WO2014069912A1

WO2014069912A1 - Method and ue for transmitting harq-ack feedback information

Info

Publication number: WO2014069912A1
Application number: PCT/KR2013/009781
Authority: WO
Inventors: Jingxing Fu; Yingyang Li; Chengjun Sun
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2012-11-02
Filing date: 2013-10-31
Publication date: 2014-05-08
Anticipated expiration: 2015-05-02
Also published as: CN103795508A

Abstract

The present disclosure provides a method and a User Equipment (UE) for transmitting Hybrid-automatic Repeat-Request Acknowledgement (HARQ-ACK) feedback information in an Inter-eNB Carrier Aggregation (Inter-eNB CA) system. One method includes: obtaining, by a UE, HARQ-ACK timing of Component Carriers (CCs) configured in each eNB from a Pcell eNB; obtaining, by the UE, a transmission mode of the CCs configured in each eNB from the Pcell eNB, or obtaining, by the UE, the transmission mode of the CCs configured in the each eNB from the Pcell eNB and a Scell eNB; obtaining, by the UE, resources for transmitting the HARQ-ACK feedback information; transmitting, by the UE, the HARQ-ACK feedback information of Physical Downlink Shared Channel (PDSCH) data corresponding to the each eNB with the obtained resources for transmitting the HARQ-ACK feedback information according to the transmission mode of the CCs and the HARQ-ACK timing configured in the each eNB. The present disclosure may transmit the HARQ-ACK feedback information in the Inter-eNB CA system.

Description

METHOD AND UE FOR TRANSMITTING HARQ-ACK FEEDBACK INFORMATION

The present disclosure relates a wireless communication field, and more particularly, to a method and a User Equipment (UE) for transmitting Hybrid-automatic Repeat-Request Acknowledgement (HARQ-ACK) feedback information in an Inter-eNB Carrier Aggregation (Inter-eNB CA) system.

In the present Long Term Evolution (LTE) system, maximum bandwidth supported by each cell is 20MHz. In order to enhance peak rate of the UE, CA technologies are introduced in to the LTE-Advanced system. With the CA technologies, the UE may communicate with cells working at different carrier frequencies and controlled by the same eNB at the same time to make the transmission bandwidth up to 100MHz. UL (Uplink) and DL (Downlink) peak rates of the UE may be multiplied in theory.

As for the UEs working at the CA, the aggregated cells are divided into a Primary Cell (Pcell) and Secondary Cells (Scells).

In order to enlarge an application scope of the CA technology and further enhance the peak rate of the UE, the Inter-eNB CA technology may be the direction of development of the LTE-Advanced. The Inter-eNB CA technology refers to that cells performing data transmission with the same UE at the same time are no longer limited to the same eNB, i.e. these cells may belong to different eNBs. As shown in figure 1, the eNB including the Pcell is called a Pcell eNB. The eNB only including the Scells is called a Scell eNB. Therefore, in a network circumstance covered by different eNBs, working bandwidth of the UE may be increased via the CA technology.

Features of the Inter-eNB CA technology are different those of a conventional Intra-eNB CA technology, which causes now problems to application of the CA technology. For instance, in the process of transmitting the HARQ-ACK feedback information, at present the HARQ-ACK feedback information only can be transmitted on the PCell. In addition, resources used for transmitting the HARQ-ACK feedback information are mapped from the lowest Control Channel Element (CCE) index used by the PDCCH for scheduling the Physical Downlink Shared Channel (PDSCH) or indicated by a HARQ-ACK Resource Indicator (ARI) domain in the PDCCH scheduling the PDSCH. In the Inter-eNB system, transmitted PDSCH data of Component Carriers (CCs) in different eNBs is scheduled by different eNBs. Furthermore, the used lowest CCE index used by the PDCCH for scheduling of different eNBs and resources indicated by the ARI domain in the PDCCH scheduling the PDSCH cannot be shared by different eNBs. That is, one eNB does not know the lowest CCE index information of the PDCCH used by another eNB for scheduling and the resources indicated by the ARI domain in the PDCCH scheduling the PDSCH. Therefore, the current HARQ-ACK feedback information transmission technology cannot be used normally.

It can be seen that in the Inter-eNB CA technology, many new problems in the transmission of the HARQ-ACK feedback information need to be solved. The method described in the conventional LTE-Advanced protocol cannot be simply copied. As for the result of the current research, there is no solution for these problems.

In view of the above, the present disclosure provides two methods and UEs for transmitting the HARQ-ACK feedback information in the Inter-eNB CA system, by which the HARQ-ACK feedback information may be transmitted in the Inter-eNB CA system.

In order to achieve the above objective, the technical scheme of the present disclosure is implemented as follows:

A method for transmitting Hybrid-automatic Repeat-Request Acknowledgement (HARQ-ACK) feedback information in an Inter-eNB Carrier Aggregation (Inter-eNB CA) system includes:

obtaining, by a User Equipment (UE), HARQ-ACK timing of Component Carriers (CCs) configured in each eNB from a Pcell eNB;

obtaining, by the UE, a transmission mode of the CCs configured in each eNB from the Pcell eNB, or obtaining, by the UE, the transmission mode of the CCs configured in the each eNB from the Pcell eNB and a Scell eNB;

obtaining, by the UE, resources for transmitting the HARQ-ACK feedback information;

transmitting, by the UE, the HARQ-ACK feedback information of Physical Downlink Shared Channel (PDSCH) data corresponding to the each eNB with the obtained resources for transmitting the HARQ-ACK feedback information according to the transmission mode of the CCs and the HARQ-ACK timing configured in the each eNB.

A User Equipment (UE) for transmitting Hybrid-automatic Repeat-Request Acknowledgement (HARQ-ACK) feedback information in an Inter-eNB Carrier Aggregation (Inter-eNB CA) system includes

an information obtaining module, to obtain HARQ-ACK timing of Component Carriers (CC)s configured in each eNB from a Pcell eNB, obtain a transmission mode of the CCs configured in the each eNB from the Pcell eNB, or obtain the transmission mode of the CCs configured in the each eNB from the Pcell eNB and a Scell eNB;

a resource obtaining module, to obtain resources for transmitting the HARQ-ACK feedback information; and

a transmission module, to transmit the HARQ-ACK feedback information of Physical Downlink Shared Channel (PDSCH) data corresponding to the each eNB with the obtained resources for transmitting the HARQ-ACK feedback information according to the transmission mode of the CCs and the HARQ-ACK timing configured in the each eNB.

A method for transmitting HARQ-ACK feedback information in an Inter-eNB Carrier Aggregation (Inter-eNB CA) system includes

obtaining, by a User Equipment (UE), resources for transmitting the HARQ-ACK feedback information of different eNBs respectively and transmitting the HARQ-ACK feedback information of the different eNBs respectively on the resources.

A User Equipment (UE) for transmitting HARQ-ACK feedback information in an Inter-eNB CA system includes

a resource obtaining module, to obtain resources for transmitting the HARQ-ACK feedback information of different eNBs respectively; and

a transmission module, to transmit the HARQ-ACK feedback information of the different eNBs respectively on the resources.

In view of the above, with the method and UE for transmitting the HARQ-ACK feedback information in the Inter-eNB CA system provided by the present disclosure, uniform transmission of the HARQ-ACK feedback information or the separate transmission of the HARQ-ACK feedback information may be implemented in the Inter-eNB CA system via performing relevant configurations at the eNB and UE side.

Additional aspects and advantages of the present disclosure are made more apparent via the following description or known from practices of the present disclosure.

Figure 1 is a schematic diagram illustrating Inter-eNB CA in the prior art;

Figure 2 is a flow chart illustrating a first method for transmitting HARQ-ACK feedback information in an Inter-eNB CA system in accordance with an embodiment of the present disclosure;

Figure 3 is a schematic diagram illustrating arrangement of HARQ-ACK bits in a first embodiment;

Figure 4 is a schematic diagram illustrating arrangement of HARQ-ACK bits in a second embodiment;

Figure 5 is a schematic diagram illustrating arrangement of HARQ-ACK bits in a third embodiment;

Figure 6 is a flow chart illustrating a second method for transmitting HARQ-ACK feedback information in an Inter-eNB CA system in accordance with an embodiment of the present disclosure;

Figure 7 is a schematic diagram illustrating arrangement of HARQ-ACK bits in the second method;

Figure 8 is a schematic diagram illustrating a first structure of a UE in accordance with an embodiment of the present disclosure; and

Figure 9 is a schematic diagram illustrating a second structure of a UE in accordance with an embodiment of the present disclosure.

Embodiments of the present disclosure are described hereinafter in detail. Examples of the embodiments are shown in the accompanying figures. Throughout the disclosure, a same or similar label denotes the same or similar element or an element with the same or similar function. The embodiments described hereinafter with reference to accompanying figures are illustrative, are used for explaining the present disclosure but should not be interpreted as limitations to the present disclosure.

The present disclosure mainly refers to a system adopting Inter-eNB CA, as for a PCell eNB and a SCell eNB of the CA, if the two eNBs are connected with an X2 interface, a logic connection of the X2 interface is established between the PCell eNB and the SCell eNB and then signaling interaction between the PCell eNB and the SCell eNB is performed via the established logic connection. If there is no X2 interface connection, a logic connection of an S1 interface is established between the PCell eNB and the MME. An S1 logic connection is established between the SCell eNB and the MME. Then, the signaling interaction between the PCell eNB and the SCell eNB is performed via the two S1 logic connections and is forwarded by the MME.

In order to implement the objective of the present disclosure, the present disclosure provides two methods for transmitting the HARQ-ACK feedback information in the Inter-eNB CA system. Figure 2 is a flow chart illustrating a method for transmitting HARQ-ACK feedback information in an Inter-eNB CA system in accordance with an embodiment of the present disclosure. The method includes the following blocks.

In block 201, a UE obtains HARQ-ACK timing of CCs configured in each eNB from a Pcell eNB.

The UE obtains a transmission mode of the CCs configured in each eNB from the Pcell eNB. Alternatively, the UE obtains the transmission mode of the CCs configured in each eNB from the Pcell eNB and a Scell eNB.

In block 202, the UE obtains resources for transmitting HARQ-ACK feedback information.

In block 203, the UE transmits the HARQ-ACK feedback information of the PDSCH data corresponding to each eNB with the obtained resources for transmitting the HARQ-ACK feedback information according to the obtained transmission mode of the CCs and the HARQ-ACK timing configured in each eNB in block 201.

eNBs need to perform information interaction and are used for configuring a mode for a terminal device to transmit the HARQ-ACK feedback information and a mode for the eNBs to receive the HARQ-ACK feedback information from the terminal device. The interacted information between the eNBs includes the number of CCs configured by each eNB, a transmission mode (a Single Input Multiple Out (SIMO) transmission mode or a Multiple Input Multiple Output (MIMO) transmission mode) of each CC and HARQ-ACK timing of each CC (i.e. a Frequency Division Duplexing (FDD) configuration or a TDD UL and DL configuration in a Time Division Duplexing (TDD) mode). The information interaction may be performed between the eNBs via the X2 interface or the S1 interface.

A method for performing information interaction between the eNBs includes that the PCell eNB sends information to the Scell eNB. The information includes the number of CCs configured by the Pcell eNB, the number of CCs configured by the Scell eNB, the transmission mode of the CCs configured by the Pcell eNB, the transmission mode of the CCs configured by the Scell eNB and the HARQ-ACK timing of the CCs configured by the Pcell eNB. The Scell eNB sends information to the Pcell eNB. The information includes the HARQ-ACK timing of the CCs configured by the Scell eNB.

Another method for performing the information interactive between the eNBs includes that the Pcell eNB sends the information to the Scell eNB. The information includes the number of the CCs configured by the Pcell eNB, the number of the CCs configured by the Scell eNB, the transmission mode of the CCs configured by the Pcell eNB and the HARQ-ACK timing of the CCs configured by the Pcell eNB. The Scell eNB sends the information to the Pcell eNB. The information includes the HARQ-ACK timing of the CCs configured by the Scell eNB and the transmission mode of the CCs configured by the Scell eNB.

In the above block 201, the UE obtains the number of the CCs configured by the Pcell eNB and the number of CCs configured by the Scell eNB via Radio Resource Control (RRC) signaling configured by the Pcell eNB. The UE obtains the HARQ-ACK timing of the Pcell via synchronization channel and system information (SIB 1). The UE obtains the HARQ-ACK timing of the Scell via the RRC singling configured by the Scell eNB.

In the above block 201, a mode for the UE to obtain the transmission mode of the CCs configured by each eNB from the Pcell eNB includes that the UE obtains the transmission mode of the CCs configured by each eNB via the Radio Resource Control (RRC) signaling sent from the Pcell eNB. That is, the UE obtains the transmission mode of the CCs configured by the Pcell eNB and the transmission mode of the CCs configured by the Scell eNB from the RRC singling sent from the Pcell eNB.

A mode for the UE to obtain the transmission mode of the CCs configured in each eNB from the PCell eNB and the Scell eNB includes that the UE respectively obtains the transmission mode of the CCs configured in the eNB from the RRC singling sent from the Pcell eNB and the Scell eNB.

In the above block 202, a mode for obtaining the resources for transmitting the HARQ-ACK feedback information includes that the UE obtains the resources for transmitting the HARQ-ACK feedback information via reading the RRC singling. The mode at least includes the following two scenarios.

In scenario one, when the transmission of the HARQ-ACK feedback information adopts Physical Uplink Control Channel (PUCCH) format 3, the UE obtains the resources of the PUCCH format 3 via reading the RRC singling. The resources read by the UE are the resources of fixed PUCCH format 3, but are not the resources of dynamically-changed PUCCH format 3.

In scenario two, when the transmission of the HARQ-ACK feedback information adopts PUCCH format 1b with channel selection, the UE obtains the resources of the PUCCH format 1b via reading the RRC singling. The resources read by the UE are the resources of fixed PUCCH format 1b, but are not the resources of dynamically-changed PUCCH format 1b. A mode for allocating the resources includes that the UE obtains two resources of the PUCCH format 1b for each CC.

As for the second situation described in block 202, block 203 includes different methods for transmitting the HARQ-ACK feedback information.

As for the scenario one:

A method for transmitting the HARQ-ACK feedback information includes that the UE arranges HARQ-ACK feedback information bits of the Physical Downlink Shared Channel (PDSCH) data sent from different eNBs on the obtained resources of the PUCCH format 3 in a specific order. The specific arrangement method is described hereinafter in detail.

A method for arranging the HARQ-ACK feedback information bits of the PDSCH data sent from different eNBs includes arranging the HARQ-ACK feedback information bits of the PDSCH data of each CC from the front to the end in turn according to the transmission mode and the HARQ-ACK timing of all the CCs in each eNB and the indexes of the Component Carriers (CC)s configured in each eNB.

In the above block, suppose that there are two eNBs, denoted as eNB0 and eNB1. Each eNB includes a CC. The CC in eNB0 is CC0 and the CC in the eNB1 is CC1. The configuration of the CC0 is the FDD. A configured bundling window M is M0 with the value of 1, while the CC1 is the TDD. The bundling window M of TDD UL and DL configuration of the CC1 is M1. The HARQ-ACK feedback information of jth sub-frame in the bundling window in ith CC may be denoted as HARQ-ACK (i, j), i equals to 0 or 1. As for the first CC, j equals to 0,…, M0-1. As for the second CC, j equals to 0, …, M1-1.

If the eNB0 sends only one codeword on a sub-frame of the CC0 in the SIMO mode, the obtained HARQ-ACK feedback information, i.e. HARQ-ACK (i, j) of the sub-frame on the CC0 is one HARQ-ACK information bit, denoted as b (0, 0).

If the eNB1 sends two code words on a sub-frame of the CC1 in the MIMO mode, the HARQ-ACK feedback information, i.e. HARQ-ACK (i, j) of the sub-frame on the CC1 is two HARQ-ACK information bits, denoted as b_0(1, j) and b_1(1, j). b_0(1, j) is the HARQ-ACK information bit generated by the first codeword and b_1(1, j) is the HARQ-ACK information bit generated by the second code word. The arrangement of the HARQ-ACK feedback information of the eNB1 is { b_0(1, 0)，b_1(1, 0)，b_0(1, 1)，b_1(1, 1)，…b_0(1, M1-1)，b_1(1, M1-1)}.

The arrangement of the HARQ-ACK feedback information of the UE is {b(0, 0)，b_0(1, 0)，b_1(1, 0)，b_0(1, 1)， b_1(1, 1)，…b_0(1, M1-1)，b_1(1, M1-1)}.

Embodiment one: Suppose that two eNBs, i.e. the Pcell eNB and the Scell eNB, are configured for the UE. The Pcell eNB is configured with the Pcell and the Scell eNB is configured with the Scell. The UE is configured to transmit the HARQ-ACK feedback information using PUCCH format 3. The Pcell is FDD and adopts the MIMO transmission mode. The HARQ-ACK feedback information, i.e. HARQ-ACK (i, j) obtained by the Pcell has two HARQ-ACK information bits, denoted as b_0(0, 0) and b_1(0, 0). The Scell adopts TDD UL and DL configuration 2 and the SIMO transmission mode. The HARQ-ACK feedback information, i.e. HARQ-ACK(i, j) obtained by the Scell has four HARQ-ACK information bits, respectively denoted as {b_0(1, 0), b_0(1, 1), b_0(1, 2) and b_0(1, 3)}.

As shown in figure 3, the arrangement of the HARQ-ACK feedback information of the UE is {b_0(0, 0), b_1(0, 0), b_0(1, 0), b_0(1, 1), b_0(1, 2) and b_0(1, 3)}.

Another method for arranging the HARQ-ACK feedback information bits of the PDSCH data of the CCs configured in different eNBs is that each eNB respectively arranges the HARQ-ACK feedback information bits according to different starting points and directions.

A method for arranging the HARQ-ACK feedback information bits of the PDSCH data of the CCs configured in different eNBs is that when the CCs of the CA respectively belong to two eNBs, according to the transmission mode and HARQ-ACK timing of all the CCs in each eNB, the HARQ-ACK feedback information bits of the PDSCH data of the CCs configured in a eNB are arranged from the front to the end according to the indexes of the CCs and the HARQ-ACK feedback information bits of the PDSCH data of the CCs configured in another eNB are arranged from the end to the front according to the indexes of the CCs.

In the above block, suppose that there are two eNBs, denoted as eNB0 and eNB1. Each eNB includes a CC. The CC in the eNB0 is CC0 and the CC in the eNB1 is CC1. The CC0 is the FDD configuration. A configured bundling window M is M0 with the value of 1, while the configuration of the CC1 is the TDD. The bundling window M of TDD UL and DL configuration of the CC1 is M1. The HARQ-ACK feedback information of jth sub-frame in the bundling window of ith CC may be denoted as HARQ-ACK (i, j), i equals to 0 or 1. As for the first CC, j equals to 0,…, M0-1. As for the second CC, j equals to 0, …, M1-1.

If the eNB0 sends only one codeword on a sub-frame of the CC0 in the SIMO mode, the obtained HARQ-ACK feedback information, i.e. HARQ-ACK (i, j) of the sub-frame on the CC0 is one HARQ-ACK information bit, denoted as b(0，0).

If the eNB1 sends two code words on a sub-frame of the CC1 in the MIMO mode, the HARQ-ACK feedback information, i.e. HARQ-ACK (i, j) of the sub-frame on the CC1 has two HARQ-ACK information bits, denoted as b_0(1, j) and b_1(1, j). b_0(1, j) is the HARQ-ACK information bit generated by the first codeword and b_1(1, j) is the HARQ-ACK information bit generated by the second code word. The arrangement of the HARQ-ACK feedback information of the eNB1 is { b_0(1, 0)，b_1(1, 0)，b_0(1, 1)，b_1(1, 1)，…b_0(1, M1-1)，b_1(1, M1-1)}.

According to a principle that the HARQ-ACK feedback information bits of the PDSCH data of all the CCs of a eNB are arranged from the front to the end according to the indexes and the HARQ-ACK feedback information bits of the PDSCH data of all the CCs of another eNB are arranged from the end to the front according to the indexes, the arrangement of the HARQ-ACK feedback information of the UE is {b(0, 0),…… b_0(1, M1-1), b_1(1, M1-1),…,b_0(1, 1), b_1(1, 1), b_0(1, 0), b_1(1, 0)}. There may be some vacant bits between the HARQ-ACK feedback information bits of the eNB0 and the HARQ-ACK feedback information bits of the eNB1.

Embodiment two: Suppose that two eNBs, i.e. the Pcell eNB and the Scell eNB, are configured for the UE. The Pcell eNB is configured with the Pcell and the Scell eNB is configured with the Scell. The UE is configured to transmit the HARQ-ACK feedback information with PUCCH format 3. The Pcell is FDD and adopts the MIMO transmission mode. The HARQ-ACK feedback information, i.e. HARQ-ACK (i, j) obtained by the Pcell has two HARQ-ACK information bits, denoted as b_0(0, 0) and b_1(0, 0). b_0(0, 0) is the HARQ-ACK information bit generated by the first codeword and b_1(0, 0) is the HARQ-ACK information bit generated by the second codeword. The Scell adopts TDD UL and DL configuration 2 and the SIMO transmission mode. The HARQ-ACK feedback information, i.e. HARQ-ACK(i, j) obtained by the Scell has four HARQ-ACK information bits, respectively denoted as b_0(1, 0), b_0(1, 1), b_0(1, 2) and b_0(1, 3). b_0(1, 0) is the HARQ-ACK information bit generated by the zero-th DL sub-frame in the bundling window. b_0(1, 1) is the HARQ-ACK information bit generated by the first DL sub-frame in the bundling window. b_0(1, 2) is the HARQ-ACK information bit generated by the second DL sub-frame in the bundling window. b_0(1, 3) is the HARQ-ACK information bit generated by the third DL sub-frame in the bundling window.

As shown in figure 4, the arrangement of the HARQ-ACK feedback information of the UE is {b_0(0, 0), b_1(0, 0),…. b_0(1, 3), b_0(1, 2), b_0(1, 1) and b_0(1, 0)}.

Another method for arranging the HARQ-ACK feedback information bits of the PDSCH data of different eNBs is that the HARQ-ACK feedback information bits of the PDSCH data of the CCs configured in different eNBs are arranged from the front to the end according to specific starting points and the indexes of the CCs configured in the eNBs.

In the above blocks, suppose that there are three eNBs, denoted as eNB0, eNB1 and eNB2. Each eNB includes a CC. The CC in eNB0 is CC0, the CC in the eNB1 is CC1 and the CC in the eNB2 is CC2. The CC0 is the FDD. A configured bundling window M is M0 with the value of 1, while the CC1 is the TDD. The bundling window M of TDD UL and DL configuration of the CC1 is M1. The CC2 is the TDD. The bundling window M of TDD UL and DL configuration of the CC2 is M2. The HARQ-ACK feedback information of jth sub-frame in the bundling window of ith CC may be denoted as HARQ-ACK (i,j), i equals to 0, 1 or 2. As for the first CC, j equals to 0,…, M0-1. As for the second CC, j equals to 0, …, M1-1. As for the third CC, j equals to 0, …, M2-1.

If the eNB0 sends only one codeword on a sub-frame of the CC0 in the SIMO mode, the obtained HARQ-ACK feedback information, i.e. HARQ-ACK(i, j) of the sub-frame on the CC0 is one HARQ-ACK information bit, denoted as b(0，0).

If the eNB1 sends two code words on a sub-frame of the CC1 in the MIMO mode, the HARQ-ACK feedback information, i.e. HARQ-ACK (i, j) of the sub-frame on the CC1 has two HARQ-ACK information bits, denoted as b_0(1, j) and b_1(1, j). The arrangement of the HARQ-ACK feedback information of the eNB1 is { b_0(1, 0)，b_1(1, 0)，b_0(1, 1)，b_1(1, 1)，…b_0(1, M1-1)，b_1(1, M1-1)}.

If the eNB2 performs transmission on a sub-frame of the CC2 in the MIMO mode, the HARQ-ACK feedback information, i.e. HARQ-ACK (i, j) of the sub-frame on the CC2 is one HARQ-ACK information bit, denoted as b_0(2, j). The arrangement of the HARQ-ACK feedback information of the eNB1 is { b_0(2, 0)，b_0(2, 1)…b_0(2, M2-1)}.

Suppose that the starting point of the HARQ-ACK feedback information bits of the eNB0 is s0, the starting point of the HARQ-ACK feedback information bits of the eNB1 is s1 and the starting point of the HARQ-ACK feedback information bits of the eNB2 is s2. For instance, S0 equals to 0, s1 is rounded up (20/3) = 7 and s2 is rounded up(20 * 2/3) = 14.

The arrangement of the HARQ-ACK feedback information of the UE is

Embodiment 3: Suppose that the UE is configured with three eNBs, i.e. the Pcell eNB, the Scell 1 eNB and the Scell 2 eNB. The Pcell eNB is configured with the Pcell, the Scell 1 eNB is configured with the Scell 1 and the Scell 2 eNB is configured with the Scell 2. The UE is configured to transmit the HARQ-ACK feedback information with a PUCCH format 3 mode. The Pcell is the FDD and is in the MIMO transmission mode. The HARQ-ACK feedback information, i.e. HARQ-ACK (i, j) obtained by the Pcell has two HARQ-ACK information bits, denoted as b_0(0, 0) and b_1(0, 0). b_0(0, 0) is the HARQ-ACK information bit generated by the first codeword. b_1(0, 0) is the HARQ-ACK information bit generated by the second codeword. The Scell 1 is the TDD UL and DL configuration 2 and adopts the SIMO transmission mode. The HARQ-ACK feedback information, i.e. HARQ-ACK(i, j) on the Scell has four HARQ-ACK information bits, denoted as b_0(1, 0), b_0(1, 1), b_0(1, 2)，b_0(1, 3). b_0(1, 0) is the HARQ-ACK information bit generated by the zero-th DL sub-frame in the bundling window. b_0(1, 1) is the HARQ-ACK information bit generated by the first DL sub-frame in the bundling window. b_0(1, 2) is the HARQ-ACK information bit generated by the second DL sub-frame in the bundling window. b_0(1, 3) is the HARQ-ACK information bit generated by the third DL sub-frame in the bundling window. The Scell 2 is the TDD UL and DL configuration 1 and adopts the SIMO transmission mode. The HARQ-ACK feedback information, i.e. HARQ-ACK (i, j) on the Scell has two HARQ-ACK information bits, denoted as b_0(2, 0) and b_0(2, 1). b_0(2, 0) is the HARQ-ACK information bit generated by the zero-th DL sub-frame in the bundling window. b_0(2, 1) is the HARQ-ACK information bit generated by the first DL sub-frame in the bundling window.

As shown in figure 5, the arrangement of the HARQ-ACK feedback information of the UE is

As for scenario two:

In the block 203, the method for transmitting the HARQ-ACK feedback information includes that the UE transmits the HARQ-ACK feedback information bits of the PDSCH data from different eNBs with the obtained resources of the PUCCH format 1b in a PUCCH format 1b with the channel selection. The specific mapping mode is described hereinafter in detail.

The method for transmitting the HARQ-ACK feedback information bits of the PDSCH data from different eNBs with in a PUCCH format 1b with the channel selection includes: generating at most two-bit HARQ-ACK feedback information of the PDSCH data of the CC respectively according to the transmission mode and the HARQ-ACK timing of each CC and mapping the two-bit HARQ-ACK feedback information bit of the PPDSCH data of the CC with the PUCCH format 1b with the channel selection.

The method for generating at most two-bit HARQ-ACK feedback information is as follows.

If the size of the bundling window of the CC is one, when the CC is configured as SIMO transmission, its HARQ-ACK feedback information is one bit. If the CC is configured as the MIMO transmission, its HARQ-ACK feedback information has two bits. Alternatively, space bundling is performed on its HARQ-ACK feedback information to generate one-bit HARQ-ACK feedback information.

If the size of the bundling window of the CC is two, when the CC is configured as the SIMO transmission, its HARQ-ACK feedback information has two bits. If the CC is configured as the MIMO transmission, its HARQ-ACK feedback information has four bits. Alternatively, space bundling is performed on its four-bit HARQ-ACK feedback information to generate two-bit HARQ-ACK feedback information.

If the size of the bundling window of the CC is larger than two, when the CC is configured as the SIMO transmission, time domain bundling is performed on its HARQ-ACK feedback information to generate two-bit HARQ-ACK feedback information. If the CC is configured as the MIMO transmission, space bundling is performed on its HARQ-ACK feedback information first, and then time domain bundling is performed on the HARQ-ACK feedback information after the space bundling to generate the two-bit HARQ-ACK feedback information.

The size of the bundling window configured by the FDD is one, the size of the bundling window configured by the TDD is two or larger than two.

Two resources of the PUCCH format 1b used by each CC is allocated via the RRC singling.

Embodiment four:

In this embodiment, suppose that the CC0 is the primary cell, the size of the bundling window is three and the MIMO transmission is adopted. The CC1 is the secondary cell and the size of the bundling window is 1. Therefore, since the size of the bundling window of the CC0 is 3, if the MIMO transmission is adopted, the space bundling needs to be performed first. In this way, whether the MIMO transmission or the SIMO transmission is adopted, the CC0 may obtain the three-bit HARQ-ACK feedback information and the CC1 may obtain the one-bit HARQ-ACK feedback information. Therefore, referring to table 1, the three-bit HARQ-ACK feedback information of the CC0 is mapped into two bits first and a Discontinuous Transmission (DTX) is added to the end of the HARQ-ACK feedback information of the CC1. Then, the CC0 and CC1 perform the mapping adopting a table, in which the resource A equals to four in the PUCCH format 1b with the channel selection in the 3GPP 36.213. Resources of each CC are allocated via the RRC singling.

Table 1

Another method for transmitting the HARQ-ACK feedback information bits of the PDSCH data from different eNBs using the PUCCH format 1b with the channel selection includes that M-bit HARQ-ACK feedback information of the PDSCH data of the CC is respectively generated according to the transmission mode and the HARQ-ACK timing of each CC and the generated two HARQ-ACK feedback information bits of the PDSCH data of the CCs are mapped with the PUCCH format 1b with the channel selection. M is the maximum value of the bundling window of the two CCs and the size of the bundling window of each CC is determined according to its HARQ-ACK timing.

Specifically, the larger one of the sizes of the bundling windows of the two CCs is denoted as M which equals to max{Mp，Ms}. The HARQ-ACK feedback information is transmitted with the PUCCH format 1b with the channel selection using a mapping table, in which M equals to max{Mp，Ms} in 3GPP version 10. Mp is the size of the bundling window of the Pcell. Ms is the size of the bundling window of the Scell. As for the CC with the lowest bundling window, the UE adds （M-min{Mp，Ms}）DTX to the end of the HARQ-ACK feedback information of the CC and the size of the bundling window of the CC is min{Mp, Ms}.

Two resources of the PUCCH format 1b used by each CC are allocated via the RRC singling.

Embodiment five:

In this embodiment, suppose that the CC0 is the primary cell, the size of the bundling window is three and the MIMO transmission is adopted. The CC1 is the secondary cell and the size of the bundling window is one. The mapping is performed taking the larger one of the sizes of the bundling windows of the two CCs as the PUCCH format 1b with the channel selection. M=max{3,1}=3. Since the size of the bundling window of the CC0 is three, the size of the bundling window of the CC1 is one. 3-1=2 DTX is added to the end of the HARQ-ACK feedback information of the CC1. Then, the mapping is performed adopting the table, in which M=3 in the 3GPP 36.213 protocol. The resource

of each CC is allocated via the RRC singling.

The present disclosure provides another method for transmitting the HARQ-ACK feedback information in the Inter-eNB CA system. As shown in figure 6, the method includes the following blocks.

In block 601, the UE respectively obtains resources for transmitting the HARQ-ACK feedback information of different eNBs.

In block 602, the UE transmits the HARQ-ACK feedback information of different eNBs adopting the resources obtained in block 601 for transmitting the HARQ-ACK feedback information of different eNBs.

In the block 601, a method for obtaining the resources for transmitting the HARQ-ACK feedback information includes that the UE respectively obtains the PUCCH resources used for transmitting the HARQ-ACK feedback information of different eNBs via the lowest Control Channel Element (CCE) used by the PDCCH scheduling the PDSCH of the different eNBs or via an ARI domain indicator in the PDCCH scheduling the PDSCH of the different eNBs.

Before the above block 601, the UE may obtain a PUCCH transmission format of the HARQ-ACK feedback information configured by the Pcell eNB from the Pcell via the RRC singling and obtain a PUCCH transmission format of the HARQ-ACK feedback information configured by the Scell eNB from the secondary Pcell of the Scell eNB. The PUCCH transmission format includes PUCCH format 1b and PUCCH format 3. The PUCCH resources used by the Pcell eNB for transmitting the HARQ-ACK feedback information and the PUCCH resources used by different Scell eNBs for transmitting the HARQ-ACK feedback information are independent. The secondary Pcell refers to the Scell in the Scell eNB for transmitting the control singling.

Suppose that there are two eNBs, denoted as eNB0 and eNB1. Each eNB includes a CC. The CC in the eNB0 is the CC0 and the CC in the eNB1 is the CC1. Before block 601, the transmission mode of the HARQ-ACK feedback information configured in the eNB0 and obtained by the UE is the PUCCH format 1b. The transmission mode of the HARQ-ACK feedback information configured by the eNB1 is the PUCCH format 3. Therefore, in the block 601, as for the Pcell in the eNB0, the resources of the PUCCH format 1b are obtained by the lowest CCE index used by PDCCH for scheduling the PDSCH of the different eNBs. As for the Scell in the eNB0, if the Scell is scheduled by the Pcell Inter-carrier, the resources of the PUCCH format 1b of the Scell are obtained by the lowest CCE index used by the PDCCH for scheduling the PDSCH of the different eNBs. If the Scell is scheduled by itself, its resources of the PUCCH format 1b are obtained by the ARI indicator in the PDCCH scheduling the PDSCH of the eNB. As shown in figure 7, as for the Scell in the eNB1, its resources of the PUCCH format 3 are obtained by the ARI indicator in the PDCCH scheduling the PDSCH of the eNB.

The present disclosure further provides a UE for transmitting HARQ-ACK feedback information in an Inter-eNB CA system. Figure 8 is a schematic diagram illustrating structure of a first UE in accordance with an embodiment of the present disclosure. The UE includes:

an information obtaining module 801, to obtain HARQ-ACK timing of Component Carriers (CC)s configured in each eNB from a Pcell eNB, obtain a transmission mode of the CCs configured in the each eNB from the Pcell eNB, or obtain the transmission mode of the CCs configured in the each eNB from the Pcell eNB and a Scell eNB;

a resource obtaining module 802, to obtain resources for transmitting the HARQ-ACK feedback information; and

a transmission module 803, to transmit the HARQ-ACK feedback information of Physical Downlink Shared Channel (PDSCH) data corresponding to the each eNB with the obtained resources for transmitting the HARQ-ACK feedback information according to the transmission mode of the CCs and the HARQ-ACK timing configured in the each eNB.

In the above UE, the information obtaining module 801 obtains the transmission mode of the CCs configured in the each eNB via RRC singling from the Pcell eNB or obtains the transmission of the CCs configured in the eNB via RRC singling from the Pcell eNB and the Scell eNB.

In the above UE, the resource obtaining module 802 obtains the resources for transmitting the HARQ-ACK feedback information via reading the RRC singling.

Figure 9 is a schematic diagram illustrating structure of the second UE provided by the present disclosure. The UE includes:

a resource obtaining module 901, to obtain resources for transmitting the HARQ-ACK feedback information of different eNBs respectively; and

a transmission module 902, to transmit the HARQ-ACK feedback information of the different eNBs respectively with the resources.

The above resource obtaining module 901 is further to obtain the resources for transmitting the HARQ-ACK feedback information of the different eNBs via the lowest Channel Control Element (CCE) index used by the PDCCH for scheduling the PDSCH of the different eNBs or via a HARQ-ACK Resource Indicator (ARI) domain in the PDCCH scheduling the PDSCH of the different eNBs.

In view of the above, with the method and UE for transmitting the HARQ-ACK feedback information in the Inter-eNB CA system provided by the present disclosure, uniform transmission of the HARQ-ACK feedback information or the separate transmission of the HARQ-ACK feedback information of different eNBs may be implemented in the Inter-eNB CA system via performing relevant configurations at the eNB and UE side.

The foregoing are only embodiments of the present invention. The protection scope of the present invention, however, is not limited to the above description. Any change or substitution, easily occurring to those skilled in the art, should be covered by the protection scope of the present invention.

Claims

A method for transmitting Hybrid-automatic Repeat-Request Acknowledgement (HARQ-ACK) feedback information in an Inter-eNB Carrier Aggregation (Inter-eNB CA) system, comprising:

obtaining, by a User Equipment (UE), HARQ-ACK timing of Component Carriers (CCs) configured in each eNB from a Pcell eNB;

obtaining, by the UE, a transmission mode of the CCs configured in each eNB from the Pcell eNB, or obtaining, by the UE, the transmission mode of the CCs configured in the each eNB from the Pcell eNB and a Scell eNB;

obtaining, by the UE, resources for transmitting the HARQ-ACK feedback information;

transmitting, by the UE, the HARQ-ACK feedback information of Physical Downlink Shared Channel (PDSCH) data corresponding to the each eNB with the obtained resources for transmitting the HARQ-ACK feedback information according to the transmission mode of the CCs and the HARQ-ACK timing configured in the each eNB.
The method according to claim 1, wherein obtaining, by the UE, the transmission mode of the CCs configured in the each eNB from the Pcell eNB comprises:

obtaining, by the UE, the transmission mode of the CCs configured in the each eNB via Radio Resource Control (RRC) singling from the Pcell eNB.
The method according to claim 1, obtaining, by the UE, the transmission mode of the CCs configured in the each eNB from the Pcell eNB and the Scell eNB comprises:

obtaining, by the UE, the transmission mode of the CCs configured in the eNB via RRC singling from the Pcell eNB and the Scell eNB.
The method according to 1, 2 or 3, wherein obtaining, by the UE, the resources for transmitting the HARQ-ACK feedback information comprises: obtaining, by the UE, the resources via reading RRC singling.
The method according to claim 4, wherein when the HARQ-ACK feedback information is transmitted via Physical Uplink Control Channel (PUCCH) format 3, obtaining, by the UE, the resources for transmitting the HARQ-ACK feedback information comprises: obtaining, by the UE, the resources of the PUCCH format 3 via reading the RRC singling.
The method according to claim 5, wherein transmitting the HARQ-ACK feedback information of the PDSCH data from the each eNB comprises: arranging HARQ-ACK feedback information bits of the PDSCH data of the CCs configured in different eNBs with the obtained resources of the PUCCH format 3 from the front to the end according to indexes of the CCs configured in the each eNB.
The method according to claim 5, wherein transmitting the HARQ-ACK feedback information of the PDSCH data from the each eNB comprises: arranging HARQ-ACK feedback information bits of the PDSCH data of the CCs configured in the each eNB with the obtained resources of the PUCCH format 3 respectively according to different starting points and directions.
The method according to claim 7, wherein when the CCs of CA respectively belong to two eNBs, arranging the HARQ-ACK feedback information bits of the PDSCH data of the CCs configured in the each eNB according to the different starting points and directions comprises: arranging the HARQ-ACK feedback information bits of the PDSCH data of the CCs configured in an eNB from the front to the end according to indexes of the CCs and arranging the HARQ-ACK feedback information bits of the PDSCH data of the CCs configured in another eNB from the end to the front according to the indexes of the CCs.
The method according to claim 5, wherein when the CCs of the CA respectively belong to more than two eNBs, transmitting HARQ-ACK feedback information of the PDSCH data from the each eNB comprises: arranging HARQ-ACK feedback information bits of the PDSCH data of the CCs configured in different eNBs with the obtained resources of the PUCCH format 3 from the front to the end according to a specific starting point and indexes of the CCs.
The method according to claim 4, wherein when the HARQ-ACK feedback information is transmitted using PUCCH format 1b with channel selection, obtaining, by the UE, the resources for transmitting the HARQ-ACK feedback information comprises: obtaining, by the UE, two resource of the PUCCH format 1b for each CC via reading the RRC singling.
The method according to claim 10, wherein transmitting the HARQ-ACK feedback information of the PDSCH data from the each eNB comprises: transmitting HARQ-ACK feedback information bits of the PDSCH data from different eNBs on the resources of the PUCCH format 1b using a PUCCH format 1b with the channel selection.
The method according to claim 11, wherein transmitting the HARQ-ACK feedback information bits of the PDSCH data from different eNBs on the resource of the PUCCH format 1b using the PUCCH format 1b with the channel selection comprises:

Generating at most two-bit HARQ-ACK feedback information of the PDSCH data of a CC according to the transmission mode and HARQ-ACK timing of each CC and mapping the generated HARQ-ACK feedback information bits of the PDSCH data of the two CCs using the PUCCH format 1b with the channel selection.
The method according to claim 11, transmitting the HARQ-ACK feedback information bits of the PDSCH data from different eNBs on the resources of the PUCCH format 1b using the PUCCH format 1b with the channel selection comprises:

generating M-bit HARQ-ACK feedback information of the PDSCH data of a CC according to the transmission mode and HARQ-ACK timing of the each CC and mapping the generated HARQ-ACK feedback information bits of the PDSCH data of the two CCs using the PUCCH format 1b with the channel selection; wherein M is the maximum size of bundling windows of the two CCs, the size of the bundling window of the each CC is determined according to the HARQ-ACK timing of the each CC.
The method according to claim 1, wherein before obtaining, by the UE, the HARQ-ACK timing of the CCs configured in the each eNB, the method further comprises:

obtaining, by the Pcell eNB, the HARQ-ACK timing of the CCs configured by the Scell eNB from the Scell eNB.
The method according to claim 1, wherein before the UE obtains the transmission mode of the CCs configured in the each eNB from the Pcell eNB, the method further comprises:

obtaining, by the Pcell eNB, the transmission mode of the CCs configured by the Scell eNB from the Scell eNB.
A User Equipment (UE) adapted to perform the method of one of claims 1 to 15.
A method for transmitting HARQ-ACK feedback information in an Inter-eNB Carrier Aggregation (Inter-eNB CA) system, comprising:

obtaining, by a User Equipment (UE), resources for transmitting the HARQ-ACK feedback information of different eNBs respectively and transmitting the HARQ-ACK feedback information of the different eNBs respectively on the resources.
The method according to claim 17, wherein obtaining, by the UE, the resources for transmitting the HARQ-ACK feedback information of different eNBs respectively comprises: obtaining, by the UE, the resources for transmitting the HARQ-ACK feedback information of the different eNBs via the lowest Channel Control Element (CCE) index used by the PDCCH for schudling the PDSCH of different eNBs or via a HARQ-ACK Resource Indicator (ARI) domain in the PDCCH scheduling the PDSCH of the different eNBs.
A User Equipment (UE) adapted to perform the method of one of claims 17 to 18.