Background technology
Carrier aggregation system is a kind of system that a plurality of carrier resource polymerizations (or claiming to connect) are got up to use.As just at developing enhancing Long Term Evolution (Long Term Evolution Advanced, LTE-A) system, it is in order to support the system bandwidth wider than LTE system, for example in order to support the bandwidth of 100MHz, the resource of a plurality of LTE carrier waves (or claiming member carrier) is coupled together use.Can bind these carrier waves as the whole bandwidth of system, distribute to a user or give a plurality of users, as shown in Figure 1.Like this, when using for a user, can provide higher peak rate.Concrete, can be that a plurality of continuous LTE carrier waves are carried out polymerization, can be also a plurality of discontinuous LTE carrier waves are carried out polymerization.
In carrier aggregation system, need to pass through Physical Downlink Control Channel (Physical Downlink Control CHannel on descending carrier, PDCCH) send the signaling indication, with Physical Uplink Shared Channel (the Physical Uplink Sharing CHannel to up-link carrier, PUSCH) resource on and transmission block attribute are indicated, afterwards, descendingly feed back the reception correctness by mixed automatic retransfer request (Hybrid Automatic Repeat reQuest, HARQ).
The basic principle of HARQ is: the re-transmission of packet is carried out between transmitting terminal and receiving terminal, and in transmitting terminal and receiving terminal, one is the base station, and another is terminal.Feedback message comprises correctly replys (ACK) and wrong responses (NACK).The packet that the receiving terminal receiving end/sending end is sent, if correct the reception, feedback is correctly replied (ACK) message to transmitting terminal, show that current data packet correctly sends reception, and then transmitting terminal carries out the transmission of next packet; If receiving terminal is correct the reception not, feedback error is replied (NACK) message to transmitting terminal, and transmitting terminal can retransmit receiving terminal according to this message does not have the correct packet that receives.
In the LTE-A system, the process of feeding back ACK/NACK can be as shown in Figure 2:
S210: Physical Resource Block (the Physical Resource Block that the base station can take by descending PDCCH channel indication uplink transmission data, PRB) information such as demodulation reference mark of information and uplink (Demodulation Reference Symbol, DMRS).
The PRB information that can take, in fact comprise the minimum PRB numbering that the data of follow-up uplink can take in all PRB, mean recipient's (here as terminal) in follow-up uplink transmission data process, transmit from the place of this PRB numbering beginning the data that need transmission.DMRS is similar to the Midamble code in the TD-SCDMA system, is used for the follow-up processing such as uplink channel estimation.The general corresponding basic DMRS code in base station, and the DMRS that terminal adopts generally is based on this basic DMRS code and obtains after cyclic shift.The DMRS information of the upper indication of PDCCH, i.e. the circular shift information of the DMRS code of indicating terminal subsequent transmission upstream data process employing.
PRB information and the DMRS information of indication, general by DCI Downlink Control Information (Downlink Control Information, DCI) form 0 is indicated, and namely the base station indicates the PRB information that uplink transmission data can take (to be designated as by the DCI form 0 in PDCCH
) and DMRS information (be designated as n
DMRS) etc.
S220: terminal adopts Physical Uplink Shared Channel (Physical Uplink Sharing Channel, PUSCH) PRB and DMRS the transmission of data as indicated.
After the information such as the PRB that terminal is indicated on descending PDCCH in receiving aforementioned S210 and DMRS, the resource that begins from the minimum PRB that indicates on PUSCH is come transmit ascending data, and adopts the DMRS of indication.The front is mentioned DMRS and is used for uplink channel estimation, namely after subsequent base stations receives the data that terminal transmits by PUSCH, utilizes DMRS to do channel estimating, and then the upstream data that could utilize the further demodulation of channel estimation results to send.
S230: after the base station receives the up data of sending, by PHICH channel feedback ACK/NACK to terminal.
The base station utilizes the feedback mechanism in HARQ after receiving the data of transmitting on PUSCH, if correct receive data, feeding back ACK information is if correct receive data feeds back nack message.The ACK/NACK information of feedback after processing by modulation, spread spectrum and scrambling etc., is mapped to the transmitted over resources of PHICH channel.
The ACK/NACK of feedback takies a part of resource on PHICH, and this part resource is by parameter pair
Indicate.Wherein
The numbering of the group that adopts in expression PHICH,
Numbering be from 0 to
The index that represents the orthogonal sequence that adopts in a group.In fact, the resource that is used for transmitting in PHICH is divided into different groups, so need to indicate the group that transferring ACK/NACK adopts; In a group, mutually orthogonal different sequences can be arranged, and can adopt one of them sequence to come transferring ACK/NACK, therefore, also need to indicate the orthogonal sequence index of employing.
With
Calculate by following formula:
Wherein:
Be the number of the group of the PHICH in current subframe, can configure by high-level signaling;
The concept of PHICH group refers to the set of the elementary cell (Resource Element, RE) of one group of resource, can transmit 8 PHICH channels in the set of this RE, and each PHICH interchannel is distinguished by orthogonal sequence.For regular circulation prefix (Normal CP(Cyclic Prefix)), 8 orthogonal sequences can be arranged, in a PHICH group, 8 PHICH channels are arranged so; For extended cyclic prefix (Extended CP), 4 orthogonal sequences can be arranged, in a PHICH group, 4 PHICH channels are arranged so.
For the FDD system,
Fix in all subframes, and pass through following formula:
The size of the spreading factor during expression PHICH modulation;
N wherein
g∈ 1/6,1/2,1,2} can be provided by high level,
Can calculate by the downlink bandwidth information in broadcasting and obtain;
The numbering of the PRB of the minimum in the resource indication in expression DCI form 0;
n
DMRSBe the cyclic shift indication of the DMRS in DCI form 0, its definition can be as shown in the table:
The cyclic shift of DMRS in DCI form 0 |
n
DMRS |
000 |
0 |
001 |
1 |
010 |
2 |
011 |
3 |
100 |
4 |
101 |
5 |
110 |
6 |
111 |
7 |
Cyclic shift indication and the n of DMRS in table 1.DCI form 0
DMRSMapping relations
As seen, by top formula (1), can calculate to be used to indicate and be used for the parameter pair of resource of transferring ACK/NACK on PHICH
At present in the discussion about the LTE-A system, only considered the situation of uplink member carrier and one-tenth one-one relationship identical with the downlink member carrier number.This situation can have 3 uplink member carrier and 3 downlink member carriers as shown in example in Fig. 3, and these 3 uplink member carrier become 3 pairs with 3 downlink member carriers, and the uplink and downlink member carrier of every centering is man-to-man relation.
In fact, the situation that also exists the number of uplink member carrier and downlink member carrier not wait.As shown in Figure 4, show the downlink member carrier number greater than the uplink member carrier number; As shown in Figure 5, show the downlink member carrier number less than the uplink member carrier number.
For the situation in Fig. 4, namely for the situation of downlink member carrier number greater than the uplink member carrier number, having the definition of the PHICH of each downlink member carrier one to one of up-downgoing member carrier can realize in accordance with existing definition fully.That is to say, according to existing mode, each uplink member carrier, have downlink member carrier to come transferring ACK/NACK indication.
But, for example shown in Figure 5, be that the downlink member carrier number is less than the uplink member carrier number, except the uplink and downlink member carrier that has one-to-one relationship, also exist not corresponding with downlink member carrier uplink member carrier (as the uplink member carrier 3 in Fig. 5, can claim that this uplink member carrier is asymmetric uplink member carrier), in existing mode, also not about the scheme to asymmetric uplink member carrier feeding back ACK/NACK.
Embodiment
The embodiment of the present invention provides ACK/NACK transmission method and the base station in a kind of carrier aggregation system.
In order to make those skilled in the art person understand better the present invention program, below in conjunction with drawings and embodiments, the embodiment of the present invention is described in further detail.
Although only show the situation of a uplink member carrier in Fig. 5, but, one skilled in the art will appreciate that the technical scheme in the application can be applicable to the situation of a plurality of asymmetrical uplink member carrier widely, such as also comprise the situation of uplink member carrier 4 grades on the basis of Fig. 5.
At first, in the application, the corresponding relation between can pre-defined up/down row member carrier.Concrete, can define binding relationship by cell configuration between up/down row member carrier, as the PHICH of the ACK/NACK feedback of specifying asymmetrical uplink member carrier by which downlink member carrier carries.Up/down row member carrier for symmetry can keep its original symmetric relation, namely can keep the ACK/NACK feedback of uplink member carrier to transmit by the PHICH on its symmetrical downlink member carrier.
In Fig. 5, up/down row member carrier 1 and 2 has respectively relation one to one, can be carried by the PHICH on downlink member carrier 1 the ACK/NACK feedback of uplink member carrier 1, be carried the ACK/NACK feedback of uplink member carrier 2 by the PHICH on downlink member carrier 2.And for asymmetrical uplink member carrier 3, on the basis of Fig. 5, can also be as shown in Figure 6, pre-configured uplink member carrier 3 and downlink member carrier 1 or the downlink member carrier 2 of specifying by the residential quarter bound, in subsequent process, for asymmetrical uplink member carrier 3, can adopt the downlink member carrier 1 of binding or the PHICH on downlink member carrier 2 to come transferring ACK/NACK feedback.
For simplified characterization, below be illustrated to specify uplink member carrier 3 and downlink member carrier 2 to bind example, apparently, be equally applicable to specify the situation of uplink member carrier 3 and the binding of downlink member carrier 1.For downlink member carrier 3, it is except for uplink member carrier 2 feeding back ACKs that symmetric relation is arranged/NACK, also with uplink member carrier 3 as attached uplink member carrier, thereby to this uplink member carrier 3 feeding back ACKs/NACK.
Corresponding relation between above-mentioned said predefined up/down row member carrier, can notify to user terminal (User Equipment by high-level signaling or broadcast control message, UE), the i.e. downlink member carrier corresponding with described asymmetrical uplink member carrier, such corresponding relation can be notified to user terminal by high-level signaling or broadcast control message.
Signaling indication method embodiment in the application in a carrier aggregation system can as shown in Figure 7, comprise:
S710: receive the data of sending by the PUSCH on asymmetrical uplink member carrier.
S720: by the PHICH feeding back ACK/NACK on downlink member carrier.Wherein, described downlink member carrier is and the predefined corresponding downlink member carrier of described asymmetrical uplink member carrier.
In LTE-A, generally send data by the PUSCH on uplink member carrier, as previously mentioned, this PUSCH place carrier wave is asymmetrical uplink member carrier, thereby the base station receives the data of sending by the PUSCH on this asymmetric uplink member carrier.
In LTE-A, general by the PHICH feeding back ACK/NACK on downlink member carrier, this ACK/NACK is the feedback for the described up data of sending.The downlink member carrier at this PHICH place can be the corresponding downlink member carrier of asymmetric uplink member carrier at predefined described PUSCH place.
Especially, the downlink member carrier at described PHICH place can be the downlink member carrier at the PDCCH place of the described PUSCH of scheduling, and the system that is beneficial to like this will dispatch with indication information and be unified on identical downlink member carrier.
By above-described embodiment, can realize that the data of sending in the PUSCH to asymmetrical uplink member carrier carry out the ACK/NACK feedback.
As previously mentioned, the up data of sending by PUSCH in S710, the resource that the transmission of these data is shared can be determined by the information of notifying before.Determine the resource that can take in up PUSCH as the information such as demodulation reference mark of the PRB information that can take by descending PDCCH channel indication uplink transmission data before the base station and uplink.
PRB information comprises the minimum PRB numbering that the data transmitted in up PUSCH can take in all PRB, the up PUSCH the transmission of data of terminal needs the data of transmission from the place transmission of this PRB numbering beginning.DMRS is used for the follow-up processing such as uplink channel estimation.The general corresponding basic DMRS code in base station, and the DMRS that terminal adopts generally is based on this basic DMRS code and obtains after cyclic shift.The DMRS information of the upper indication of PDCCH, i.e. the circular shift information of the DMRS code of indicating terminal subsequent transmission upstream data process employing.
PRB information and the DMRS information of indication are generally indicated by DCI form 0, and namely the base station indicates the PRB information that uplink transmission data can take (to be designated as by the DCI form 0 in PDCCH
) and DMRS information (be designated as n
DMRS) etc.
The PHICH of the ACK/NACK information of feeding back by downlink bearing in S720, for the PUSCH transmission of dispatching in subframe n, UE determines at subframe n+k
PHICHIn the PHICH resource of correspondence, the FDD k of system wherein
PHICH=4, for TDD system, k
PHICHCan determine by following form:
Table 2.k
PHICHAllocation list
By the ACK/NACK of descending PHICH feedback, take a part of resource on PHICH in S720.The resource that this takies, the resource of PHICH channel are that the cyclic shift of the uplink demodulation reference symbol (DMRS) of PRB sequence number minimum in the resource of distributing of the row according to the PUSCH transmission permission indicating in the DCI form 0 of PDCCH and 3bits indication determines jointly.
Resource on the shared PHICH of ACK/NACK by downstream feedback in S720, concrete, as previously mentioned, mainly by parameter pair
Indication.
Wherein
The numbering of the group that adopts in expression PHICH,
Numbering be from 0 to
The index that represents the orthogonal sequence that adopts in a group.
With
Calculate by following formula:
Wherein:
Be the number of the group of the PHICH in current subframe, can configure by high-level signaling;
The size of the spreading factor during expression PHICH modulation;
The numbering of the PRB of the minimum in the resource indication in expression DCI form 0;
n
DMRSBe the cyclic shift indication of the DMRS in DCI form 0, its definition can be as shown in aforementioned table 1.
In the present embodiment, for the data of sending on asymmetrical uplink member carrier, the resource of the PHICH on the downlink member carrier of employing, in the calculating of above-mentioned formula (1), its
Can draw by following formula:
N wherein
g{ 1/6,1/2,1,2} can be provided by high level ∈;
Can calculate by the downlink bandwidth information in broadcasting and obtain.
In addition, in the present embodiment, N
gCan also be jointly to determine with the attribute of corresponding uplink member carrier according to the downlink member carrier at described PHICH place:
Wherein:
What represent is the number of the PRB that is used for up PUSCH transmission in i uplink member carrier;
Expression be described uplink member carrier the PRB number in predefined corresponding downlink member carrier K.I represents the numbering of uplink member carrier in the uplink member carrier of system at described PUSCH place; K represents the numbering of downlink member carrier in the downlink member carrier of system of described correspondence.
In addition, described N
g, can also be through the N after quantizing
g, also be used for the calculating of PHICH group.Here said quantification, be consider if with LTE in the definition of Ng compatible, can be so that the N after being calculated by formula (2)
gWith the N in LTE
gValue relatively, fall into which interval, just adopt which N
gBe configured.
In addition, in the embodiment of the present invention, for asymmetrical uplink member carrier, its PRB with corresponding other uplink member carrier of downlink member carrier of binding can also be coupled together and be numbered, afterwards, adopt described parameter the upper resource of the PHICH of indication to be transmitted the ACK/NACK of feedback, wherein the resource of parameter to indication, be minimum PRB numbering indicated after the PRB numbering couples together.
For example, in Fig. 6, the PRB number of uplink member carrier 2 is A, its PRB is numbered 0~A-1, the PRB number of uplink member carrier 3 is M, with the A~A+M-1 that is numbered of its PRB, obtain on the downlink member carrier 2 of the shared resource of ACK/NACK feedback to(for) forward data on uplink member carrier 3 by the right account form of described indication, account form is with described formula:
Wherein
Can be because the numbering of PRB couple together and change, in Fig. 6, after to be downlink member carrier 2 couple together with the PRB of downlink member carrier 3 of its indication, the minimum PRB numbering that represents on the PRB of this connection.
Below introduce the embodiment of the present invention one base station, Fig. 8 shows the block diagram of this base station embodiment, in Fig. 8, comprising:
Receiving element 81 is used for receiving the data of sending by the PUSCH on asymmetrical uplink member carrier;
Feedback unit 82 is used for by the PHICH feeding back ACK/NACK on downlink member carrier; Wherein, described downlink member carrier is and the predefined corresponding downlink member carrier of described asymmetrical uplink member carrier.
Preferably, the resource on the shared described PHICH of the ACK/NACK of described feedback is by parameter pair
Indication, wherein
The numbering of the group that adopts in expression PHICH,
Numbering be from 0 to
The index that represents the orthogonal sequence that adopts in a group;
With
Calculate by following formula:
Wherein:
Be the number of the group of the PHICH in current subframe, configure by high-level signaling;
The size of the spreading factor during expression PHICH modulation;
The numbering of the PRB of the minimum in the resource indication in expression DCI form 0;
n
DMRSIt is the cyclic shift indication of the DMRS in DCI form 0.
Preferably,
By determining by following formula:
N wherein
g{ 1/6,1/2,1,2} is provided by high level ∈;
Calculate by the downlink bandwidth information in broadcasting and obtain.
Preferably,
By determining by following formula:
Wherein:
Calculate by the downlink bandwidth information in broadcasting and obtain;
N
gJointly determine with the attribute of corresponding uplink member carrier according to the downlink member carrier at described PHICH place:
Wherein:
The number that represents the PRB that is used for up PUSCH transmission in i uplink member carrier;
Represent described uplink member carrier the PRB number in predefined corresponding downlink member carrier K; I represents the numbering of uplink member carrier in the uplink member carrier of system at described PUSCH place; K represents the numbering of downlink member carrier in the downlink member carrier of system of described correspondence.
Preferably, described
After the PRB that the minimum PRB of indication is numbered corresponding other uplink member carrier of downlink member carrier of asymmetrical uplink member carrier and binding couples together, the PRB of indicated minimum numbers.
Utilize above-mentioned base station embodiment to realize the method for ACK/NACK feedback, embodiment is similar with preceding method, does not repeat them here.
By above embodiment as seen, receive the data of sending by the PUSCH on asymmetrical uplink member carrier; By the PHICH feeding back ACK/NACK on downlink member carrier; Wherein, described downlink member carrier is and the predefined corresponding downlink member carrier of described asymmetrical uplink member carrier, thereby provide the data of sending for asymmetrical uplink member carrier to carry out the mode of ACK/NACK feedback, made up the deficiencies in the prior art.
Although described the embodiment of the present invention by embodiment, those of ordinary skills know, the present invention has many distortion and variation and do not break away from spirit of the present invention, wish that appended claim comprises these distortion and variation and do not break away from spirit of the present invention.