avoid disturb.Thereby, by utilizing the feature that the CSI-RS of diverse location is set in the transfer point in closely, can in following equation (2)-(5), be identified for the initial condition of the scramble sequence of the PDSCH DMRS in DAS.

Mathematical expression 2

In the time that 1 port CSI-RS is arranged as follows:

Mathematical expression 3

In the time that 2 port CSI-RS are arranged as follows:

Mathematical expression 4

In the time that 4 port CSI-RS are arranged as follows:

Mathematical expression 5

In the time that 8 port CSI-RS are arranged as follows:

Wherein, 1 port CSI-RS and 2 port CSI-RS have the CSI-RS port of equal number.In this case, identical initial condition is set, but not independent initial condition.

Use equation given below (6) for determine the other method of new initial condition according to the quantity of the position of CSI-RS port one 5 and CSI-RS port.

Mathematical expression 6

Wherein, i have as in table 2 according to the value that quantity provided of CSI-RS port.Table 2 show in equation (6) according to the quantity i of CSI-RS port.

Table 2

The method that is provided for the initial condition of the new scramble sequence of PDSCH DMRS based on equation (6) is by considering that all sidedly quantity and position that CSI-RS port is possible determine initial condition.Compared with equation (2)-(5), this method is favourable on the still less position that changes initial condition.The method that is identified for the initial condition of PDSCH DMRS based on equation (6) also can be as in equation (2)-(5), for 1 port CSI-RS and 2 port CSI-RS, identical initial condition is set, but not independent initial condition.

method 2: for determine the method for initial condition according to the position of CSI-RS port one 5

According to the position of CSI-RS port one 5, can in following equation (7), be identified for the initial condition of the new scramble sequence of PDSCH DMRS:

Mathematical expression 7

Wherein, i value can be determined according to the position of CSI-RS port one 5 possible in LTE-A system as shown in table 3.

Table 3

Position	I value
		200 of Fig. 2	0
201 of Fig. 2	1
		202 of Fig. 2	2
203 of Fig. 2	3
		204 of Fig. 2	4
205 of Fig. 2	5
		206 of Fig. 2	6
207 of Fig. 2	7
		208 of Fig. 2	8
209 of Fig. 2	9

210 of Fig. 2	10
		211 of Fig. 2	11
212 of Fig. 2	12
		213 of Fig. 2	13
214 of Fig. 2	14
		215 of Fig. 2	15
216 of Fig. 2	16
		217 of Fig. 2	17
218 of Fig. 2	18
		219 of Fig. 2	19

method 3: at the beginning of determining according to the 8 port CSI-RS patterns that comprise transmission CSI-RS pattern the method of beginning state

In LTE-A system, 1 port CSI-RS, 2 port CSI-RS and 4 port CSI-RS are all the increment formulas of 8 port CSI-RS, as shown in Figure 3., the transmission location of 1 port CSI-RS, 2 port CSI-RS and 4 port CSI-RS is included in the transmission location of specific 8 port CSI-RS.By utilizing this feature, the increment formula that can be 8 port CSI-RS based on its corresponding CSI-RS is identified for the initial condition of the new scramble sequence of PDSCH DMRS.Table 4 illustrates according to the i value of that the 8 port CSI-RS that has comprised corresponding CSI-RS based on following equation (8).

Mathematical expression 8

Table 4

When the initial condition of the new scramble sequence for PDSCH DMRS be according to equation (8) and table 4 definite time, all CSI-RS that are included in 8 identical port CSI-RS have identical initial condition.

method 4: for according to comprise transmission CSI-RS pattern 8 port CSI-RS patterns relatively the method of initial condition is determined in position

As shown in Figure 3, the CSI-RS of LTE-A system is designed to have ad hoc rules.For example, Fig. 3 for transmitting having with respect to the identical relative position of 8 port CSI-RS that comprises corresponding 2 port CSI-RS for transmitting the transmission location 304 of another 2 port CSI-RS of the transmission location 300 of 2 port CSI-RS and Fig. 3., the transmission location 300 of Fig. 3 is identical with respect to the relative position of transmission location 330 and the transmission location of Fig. 3 304 of 8 port CSI-RS with respect to the relative position of the transmission location 331 of 8 port CSI-RS.Can utilize the initial condition that is identified for the new scramble sequence of PDSCH DMRS with respect to the relative position of 8 port CSI-RS, as shown in Table 5 below, table 5 shows the i value with respect to the relative transmission location in port CSI-RS transmission location, and is equation (9) based on below.

Mathematical expression 9

Table 5

In said method, also consider that the quantity of CSI-RS port arranges i value.Also can only consider that the relative position of port one 5 is identified for the initial condition of the new scramble sequence of PDSCH DMRS, as shown in Table 6 below, table 6 shows according to the i value of the relative transmission location of the port one 5 in port CSI-RS transmission location, and is equation (10) based on below.

Mathematical expression 10

represent physical-layer cell identity, n _sCIDthe quantity that represents scrambled code mark, i value is set to the quantity of CSI-RS port, n _srepresent the timeslot number in radio frames.

Table 6

When determine the initial condition of the scramble sequence for PDSCH DMRS configuring according to CSI-RS as in method 1-4 time, if be provided with multiple CSI-RS, can determine according to multiple initial conditions.

method 5: for determine the method for initial condition according to high-level signaling

In method 1-4, according to the new initial condition that the scramble sequence that is provided for PDSCH DMRS is set of CSI-RS.Such method is in the case of needing extra signaling between eNB and UE but realize target carrying out according to rule, thereby is difficult to carry out optimization according to situation.In order to overcome such shortcoming, which initial condition eNB can will use to UE notice by independent high-level signaling.In this case, eNB can notify the whole or a part of of the information corresponding with initial condition to UE.Usually because previously determining a part for initial condition, so can be in the situation that need not additionally notifying use value, and eNB can be only to UE notice remainder.The new initial condition of the scramble sequence of PDSCH DMRS for example, is provided as provided in equation (11).

Mathematical expression 11

Wherein, can determine by independent process therefore, eNB can be only in UE notice equation (11) for utilizing the disclosed high-level signaling of the present invention to carry out the definite i of initial condition.In equation (11), when i is in the time that 0 arrives in the scope of K-1, initial condition can be to pass through altogether the information that express individual position.

Can utilize equation (12) and the equation (11) of method 5 to determine initial condition.

Mathematical expression 12

Visible in equation (12), when compared with equation (11), substituted by X.In equation (12), X has the amount of information of 9 and is utilized high-level signaling and notifies to UE.In traditional LTE/LTE-A system, for the initial condition of DMRS the value of being determined by following UE: this UE receives the synchronizing channel for main synchronizing signal (PSS) and less important synchronizing signal (SSS) in the situation that of high-level signaling separately.In the present invention, disclosed equation (12) is determined initial condition by high-level signaling to X and the i of UE notice based on eNB, but not utilizes PSS and SSS to determine when profit is in this way time, can in the middle of the initial condition than many equation (11), select.

Except determining the method for initial condition based on X and i as in equation (12), also can only utilize X to determine initial condition.This is with identical in the time that i is fixed as ' 0 ' always.This method allows leaving over reusing of the initial condition for DMRS that defines in LTE/LTE-A, and this has reduced the complexity of implementation.By this way, in the time only utilizing X to determine initial condition, which initial condition eNB will use by the high-level signaling with X to UE notice.

method 6: for determine the method for initial condition according to the RNTI of UE

Method 5 is by utilizing independent high-level signaling to determine new initial condition.In the time of the method 5 of utilization, due to high-level signaling, overhead is inevitable.A mode avoiding expense is that the radio network temporary identifier (RNTI) by utilizing each UE to have is determined initial condition.RNTI is used to identify UE, and in network, sends in the time that UE is connected in LTE/LTE-A system, and no matter whether UE carries out coordinated multipoint transmission (CoMP) sending and receiving.By the RNTI substantially providing is provided, the extra high-level signaling as in method 5 is unnecessary.For by utilizing RNTI to determine new initial condition, can use equation (13) or equation (14) below.

Mathematical expression 13

Mathematical expression 14

In equation (14), G is greater than 1 integer.

Method 1-6 is used for the initial condition of the new scramble sequence that is identified for PDSCH DMRS.As previously mentioned, in the time of each transfer point scrambling PDSCH DMRS in DAS, there are several conditions that will be satisfied.Method 1-5 determines 1 the new initial condition of satisfying condition.The scramble sequence that in addition, the scrambling of PDSCH DMRS need to suitably be used the scramble sequence by leaving over initial condition generation and be generated by the new initial condition of being determined by method 1-6 according to situation., leaving over initial condition and new initial condition need to determine and change along with the scheduling for each subframe.

Which for this function, the invention discloses for notifying initial condition to be used to the method to DMRS scrambling via the PDCCH of LTE system.For this reason, when information ' CoMP scrambling index ' is newly added to PDCCH and each eNB to UE allocation of downlink Radio Resource, this information is sent out for notice.Can carry out transmission information ' CoMP scrambling index ' via PDCCH, but also can notify in the same manner it as the PDCCH (E-PDCCH) of the enhancing of the improvement channel of PDCCH by utilization.

Table 7 relates to for notify which initial condition by the first embodiment being used to PDSCH DMRS scrambling via PDCCH.

Table 7

CoMP scrambling index	For the initial condition of DMRS scrambling
		00	Leave over initial condition
01	New initial condition 1
		10	New initial condition 2
11	New initial condition 3

Table 7 shows multiple new initial conditions, is possible because utilize the cooperation transmission of multiple transfer points in DAS.In the time utilizing cooperation transmission, according to determining of central controller, for each subframe, UE can receive the downlink transmission in any one in multiple transfer points and can receive the downlink transmission in multiple transfer points according to situation.

In table 7, leave over initial condition and new initial condition can have identical community ID, but also can there is different community ID to allow the cooperation transmission between the transfer point with same cells ID and the transfer point of neighbor cell in DAS.

In table 7, before the notice via PDCCH, utilize the present invention in one of disclosed method 1-6 determine new initial condition.In method 1-4, arrange and determine initial condition according to the CSI-RS that is set to UE, and in method 5, determine initial condition by independent high-level signaling.In method 6, determine initial condition by the RNTI of UE.

Table 8 relates to for notify which initial condition by the second embodiment being used to PDSCH DMRS scrambling via PDCCH.

Table 8

CoMP scrambling index	For the initial condition of DMRS scrambling
		00	Leave over initial condition 1
01	Leave over initial condition 2
		10	New initial condition 1
11	New initial condition 2

In table 8, there are multiple initial condition and multiple new initial conditions left over.Because it is possible utilizing the cooperation transmission of multiple transfer points in DAS, so there are multiple new initial conditions, also allow the cooperation transmission between the neighbor cell of not setting up with spaced antenna form.In table 7 and table 8, multiple initial conditions can comprise that at least one leaves over initial condition.The present invention allows UE to use new initial condition simultaneously and leaves over initial condition.In the same way, only can use new initial condition.In table 7 and table 8, all initial conditions of leaving over are substituted or are removed by new initial condition.

Can utilize 2 initial condition notices of carrying out the scramble sequence for PDSCH DMRS via PDCCH disclosed by the invention, in above-described embodiment.By utilizing extra position, also can notify extra initial condition.Leave over which in initial condition and new initial condition by utilizing 1, can notify to use.The community ID of the Serving cell that can implicitly be connected to according to UE in the foregoing description, determines the high-level signaling of leaving over initial condition and need not be independent.In aforesaid way, also can utilize independent high-level signaling to determine initial condition.

To utilize CoMP scrambling index that traditional LTE-A system defines and the combination of scrambled code mark (SCID) for will use the other method of which initial condition to UE notice.Table 9 relates to for notify which initial condition by the 3rd embodiment being used to PDSCH DMRS scrambling via PDCCH.

Table 9

CoMP scrambling index	SCID	For the initial condition of DMRS scrambling
			0	0	Leave over initial condition
0	1	New initial condition 1
			1	0	New initial condition 2
1	1	New initial condition 3

Leave over the least significant bit (LSB) that the SCID defining in LTE-A is only identified for the initial condition of the scrambling of DMRS.But in the time utilizing in the present invention disclosed method, SCID can combine to determine other with CoMP scrambling index and for the LSB of the initial condition of the scrambling of DMRS.,, in table 9, CoMP scrambling index and SCID determine by one of determined multiple initial conditions of method 1-6, but not leave over only 1 LSB of definite initial condition of SCID.Multiple initial conditions of being determined by said method really can be different on multiple positions.,, in the time using together the CoMP scrambling index of table 9 and SCID, SCID can not determine the LSB of 1 as in conventional art.Method 1-6 is used to determine which initial condition the combined information of CoMP scrambling index and SCID specifies.

Table 10 relates to for notify which initial condition by the 4th embodiment being used to PDSCH DMRS scrambling via PDCCH.

Table 10

CoMP scrambling index	SCID	For the initial condition of DMRS scrambling
			00	0	Leave over initial condition 1
00	1	Leave over initial condition 2
			01	0	New initial condition 1
01	1	New initial condition 2
			10	0	New initial condition 3
10	1	New initial condition 4
			11	0	New initial condition 5
11	1	New initial condition 6

In LTE-A, SCID has the amount of information of 1, but its with DMRS port assignment information combination after be just sent out.In this case, only have in the time that the quantity of the DMRS port distributing is 1 or 2, SCID can be ' 0 ' or ' 1 ', and in the time that the quantity of the DMRS port distributing is 3 or more, SCID is fixed to ' 0 '.When use the combination of CoMP scrambling index and SCID as in table 9 and table 10 time, the initial condition that is used for the scramble sequence of DMRS can be different initial condition, and different from conventional art, even if distributed 3 or more DMRS port, also can divide the initial condition of the scramble sequence that is used in DMRS.

Even in the time having distributed three or more DMRS ports, by distributing different initial conditions, the interference randomization between transfer point is also possible in DAS., in the time only utilizing SCID, if distributed three or more DMRS ports, SCID always has ' 0 ' value, thereby uses fixing initial condition.But, when utilize in the present invention disclosed CoMP scrambling index together with SCID time, in table 9 and table 10, even if SCID is ' 0 ', also can distribute different initial conditions.Such advantage is also applicable to disclosed method in table 7 and table 8.

Fig. 5 illustrates according to the DCI via PDCCH transmission of the present invention.

In Fig. 5, via PDCCH, together with the information 520 that in the present invention, disclosed CoMP scrambling index 500 is relevant with other DCI to SCID510, transmit.By utilizing CoMP scrambling index 500, UE can identify the initial condition based on its generation and use scramble sequence, as mentioned above.In Fig. 5, SCID510 is 1 information and leaving in LTE/LTE-A system definition to allow the MU-MIMO in a transfer point.This value is included in equation (1) in (10).Except the transmission of the SCID510 as 1 information, SCID510 also can be with DMRS port assignment information combination for transmission., UE can utilize one of method 1-6 to determine new initial condition before the CoMP scrambling index 500 of reception Fig. 5 and SCID510.Afterwards, UE receives the information of Fig. 5 from eNB via PDCCH, thereby notified which initial condition is used to the scrambling to DMRS.

Fig. 6 illustrates according to following process of the present invention: the initial condition and the eNB that are identified for the new scramble sequence of PDSCH DMRS notify initial condition to UE, generates and used the scramble sequence for the PDSCH DMRS scrambling to transmission based on this initial condition.

In Fig. 6, eNB determines in step 600 how the CSI-RS configuration relevant to DAS is set.ENB is the CSI-RS configuration to UE notice determined UE in step 600 by high-level signaling in step 610.After the CSI-RS configuration of notice UE, eNB in step 620 operation dispatching to determine which UE down-chain resource will be assigned to.After determining that in step 620 which UE PDSCH will be sent to, in step 630, whether eNB is that support is carried out corresponding operating for the UE of the new initial condition of DMRS scrambling according to UE.If determine that in step 630 UE does not support the new initial condition for PDSCH DMRS scrambling, eNB sends by the PDSCH DMRS of scramble sequence scrambling based on leaving over initial condition in step 640.If UE does not support new initial condition, as in step 640, do not send disclosed CoMP scrambling index in the present invention yet.

But if determine that in step 630 UE supports new initial condition, eNB determines that in step 650 which initial condition will be used to be generated to the scramble sequence of UE.In step 650, the initial condition that be applied to UE can be to leave over one of initial condition and new initial condition as in table 7 or table 8.In step 660, in step 650, definite initial condition is notified to UE via PDCCH or as the E-PDCCH of the enhancing channel of PDCCH.ENB sends to UE by PDSCH with PDSCH DMRS together with PDCCH.

In Fig. 6, suppose by CSI-RS and configure and determine new initial condition., suppose one of using method 1-4.In the time of using method 5 and method 6, also can application class like process, thereby which initial condition eNB can use to UE notice.

Fig. 7 illustrates according to following process of the present invention: the initial condition and the UE that are identified for the new scramble sequence of PDSCH DMRS determine which initial condition has been applied to the PDSCH DMRS sending from eNB.

In the step 700 of Fig. 7, the CSI-RS configuration that notice is relevant to DAS from eNB to UE.By utilizing the CSI-RS configuration of notice in step 700, UE identification is used for the initial condition of the new scramble sequence of PDSCH DMRS, and in such cases, can use one of disclosed method 1-4 in the present invention.Also can be by utilizing one of method 1-6 to be notified to the initial condition of UE for the new scramble sequence of PDSCH DMRS.No matter the CSI-RS of step 700 configuration how, which initial condition eNB can directly will use to UE notice by high-level signaling.

Identify the initial condition for the new scramble sequence of PDSCH DMRS in the step 700 of Fig. 7 and 710 at UE after, in step 720, utilize PDCCH or receive DCI (520) as shown in Figure 5 as the E-PDCCH of the enhancing channel of PDCCH.The UE that has received DCI in step 720 utilizes CoMP scrambling index 500 to identify initial condition, based on this initial condition, has generated the scramble sequence using.If in step 730, CoMP scrambling index is ' 00 ', and UE determines that in step 740 eNB utilization in the time sending the PDSCH DMRS of down link is used the scramble sequence of leaving over initial condition generation carry out scrambling and in step 760, receive Traffic Channel PDSCH.

But, if in step 730, CoMP scrambling index is not ' 00 ', and UE determines that scrambling is to utilize the scramble sequence generating by new initial condition to carry out, and by utilizing the scramble sequence in step 750 to receive Traffic Channel PDSCH in step 760.In Fig. 7, suppose that one of method 1-4 is used to the configuration according to CSI-RS and determines new initial condition, and CoMP scrambling index have 2 information and define as in table 7.Similarly, this process can be applied to method 5, method 6 and table 8.

In Fig. 7, only utilize CoMP scrambling index to be identified for the initial condition of the scrambling of DMRS.In addition, as in table 8, also can be applied to and process identical in Fig. 7 the use of SCID and CoMP scrambling index.That is, as in table 8, in Fig. 7, apply together CoMP scrambling index and SCID, in the step 720 of Fig. 7, receive CoMP scrambling index and SCID and in step 730, utilize subsequently CoMP scrambling index and SCID to determine initial condition.

In the LTE-A system of support DAS, E-PDCCH can be supported for the effective transmission to control channel.Fig. 8 illustrates the relation between E-PDCCH and PDSCH.In Fig. 8, in the specific part of 800 indicated Radio Resources, transmit E-PDCCH.E-PDCCH in part 800 is used to the required DCI of PDSCH of the particular UE indicated to UE notice reception 810.E-PDCCH is the enhancing channel that is used as the PDCCH that leaves over the control channel in LTE/LTE-A system, and different greatly with PDCCH in the following areas: E-PDCCH and PDSCH are similar also can be operated based on DMRS, but PDCCH always operates based on CRS.

In the time using E-PDCCH based on DMRS, must define initial condition, wherein PDCCH DMRS uses scramble sequence based on this initial condition.Usually, PDSCH DMRS, to UE notice E-PDCCH or PDCCH, uses the initial condition on them, has generated the initial condition of scramble sequence.

But, about the control channel such as E-PDCCH, there is not other control channel of notifying separately this.In order to address this problem, about E-PDCCH, to arrange in the present invention and use for generating one of multiple initial conditions for the scramble sequence of PDSCH DMRS.,, about E-PDCCH DMRS, always use the scramble sequence generating based on corresponding initial condition.E-PDCCH DMRS uses one of initial condition of PDSCH DMRS.For example, if there are four initial conditions applicatory as in table 7, one of these states are set to the initial condition for E-PDCCH by eNB.

Together with the DMRS of the scramble sequence scrambling that E-PDCCH is generated with utilizing the special initial condition based on default, send.For this reason, UE for each subframe do not notify or nonrecognition initial condition (based on this initial condition, scramble sequence is generated and is used to the scrambling to E-PDCCH) situation under, the scramble sequence of the initial condition by utilizing E-PDCCH based on for notifying in initial setting up receives E-PDCCH.

The scrambling initial condition that is used for the DMRS (or E-PDCCH DMRS) of E-PDCCH is set to one of scrambling initial condition of PDSCH DMRS.For the scrambling initial condition of E-PDCCH DMRS is set, eNB can utilize RRC signaling to use which scrambling initial condition for PDSCH DMRS to UE notice.Can determine by the pre-authorization method between UE and eNB the scrambling initial condition of E-PDCCH DMRS.In order to do like this, can use the scrambling initial condition in the middle of the transfer point that is provided with CS-RS configuration with the transfer point of maximum receiving intensity.Because UE can periodically notify to eNB the receiving intensity of the reference signal measured into each transfer point, so in the time utilizing said method, UE can be in the situation that not notifying separately from eNB, determine following initial condition: based on this initial condition, E-PDCCH is generated by scrambling and scramble sequence.

Although attached not shown, can in UE and BS, provide can carry out the present invention in disclosed operation and the processor (or controller) of method 1 to 6 according to an embodiment of the invention.

According to the present invention, in the case of the independent notice from eNB not, UE can identify initial condition, and wherein based on this initial condition, scramble sequence is generated and is used to the scrambling to E-PDCCH.

In addition, UE and eNB can be used for determining that the method for new initial condition realizes the interference randomization effect between the DMRS sending in the transfer point with same cells ID by utilization.

In addition, can utilize the method for determining new initial condition to obtain scramble sequence.

Although specifically illustrated and described the present invention with reference to embodiments of the invention, one of ordinary skill in the art will appreciate that and can make various embodiment or change to the present invention, and can not depart from the spirit and scope of the present invention that claim limits.Therefore, scope of the present invention should be defined by claim and equivalent thereof, instead of is defined by described embodiment.

Claims

1. for determine a method for initial condition at distributing antenna system (DAS), the method comprises: be worth by high-level signaling reception; And determine initial condition based on this value, and wherein, the instruction of this value is configured to the value of the initial condition of scramble sequence, and it is according to transfer point and difference.

2. the method for claim 1, wherein at least one in quantity and the antenna pattern of the position of described initial condition based on antenna port, antenna port determined.

3. the method for claim 1, wherein described value has 9.

4. the method for claim 1, wherein at least one in initial condition is to leave over initial condition.

5. be the method for claim 1, wherein the value previously arranging by high-level signaling for the initial condition of the physical downlink control channel (E-PDCCH) that strengthens.

6. for determine a device for initial condition at distributing antenna system (DAS), this device comprises: receiver, for being worth by high-level signaling reception; And controller, for determining initial condition based on this value, wherein, this value comprises other value of the initial condition that is configured to scramble sequence, it is according to transfer point and difference.

7. device as claimed in claim 6, wherein, at least one in quantity and the antenna pattern of the position of described initial condition based on antenna port, antenna port determined.

8. device as claimed in claim 6, wherein, described value has 9.

9. device as claimed in claim 6, wherein, at least one in initial condition is to leave over initial condition.

10. device as claimed in claim 6 wherein, is the value previously arranging by high-level signaling for the initial condition of the physical downlink control channel (E-PDCCH) that strengthens.

11. 1 kinds for determining the method for initial condition at distributing antenna system (DAS), and the method comprises: receive scrambled code mark (SCID); And SCID based on received, determine that determined initial condition leaves over initial condition or new initial condition.

12. methods as claimed in claim 11, also comprise: based on coordinated multipoint transmission (CoMP) scrambling index, determine that determined initial condition leaves over initial condition or new initial condition.

13. 1 kinds for determining the device of initial condition at distributing antenna system (DAS), and this device comprises: receiver, for receiving scrambled code mark (SCID); And controller, for the SCID based on received, determine that determined initial condition leaves over initial condition or new initial condition.

14. devices as claimed in claim 13, wherein, described controller is identified determined initial condition based on coordinated multipoint transmission (CoMP) scrambling index and is left over initial condition or new initial condition.