WO2010115307A1

WO2010115307A1 - Transmission method of relay link, base station and relay system

Info

Publication number: WO2010115307A1
Application number: PCT/CN2009/071219
Authority: WO
Inventors: 孙晓婷; 常宁娟; 彭炎
Original assignee: 华为技术有限公司
Priority date: 2009-04-10
Filing date: 2009-04-10
Publication date: 2010-10-14
Also published as: CN102282908A

Abstract

The present invention discloses a transmission method of relay link, a base station and a relay system. The method includes the following steps: obtaining the conditions of receiving the data transmitted by relay node RN; according to the receiving conditions, transmitting ACK/NACK feeding information to the RN, and transmitting uplink scheduling instruction to the RN, which indicates the RN to transmit data to the base station according to the uplink scheduling instruction. HARQ reliable transmission on the network using relay technology is realized by the embodiment of the present invention.

Description

Relay link transmission method, base station and relay system

The present invention relates to mobile communication technologies, and in particular, to a transmission method of a relay link, a base station, and a relay system. Background technique

In the process of the development of broadband and mobile networks, the 3rd Generation Partnership Program (3GPP) proposed a Long Term Evolution (LTE) solution for mobile access networks. Evolved Universal Mobile Telecommunication System Territorial Radio Access Network (E-UTRAN), and proposed System Architecture Evolution (SAE) scheme on the mobile core network, namely Evolved Packet Core, EPC). The E-UTRAN uses a single-layer structure consisting of only Evolved NodeBs (eNBs). Before the relay technology is introduced, the User Equipment (UE) directly exchanges information with the eNB. After the introduction of the relay technology, the UE can exchange information with the eNB through a relay node (RN).

After the introduction of the relay technology, it is necessary to solve the Hybrid Automatic Repeat reQuest (HARQ) problem of the network using the relay technology. Summary of the invention

The embodiments of the present invention provide a method for transmitting a relay link, a base station, and a relay system, which solve the HARQ problem of the network using the relay technology.

An embodiment of the present invention provides a method for transmitting a relay link, including:

Obtaining the reception of data sent by the relay node RN;

Transmitting ACK/NACK feedback information to the RN according to the receiving situation, and reporting the The RN sends an uplink scheduling instruction, instructing the RN to transmit data to the base station according to the uplink scheduling instruction. The embodiment of the invention further provides a transmission method of a relay link, including:

Receiving ACK/NACK feedback information sent by the relay node RN, where the ACK/NACK feedback information is carried in a medium access control protocol data unit MAC PDU message, where the ACK/NACK feedback information indicates data sent by the RN to the base station Receiving situation;

And transmitting, according to the ACK/NACK feedback information, data and a downlink scheduling instruction to the RN, where the downlink scheduling instruction indicates a manner of sending data sent by the base station.

An embodiment of the present invention provides a base station, including:

An obtaining module, configured to acquire a receiving condition of data sent by the relay node RN;

The feedback module is configured to send ACK/NACK feedback information to the RN according to the receiving situation, and send an uplink scheduling instruction to the RN, instructing the RN to transmit data to the base station according to the uplink scheduling instruction.

The embodiment of the invention further provides a base station, including:

a receiving module, configured to receive ACK/NACK feedback information sent by the relay node RN, where the ACK/NACK feedback information is carried in a media access control protocol data unit MAC PDU message, where the ACK/NACK feedback information indicates the RN The reception of data transmitted by the base station;

And a sending module, configured to send, according to the ACK/NACK feedback information, data and a downlink scheduling instruction to the RN, where the downlink scheduling instruction indicates a manner of sending data sent by the base station.

An embodiment of the present invention provides a relay system, including: a base station and a relay device that mutually transmit data and ACK/NACK feedback information, where the base station is configured to send a scheduling instruction to a relay device, where the relay device is used by Transmitting data to the base station according to the scheduling instruction.

According to the foregoing technical solution, the embodiment of the present invention implements HARQ reliable transmission of the network using the relay technology by using ACK/NACK feedback information and scheduling commands between the base station and the RN. DRAWINGS

1 is a schematic flow chart of a method according to a first embodiment of the present invention; 2 is a schematic flow chart of a method according to a second embodiment of the present invention;

3 is a schematic flow chart of a method according to a third embodiment of the present invention;

4 is a schematic structural diagram of Embodiment 1 of an ACK/NACK feedback information sending method according to the present invention; FIG. 5 is a schematic structural diagram of Embodiment 2 of an ACK/NACK feedback information sending method according to the present invention; FIG. 6 is an ACK/NACK feedback according to the present invention. FIG. 8 is a schematic structural diagram of Embodiment 4 of an ACK/NACK feedback information sending method according to the present invention; FIG. 8 is a schematic structural diagram of Embodiment 5 of an ACK/NACK feedback information sending method according to the present invention; FIG. 9 is a schematic structural diagram of a base station according to a fourth embodiment of the present invention; FIG.

FIG. 10 is a schematic structural diagram of a base station according to a fifth embodiment of the present invention; FIG.

FIG. 11 is a schematic structural diagram of a relay system according to a sixth embodiment of the present invention. detailed description

The technical solution of the present invention will be further described in detail below through the accompanying drawings and embodiments. FIG. 1 is a schematic flowchart of a method according to a first embodiment of the present invention, including:

Step 11: The base station acquires the reception status of the data sent by the RN.

Step 12: The base station sends an ACK/NACK feedback message to the RN according to the receiving situation, and sends an uplink scheduling instruction to the RN, instructing the RN to transmit data to the base station according to the uplink scheduling instruction. In the prior art, the UE and the base station perform HARQ retransmission in the uplink synchronization mode, that is, after the UE sends data to the base station, the base station feeds back ACK/NACK information to the UE according to the receiving situation, and after receiving the NACK information, the UE is fixed. The sequential uplink subframe retransmits the data. Taking the HARQ retransmission of 4 processes as an example, the retransmission timing can be as shown in Table 1:

Table 1

In Table 1, the first uplink subframe is used to transmit the retransmission data of the first process, and the second uplink subframe is used to transmit the retransmission data of the second process, and the third uplink subframe (Table 1 Corresponding to the sixth The subframe is used to transmit the retransmission data of the third process, and the fourth uplink subframe (corresponding to the seventh subframe in Table 1) is used to transmit the retransmission data of the fourth process, and so on. That is, in the prior art, the HARQ retransmission order is fixed. However, after the relay node is introduced between the UE and the base station, according to the frame structure design, some subframes can only be used for the access link, and the rest can be used for the relay link, if still according to Table 1. The fixed order may not implement HARQ retransmission. For example, the first subframe in Table 1 is configured to be applied only to the access link, but not to the relay link. Then, between the relay node and the base station is It is not possible to use the timing of Table 1 for HARQ retransmission.

To this end, in this embodiment, the base station sends an uplink scheduling instruction to the RN, and schedules an instruction problem on the uplink.

In this embodiment, the ACK/NACK feedback information and the uplink scheduling instruction are transmitted between the base station and the RN, and the HARQ problem of the base station and the RN can be solved.

The following describes in detail a more detailed uplink transmission method between the base station and the RN:

2 is a schematic flowchart of a method according to a second embodiment of the present invention. The uplink method for uplink HARQ retransmission of a relay link includes:

Step 201: The RN sends new transmission data to the eNB.

Step 202: If the eNB does not successfully receive, send a NACK to the RN.

Step 203: The eNB sends an uplink scheduling instruction (UL grant) to the RN, and the new data indication (NDI) in the uplink scheduling instruction does not change. In the upstream scheduling instruction, NDI can be divided into two cases of invariant and flipping (for example, 1, 0 respectively), NDI does not mean that data needs to be retransmitted, and NDI flip means that new data needs to be transmitted (new transmission).

Step 204: The RN retransmits data to the eNB.

Step 205: If the eNB does not successfully receive, send a NACK to the RN, and assume that the NACK is lost.

Step 206: The eNB sends an uplink scheduling instruction (UL grant) to the RN, and the NDI in the uplink scheduling instruction does not change. Step 207: The RN retransmits the data to the eNB.

Step 208: If the eNB successfully receives the data, send an ACK to the RN, and assume that the ACK is lost.

Step 209: The eNB sends an uplink scheduling instruction (UL grant) to the RN. If the eNB successfully receives the data, it does not need to retransmit, and new data is needed, that is, the NDI inversion in the uplink scheduling instruction.

Step 210: The RN sends the newly transmitted data to the eNB.

Step 211: If the eNB successfully receives the data, send an ACK to the RN.

Step 212: The eNB sends an uplink scheduling instruction (UL grant) to the RN, where the NDI is reversed. Step 213: The RN sends the newly transmitted data to the eNB, if it is lost.

Step 214: The eNB sends a NACK to the RN because no data is received.

Step 215: The eNB sends an uplink scheduling instruction (UL grant) to the RN, and the NDI in the uplink scheduling instruction does not change.

Step 216: The RN retransmits data to the eNB.

Step 217: If the eNB successfully receives the data, send an ACK to the RN.

When the asynchronous HARQ retransmission mode is used, each retransmission needs to be scheduled through a Physical Downlink Control Channel (PDCCH). Therefore, this embodiment proposes a new UL grant format. The Downlink Control Information (DCI format) format (DCI format) may include at least a Modulation and Coding Style (MCS) index, a Frequency Division Duplexing (FDD) or a Time Division Duplex mode. (Time Division Duplexing, TDD) HARQ process number, NDI, UL index, where the MCS mode index can be selected as 5 bits (bits), the FDD HARQ process number can be selected as 3 bits, and the TDD HARQ process number It can be selected as 4bits, NDI can be selected as lbit, and UL index can be selected as 2bits.

In this embodiment, the uplink mode is used in the uplink mode, that is, the uplink grant command (UL grant) is used, and the subframe position of the RN that needs to be retransmitted or newly transmitted may be specified in the uplink scheduling command, so that the existing subframe can be avoided. Synchronization may cause problems such as inapplicability. The above describes the uplink-asynchronous HARQ mode. Similarly, the downlink between the base station and the RN can also be asynchronous, as follows:

3 is a schematic flowchart of a method according to a third embodiment of the present invention, and the asynchronous manner for the downlink HARQ of the relay link includes:

Step 301: The eNB sends a new transmission message to the RN.

Step 302: If the RN does not successfully receive, send a NACK to the eNB.

Step 303: The RN sends a downlink scheduling instruction (DL assignment) to the eNB, and the NDI in the downlink scheduling instruction does not change.

Step 304: The eNB retransmits data to the RN.

Step 305: The RN sends a NACK to the eNB, assuming that the NACK is lost.

Step 306: The eNB sends a downlink scheduling instruction (DL assignment) to the RN, and the NDI in the downlink scheduling instruction does not change.

Step 307: The eNB retransmits the data to the RN.

Step 308: If the RN successfully receives the data, send an ACK to the eNB, assuming that the ACK is lost. Step 309: The eNB sends a downlink scheduling instruction (DL assignment) to the RN, where the NDI is unchanged.

Step 310: The eNB retransmits data to the RN.

Step 311: If the RN successfully receives data, send an ACK to the eNB.

Step 312: The eNB sends a downlink scheduling instruction (DL assignment) to the RN, where the NDI is inverted.

Step 313: The eNB sends the newly transmitted data to the RN if it is lost.

Step 314: The RN sends a NACK to the eNB.

Step 315: The eNB sends a downlink scheduling instruction (DL assignment) to the RN, and the NDI in the scheduling instruction does not change.

Step 316: The eNB retransmits the data.

Step 317: If the eNB successfully receives the data, send an ACK to the RN. In this embodiment, the asynchronous mode is used in the downlink mode, that is, the downlink scheduling instruction (DL assignment) is used, and the subframe position of the RN that needs to be retransmitted or newly transmitted may be specified in the downlink scheduling instruction, so that the existing position can be avoided. Synchronization may cause problems such as inapplicability.

The retransmission problem in the HARQ is described above, that is, the embodiment of the present invention provides an HARQ uplink retransmission in an asynchronous manner. For the feedback problem in HARQ, the embodiment of the present invention also gives a solution. In the prior art, each physical hybrid automatic repeat request indicator channel (PHICH) includes one UE's ACK/NACK information, and Binary Phase Shift Keying (BPSK) is used. modulation. Each PHICH is spread by 4 times orthogonal code, 3 times repeated, and transmitted on 12 resource elements (Resource Element, RE). In the Long Term Evolution (LTE) system, the uplink and downlink links use synchronous HARQ feedback. Specifically, after receiving data in a certain downlink subframe, the UE needs to send an ACK in the corresponding uplink subframe. /NACK, For FDD, if the UE has downlink data transmission on the Physical Downlink Shared Channel (PDSCH) in the n-4th frame, the uplink ACK/NACK is transmitted on the nth frame. For TDD, the timing is shown in Table 2:

Table 2

Up and down configuration sub-frame ( Subframe n )

(UL-DL 0 1 2 3 4 5 6 7 8 9 Configuration )

0 - - 6 - 4 - - 6 - 4

1 - - 7,6 4 - - - 7,6 4 -

2 - - 8,7,4,6 - - - - 8,7,4,6 - -

3 - - 7,6,11 6,5 5,4 - - - - -

4 - - 12,8,7,11 6,5,4,7 - - - - - -

5 - - TBD - - - - - - -

6 - - 7 7 5 - - 7 7 - After transmitting data in an uplink subframe, the UE needs to receive the PHICH in the corresponding downlink subframe. For FDD, k _PHICH = 4, for TDD, k _PHICH timing is shown in Table 3:

table 3

Since the transmission between the UE and the base station is changed after the introduction of the relay node in the network, in the multi-hop network that introduces the relay node, according to the frame structure design, some subframes can only be used for the access link, and the rest It is only possible to use the relay link, so that the synchronous HARQ feedback timing in the existing protocol is the same as the uplink synchronous HARQ retransmission, and is not satisfied on the relay link. One of the solutions is uplink, mode 1, and asynchronous ACK/NACK feedback, and the ACK/NACK feedback information of the relay link is placed in a Media Access Control (MAC) control element. in.

The MAC control element includes a HARQ process number and ACK/NACK feedback information, and is transmitted on the PDSCH and a Physical Uplink Shared Channel (PUSCH). Its package format can include the following two forms:

1) FIG. 4 is a schematic structural diagram of Embodiment 1 of an ACK/NACK feedback information sending method according to the present invention. Referring to FIG. 4, ACK/NACK feedback information of multiple HARQ processes are separately placed, each into The ID number is followed by the ACK/NACK information corresponding to the process number.

2) FIG. 5 is a schematic structural diagram of Embodiment 2 of a method for transmitting ACK/NACK feedback information according to the present invention. Referring to Figure 5, the ACK/NACK feedback information of multiple HARQ processes is placed in a centralized manner and mapped in the form of an index.

The MAC control element may be indicated by a reserved field in a Logical Channel Identifier (LCID) in a Protocol Data Unit (PDU) subheader. The reserved field in the LCID may be as shown in Table 4. (DL_SCH) or Table 5 (UL_SCH). The MAC control element where the ACK/NACK feedback information is located may be one or more of the reserved fields 01011-11011 (DL_SCH) or 01011-11001 (UL_SCH).

LCID indication.

Table 4

Index (index) LCID value (value)

00000 Common Control Channel (CCCH)

00001-01010 ID of the logical channel

01011-11011 Reserved (Reserved)

11100 User Equipment Conflict Resolution Identifier (UE Contention Resolution Identity )

11101 Timing Advance

11110 Discontinuous Receive Command (DRX Command)

11111 Filling ( Padding ) Table 5

Index (index) LCID value (value)

00000 Common Control Channel (CCCH)

00001-01010 ID of the logical channel

01011-11001 Reserved (Reserved) 11010 Power Command Messages (Power Headroom Report)

11011 User Intra-Cell Identification (C-RNTI)

11100 Truncated Cache Status 4 Truncated BSR

11101 Short Cache Status Report ( Short BSR )

11110 long cache status report ( Long BSR )

11111 Padding mode 2, asynchronous ACK/NACK feedback format, and the ACK/NACK feedback of the relay link is placed in a special MAC PDU.

The MAC PDU includes a HARQ process number and ACK/NACK feedback, and is transmitted on the PDSCH and the PUSCH. Its package format can include the following two forms:

1) FIG. 6 is a schematic structural diagram of Embodiment 3 of a method for transmitting ACK/NACK feedback information according to the present invention. Referring to Figure 6, the ACK/NACK feedback information of multiple HARQ processes is separately placed, and each process number is followed by the ACK/NACK information corresponding to the process number.

2) FIG. 7 is a schematic structural diagram of Embodiment 4 of a method for transmitting ACK/NACK feedback information according to the present invention. Referring to Figure 7, the ACK/NACK feedback information of multiple HARQ processes is placed in a centralized manner and mapped according to the index.

In the above two manners, the ACK/NACK information is fed back in an asynchronous manner, and the ACK/NACK information can be fed back in a synchronous manner in the embodiment of the present invention. In the prior art, the ACK/NACK feedback information is in a synchronous manner, and the HARQ process number does not need to be carried. Therefore, the ACK/NACK feedback information in the prior art is packaged into a message at the physical layer due to the physical layer. The message is small. If multiple ACK/NACK information needs to be fed back in the same subframe, multiple ACK/NACK information is combined and then transmitted in a binding or multiplexing manner. If a downlink subframe is in error, it is tied. All downlink subframes that are fed back need to be retransmitted. This practice will undoubtedly increase the amount of data. To this end, the embodiment provides a synchronization mode, but the ACK/NACK feedback information is packaged in the MAC layer, that is, the ACK/NACK feedback information is carried in the MAC PDU message. Mode 3: Synchronous ACK/NACK feedback format. FIG. 8 is a schematic structural diagram of Embodiment 5 of an ACK/NACK feedback information sending method according to the present invention. Referring to FIG. 8 , the ACK/NACK feedback of the relay link is inserted into the tail of the MAC PDU, and the HARQ process ID is not included. The order of ACK/NACK is strictly corresponding to the corresponding uplink/downlink data subframe number. This MAC PDU format is suitable for synchronous ACK/NACK feedback. The time slot of the MAC PDU inserted by the ACK/NACK and the time slot of the uplink/downlink receiving data are strictly corresponding according to the convention.

The foregoing embodiments respectively describe a method for performing HARQ retransmission in an asynchronous manner, and a HARQ feedback method using an asynchronous method and a synchronous method, and solving a HARQ problem of a network using a relay technology.

A person skilled in the art can understand that all or part of the steps of implementing the above method embodiments may be completed by using hardware related to program instructions, and the foregoing program may be stored in a computer readable storage medium, and the program is executed when executed. The method includes the steps of the foregoing method embodiments; and the foregoing storage medium includes: a medium that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

FIG. 9 is a schematic structural diagram of a base station according to a fourth embodiment of the present invention, which includes an obtaining module 91 and a feedback module 92. The obtaining module 91 is configured to obtain the receiving condition of the data sent by the relay node RN. The feedback module 92 is connected to the obtaining module 91, and configured to send ACK/NACK feedback information to the RN according to the receiving situation, and The RN sends an uplink scheduling instruction, instructing the RN to transmit data to the base station according to the uplink scheduling instruction. The information, or, has the means for carrying the ACK/NACK feedback information in the MAC PDU message for transmission.

In this embodiment, the HARQ reliable transmission of the network using the relay technology is realized by the ACK/NACK feedback information and the scheduling instruction between the base station and the RN.

FIG. 10 is a schematic structural diagram of a base station according to a fifth embodiment of the present invention, including a receiving module 101 and a sending module 102. The receiving module 101 is configured to receive ACK/NACK feedback information sent by the RN, where The ACK/NACK feedback information is carried in the MAC PDU message, and the ACK/NACK feedback information indicates the receiving condition of the data sent by the RN to the base station; the sending module 102 is connected to the receiving module 101, and configured to use the ACK/NACK feedback information according to the ACK/NACK feedback information. Sending data and a downlink scheduling instruction to the RN, where the downlink scheduling instruction indicates a manner of transmitting data sent by the base station.

The receiving module 101 is configured to receive the ACK/NACK feedback information sent by the RN, and receive the uplink data of the RN, where the ACK/NACK feedback information is carried in the MAC PDU message, and the sending module 102 is configured to send the data and the downlink scheduling instruction to the RN. And feeding back ACK/NACK information to the RN;

FIG. 11 is a schematic structural diagram of a relay system according to a sixth embodiment of the present invention, including a base station 111 and a relay device (RN) 112 that mutually transmit data and ACK/NACK feedback information, where the base station 111 is configured to send to a relay device. And scheduling the instruction, the relay device 112 is configured to send data to the base station according to the scheduling instruction.

The base station 111 and the relay device 112 are specifically configured to transmit the ACK/NACK feedback information in an asynchronous manner, or specifically, to transmit the ACK/NACK feedback information in the MAC PDU message in a synchronous manner.

It should be noted that the above embodiments are only intended to illustrate the technical solutions of the present invention and are not to be construed as limiting the embodiments of the present invention. Modifications or equivalents of the technical solutions of the present invention may be made without departing from the spirit and scope of the technical solutions of the present invention.

Claims

Rights request

A method for transmitting a relay link, comprising:

Obtaining the reception of data sent by the relay node RN;

And sending, according to the receiving situation, ACK/NACK feedback information to the RN, and sending an uplink scheduling instruction to the RN, instructing the RN to transmit data to the base station according to the uplink scheduling instruction.

2. The method according to claim 1, wherein the sending the ACK/NACK feedback information comprises: transmitting the ACK/NACK feedback information in an asynchronous manner.

The method according to claim 2, wherein the sending the ACK/NACK feedback information in an asynchronous manner comprises: carrying a plurality of hybrid automatic repeat requests in the medium access control protocol data unit MAC PDU message ACK/NACK feedback information of the HARQ process.

The method according to claim 3, wherein the carrying the ACK/NACK feedback information of the multiple HARQ processes in the MAC PDU message comprises: carrying the ACK of the multiple HARQ processes in the MAC control unit of the MAC PDU message. NACK feedback information.

The method of claim 3 or 4, wherein the ACK/NACK feedback information carrying the multiple HARQ processes comprises: separately placing ACK/NACK feedback information of multiple HARQ processes; or, placing multiple HARQs The ACK/NACK feedback information of the process is placed in a centralized manner.

The method according to claim 1, wherein the sending the ACK/NACK feedback information comprises: carrying the ACK/NACK feedback information in a downlink subframe corresponding to the data sent by the RN by using a synchronization manner In the MAC PDU message.

The method according to claim 1, wherein the uplink scheduling instruction comprises a modulation coding mode MCS, a HARQ process number, a new data indication NDI, and an uplink UL index.

8. A method for transmitting a relay link, comprising:

Sending data and a downlink scheduling instruction to the RN according to the ACK/NACK feedback information, The downlink scheduling instruction indicates a manner of sending data sent by the base station.

The method according to claim 8, wherein the ACK/NACK feedback information is carried in the MAC PDU message, including: in an asynchronous manner, carrying a plurality of hybrid automatic repeat request HARQ processes in the MAC PDU message ACK/NACK feedback information.

The method of claim 9, wherein the carrying the ACK/NACK feedback information of the multiple HARQ processes comprises: separately placing the ACK/NACK feedback information of the multiple HARQ processes; or, The ACK/NACK feedback information is placed in a centralized manner.

A base station, comprising:

The base station according to claim 11, wherein the feedback module is specifically configured to send the ACK/NACK feedback information in an asynchronous manner, or have an ACK/NACK method for detecting synchronization. The feedback information is carried in the Medium Access Control Protocol Data Unit MAC PDU message.

13. A base station, comprising:

a receiving module, configured to receive ACK/NACK feedback information sent by the relay node RN, where the ACK/NACK feedback information is carried in a media access control protocol data unit MAC PDU message, where the ACK/NACK feedback information indicates the RN And a sending module, configured to send, according to the ACK/NACK feedback information, data and a downlink scheduling instruction to the RN, where the downlink scheduling instruction indicates a sending manner of data sent by the base station.

A relay system, comprising: a base station and a relay device that mutually transmit data and ACK/NACK feedback information, wherein the base station is configured to send a scheduling instruction to the relay device, where the relay device is used to Transmitting data to the base station according to the scheduling instruction.

The system according to claim 14, wherein the base station and the relay device have The ACK/NACK feedback information is transmitted in an asynchronous manner, or is used to carry the ACK/NACK feedback information in a medium access control protocol data unit MAC PDU message in a synchronous manner.