WO2011137741A1 - Data transmission method and system - Google Patents

Abstract

The present invention discloses a data transmission method and system for solving the technical problem of uplink transmission conflict or uplink resource waste in a radio relay network system, without introducing a Relay-Physical Hybrid Automatic Repeat reQuest (HARQ) Indicator CHannel (R-PHICH). In the present invention, a first network element indicates HARQ feedback information to a second network element explicitly and/or implicitly; the second network element transmits data or does not transmit data, according to the HARQ feedback information. The present invention avoids the data transmission conflict and satisfies resource scheduling requirements by means of explicit and/or implicit indication. With no need for an R-PHICH, the overhead for configuring the PHICH using Un interface resources is thus avoided, the signaling overhead for the downlink control channel, the Relay-Physical Downlink Control CHannel (R-PDCCH), of the Un interface is reduced, and the scheduling efficiency and the resource utilization rate is improved.

Description

 Method and system for data transmission

 The present invention relates to the field of communications, and in particular to a method and system for data transmission. Background technique

 E-UTRAN (Evolved Universal Terrestrial Radio Access Network) in the third generation mobile communication LTE (Long Term Evolution) system, supporting hybrid automatic repeat reQuest (Hybrid Automatic Repeat reQuest, HARQ), used to improve the reliability of transmission success.

 The user terminal (UE) has one HARQ entity in the uplink, and the HARQ entity supports multiple HARQ processes, and follows a parallel stop protocol.

 Uplink retransmission is divided into adaptive and non-adaptive retransmission modes. The adaptive retransmission refers to that the transmission parameters required for retransmission need to be indicated by the transmitting end by signaling, that is, the evolved NodeB (eNB or the base station for short) is indicated by the downlink control information (DCI); The transmission means that the transmission parameters required for retransmission are the same as those of the previous transmission, so there is no need for the transmission side to indicate the transmission parameters used for retransmission by the transmitting end. The transmission parameters include: resource block information, transmission power information, redundancy version information, and the like.

 In each subframe in which uplink transmission is possible, the UE determines whether uplink transmission is required according to the following conditions, and whether the uplink transmission is a first transmission, an adaptive retransmission, or a non-adaptive retransmission.

 1, the first pass:

 If there is an uplink grant indicating that the UE performs the first transmission in the subframe, the UE transmits data (ie, the first transmission) according to the uplink grant. The uplink grant indicating that the UE performs the first transmission in the subframe includes the following cases:

1) In the case of Dynamic Scheduling (DS), the UE is under physics A Cell Radio Network Temporary Identity (C-RNTI) is received on the Physical Downlink Control Channel (PDCCH) to indicate an uplink grant that is first transmitted in the subframe. The uplink grant includes the uplink grant. : Resource block information, modulation and coding mode information, New Data Indicator (NDI), redundancy version information, transmission power information, and so on.

 2), in the process of random access, the UE receives a random access response (RAR) message, where the uplink authorization is performed, and the uplink authorization is included in the subframe, where the uplink authorization includes : Resource block information, modulation and coding mode information, redundancy version information, transmission power information, and so on.

 3) In the case of Semi-Persistent Scheduling (SPS), the UE receives the SPS C-RNTI on the PDCCH to indicate the uplink grant in the first transmission of the subframe, or pre-configures the SPS resource indication in the The uplink grant for the uplink transmission of the subframe. The authorization information includes: resource block information, modulation and coding mode information, NDI, and the like.

 During the first transmission, if there is still old data in the HARQ buffer of the HARQ process corresponding to the subframe, the UE replaces the old data in the HARQ buffer with new data, that is, deletes the old data in the HARQ buffer. After the new data is generated, it is placed in the HARQ buffer.

 2, adaptive retransmission:

 If there is an uplink grant indicating that the UE performs retransmission in the subframe, the UE transmits data according to the uplink grant (ie, adaptive retransmission). The uplink grant indicating that the UE performs retransmission in the subframe includes the following cases:

 1) In the case of dynamic scheduling, the UE receives the C-RNTI on the PDCCH to indicate the uplink grant that is retransmitted in the subframe, where the uplink grant includes: resource block information, NDI, and redundancy version information. , transmit power information, etc.

2), in the process of random access, the UE receives a temporary C-RNTI on the PDCCH to indicate an uplink grant that is retransmitted in the subframe; where the uplink grant includes: resource block information, redundancy Remaining version information, transmission power information, etc.

 3) In the case of semi-persistent scheduling, the UE receives the SPS C-RNTI on the PDCCH to indicate an uplink grant that is retransmitted in the subframe. The uplink grant includes: resource block information, a circle, and the like.

 3. Non-adaptive retransmission:

 If there is no uplink grant, the UE is first transmitted or retransmitted in the subframe, and there is still data in the HARQ buffer of the HARQ process corresponding to the subframe, and the UE is in the physical HARQ indicator channel (Physical HARQ Indicator Channel, PHICH). Receiving a NACK (ie, indicating the last transmission failure of the HARQ process), then the UE transmits data according to the uplink grant information used by the last transmission of the HARQ process (ie, non-adaptive retransmission); The uplink grant information includes: resource block information, modulation and coding mode information, and transmit power information.

 Compared to adaptive retransmission, non-adaptive retransmission reduces the signaling overhead of the PDCCH, since the non-adaptive retransmission does not require the sender (i.e., the base station) to transmit the authorization information required for the uplink transmission to the receiver (i.e., the UE). Only the sender (ie, the base station) needs to indicate whether the last transmission of the HARQ process succeeds or not through the PHICH, and if it fails, performs non-adaptive retransmission, and if successful, does not transmit.

 4, do not send data:

 If there is no data in the HARQ buffer of the HARQ process corresponding to the subframe, the UE suspends the HARQ process, that is, the UE does not send data.

 If there is no uplink grant indicating that the UE is first transmitted or retransmitted in the subframe, and there is still data in the HARQ buffer of the HARQ process corresponding to the subframe, and the UE receives an ACK at the PHICH (ie, indicates the HARQ process) The last transmission succeeds, then the UE suspends the HARQ process, ie the UE does not send data, but does not delete the data in the HARQ buffer.

The UE may suspend the HARQ process for the following reasons: 1. The last transmission of the HARQ process is successful, and the base station temporarily does not schedule the UE to continue to send data; 2. The HARQ process The last transmission fails, but the UE decodes the PHICH error and mistakes the NACK as an ACK. The UE considers that the last transmission was successful. In this case, if retransmission is necessary, the base station will retransmit in subsequent scheduling. 3. The HARQ process The last transmission failed, but the base station temporarily does not schedule the retransmission of the UE, so the ACK is sent to the UE through the PHICH.

 Currently, the third generation partner organization, Ji Ge 'J (Third Generation Partnership Projects,

3GPP) introduces the Long-Term Evolution advance (LTE-Advanced) standard. Among them, the wireless relay (Relay) technology is one of the technologies in LTE-Advanced, which aims to expand the coverage of the cell, reduce the dead zone in the communication, balance the load, transfer the service in the hotspot area, and save the terminal (or called the user). The transmit power of the device (User Equipment, UE).

 FIG. 1 is a schematic diagram of a network structure using a wireless relay technology. As shown in FIG. 1, a new relay node/relay station is added between an original donor evolved base station (Door evolved NodeB, DeNB or donor base station) and a UE. (Relay-Node, RN), these new RNs and Donor-eNBs have no wired connection to the transmission network through a wireless connection. The radio link between the Donor-eNB and the RN is called a backhaul link, that is, the Un interface. The radio link between the RN and the UE is called an access link, that is, the Uu interface. . The downlink data arrives at the Donor-eNB first, and then is forwarded to the RN, and the RN transmits the signal to the UE. The uplink is reversed and will not be described here.

 In order to configure the resources of the backhaul link, a Relay-Physical Dedicated Downlink Control Channel (R-PDCCH) and an RN are defined.

R-PDSCH) and the Physical-Dedicated Uplink Shared Channel (R-PUSCH) dedicated to the RN. The R-PDCCH may schedule the RN to receive data on the R-PDSCH in one or more Un downlink subframes, and the R-PDCCH may schedule the RN to transmit data on the R-PUSCH in one or more Un uplink subframes.

The RN-specific PHICH (R-PHICH) is not introduced on the backhaul link because: 1. Backhaul The channel quality of the link is relatively stable, and the probability of retransmission of the backhaul link is low, so

The R-PHICH reduces the signaling overhead very limited, and the advantage is not obvious enough. 2. If the R-PHICH is introduced, then some downlink resources are allocated to the R-PHICH transmission, and the downlink resources are not allowed to transmit the R-PDSCH. That is to say, the DeNB cannot use the downlink resources to schedule the RN to receive data, which affects the downlink service performance of the Un. 3. The DeNB cannot guarantee that the non-adaptive retransmission of Un (referred to by the R-PHICH) does not conflict with the uplink transmission of the Uu. Affects the uplink service performance of Un or Uu. For the above reasons, R-PHICH is not introduced on the backhaul link. On the other hand, the backhaul link is wireless, so it is not guaranteed that the transmission on the backhaul link will be successful. If the RN fails to transmit on the backhaul link, then RN retransmission is required to increase the probability of successful transmission. Considering that the channel quality of the backhaul link is relatively stable, it can be retransmitted with the same resources as the previous transmission and modulation and coding, that is, the backhaul link needs to support non-adaptive retransmission at the same time. When the RN-dedicated PHICH (R-PHICH) is not introduced, the RN cannot know whether the previous transmission was successful or failed according to the RN-specific PHICH (R-PHICH), that is, the RN does not know whether it is non-adaptive. pass. If the RN performs non-adaptive retransmission, it may cause a transmission collision because the base station considers that the RN does not need to retransmit and allocates resources to other network elements. If the RN does not perform non-adaptive retransmission, it may result in wasted resources because the base station considers that the RN needs to retransmit and reserves resources. Summary of the invention

 In view of the above, the main object of the present invention is to provide a data transmission method and system for solving the technical problem of uplink transmission conflict or uplink resource waste without introducing R-PHICH in a wireless relay network system.

 In order to achieve the above object, the technical solution of the present invention is achieved as follows:

 A data transmission method, the method comprising:

The first network element explicitly and/or implicitly indicates hybrid automatic repeat request HARQ feedback information for the second network element; the second network element sends data according to the HARQ feedback information or does not send data. Further, the first network element explicitly indicating the HARQ feedback information for the second network element is specifically:

 After the second network element sends the data, the first network element sends a downlink message to the second network element, where the downlink message indicates that the HARQ feedback information is a positive acknowledgement ACK or a negative acknowledgement NACK.

 Further, the first network element implicitly indicates that the HARQ feedback information is the second network element: the predefined default HARQ feedback information is ACK or NACK;

 In the case of the first transmission or the adaptive retransmission, after the second network element sends the data according to the uplink grant information, if the first network element does not explicitly indicate the HARQ feedback information, the HARQ feedback information is the default. HARQ feedback information.

 Further, the sending, by the second network element, the data according to the HARQ feedback information or not sending the data is: when the uplink authorization information indicating that the second network element sends data is not used, when the HARQ feedback information is ACK The second network element does not send data; when the HARQ feedback information is NACK, the second network element sends data retransmission.

 Further, the downlink message is downlink control information DCI.

 Further, the downlink message indicates that the HARQ feedback information is an ACK or a NACK, specifically:

 Determining, according to different indications of the downlink message, that the HARQ feedback information is an ACK or a NACK; or

 Determining, according to a DCI format of different downlink messages, that the HARQ feedback information is an ACK or a NACK; or

 The HARQ feedback information is indicated as ACK or NACK according to different values of the fields included in the downlink message.

Further, the default HARQ feedback information in the first pass case is the same as or different from the default HARQ feedback information in the case of adaptive retransmission. Further, if the uplink grant information indicating that the second network element sends data is different, the default HARQ feedback information is the same or different.

 The first network element is a base station DeNB, and the second network element is a relay node RN, and the downlink control channel for indicating the HARQ feedback information is a physical downlink control channel R-PDCCH dedicated to the RN, and the data transmission sub-sub The frame is an uplink subframe of the Un interface; or,

 The first network element is a base station eNB, and the second network element is a user terminal UE, where the downlink control channel for indicating the HARQ feedback information is a physical downlink control channel PDCCH, and in the case of frequency division multiplexing FDD, The subframe in which the data is transmitted is all subframes; in the case of time division multiplexing TDD, the subframe in which the data is transmitted is an uplink subframe; or

 The first network element is an RN, and the second network element is a UE, where the downlink control channel for indicating the HARQ feedback information is a PDCCH, and in the case of FDD, the subframe for transmitting data is all subframes; In the case of TDD, the subframe in which data is transmitted is an uplink subframe.

 Based on the foregoing method, the present invention further provides a data transmission system, where the system includes: a first network element, configured to explicitly and/or implicitly indicate HARQ feedback information for a second network element; Transmitting or not transmitting data according to the HARQ feedback information indicated by the first network element.

 The first network element explicitly indicating the HARQ feedback information for the second network element is: after the second network element sends the data, the first network element sends a downlink message to the second network element, where the downlink message indicates the The HARQ feedback information is ACK or NACK.

 The first network element implicitly indicating the HARQ feedback information for the second network element is specifically: the predefined default HARQ feedback information is ACK or NACK; in the case of the first transmission or the adaptive retransmission, in the second After the network element sends data according to the uplink grant information, if the first network element does not explicitly indicate the HARQ feedback information, the HARQ feedback information is default HARQ feedback information.

In the present invention, the DeNB explicitly and/or implicitly provides HARQ feedback information for the RN; Data is transmitted or not transmitted according to the HARQ feedback information. The invention avoids the data transmission conflict by the explicit and/or implicit indication manner, and satisfies the resource scheduling requirement. Since the R-PHICH is not needed, the overhead of configuring the PHICH channel of the Un interface resource is avoided, and the downlink of the Un interface is reduced. The signaling overhead of the control channel R-PDCCH improves scheduling efficiency and resource utilization. DRAWINGS

 1 is a schematic diagram of a network structure using a wireless relay technology;

 Figure 2 is a schematic view of the first embodiment of the present invention;

 FIG. 3 is a schematic diagram of Embodiment 2 of the present invention. detailed description

 The present invention will be further described in detail below with reference to the accompanying drawings.

 The basic idea of the invention is that the first network element explicitly and/or implicitly indicates HARQ feedback information for the second network element; the second network element transmits data or does not transmit data according to the HARQ feedback information. among them,

 The HARQ feedback information refers to a positive acknowledgment (ACK) or a negative acknowledgment (NACK). The explicit indication is specifically: after the second network element sends the data, the first network element sends a downlink message to the second network element, and the downlink message indicates that the HARQ feedback information is an ACK or a NACK.

 The implicit indication is specifically: in the case of the first transmission or the adaptive retransmission, the predefined default HARQ feedback information is ACK or NACK, after the second network element sends data, if the first network element is not explicit Instructing the HARQ feedback information to indicate that the HARQ feedback information is consistent with the default HARQ feedback information. If the first network element explicitly indicates the HARQ feedback information, it indicates that the HARQ feedback information is HARQ feedback information indicated by the first network element by using the downlink message.

The second network element sends data according to the HARQ feedback information or does not send data, specifically: If there is no uplink grant information indicating that the second network element sends data, if the HARQ feedback information is ACK, the second network element does not send data (ie, suspends the HARQ process); if the HARQ feedback information is NACK Then, the second network element sends a data retransmission (ie, non-adaptive retransmission).

 The invention will be described in detail below with reference to the drawings in conjunction with the embodiments.

 Solution 1: Explicitly indicate HARQ feedback information

 After the second network element sends the data, the first network element sends a downlink message to the second network element, where the downlink message indicates that the HARQ feedback information is an ACK or a NACK, where ACK means that the data is successfully sent, and NACK means sending The data failed.

 Further, the downlink message is downlink control information DCI.

 Further, determining, according to one of the following manners, whether the HARQ feedback information indicated by the downlink message is an ACK or a NACK

 1), indicating the HARQ feedback information according to different indications of the downlink message; specifically: when the downlink message indicates an ACK and when the NACK is indicated, indicating that the identifier of the downlink message is different .

 When the downlink message indicates an ACK, the identifier indicating the downlink message is one of the following: C-RNTL SPS C-RNTL Temporary C-RNTI, dedicated C-RNTI.

 When the downlink message indicates a NACK, the identifier indicating the downlink message is one of the following: C-RNTI, SPS C-RNTL temporary C-RNTI, dedicated C-RNTI.

 For example, if the downlink message is indicated by a dedicated C-RNTI, the downlink message indicates that the HARQ feedback information is NACK; if the downlink message is indicated by the C-RNTI, the downlink message indicates that the HARQ feedback information is ACK.

 2), indicating the HARQ feedback information according to a DCI format of different downlink messages; specifically: when the downlink message indicates an ACK and when the NACK is indicated, indicating that the DCI format of the downlink message is different.

In the case that the downlink message indicates an ACK, the DCI format indicating the downlink message is The next one: DCI format 0, dedicated DCI format.

 In the case that the downlink message indicates a NACK, the DCI format indicating the downlink message is one of the following: DCI format 0, dedicated DCI format.

 For example, if the downlink message uses a dedicated DCI format, the downlink message indicates that the HARQ feedback information is NACK; if the downlink message uses DCI format 0, the downlink message indicates that the HARQ feedback information is ACK.

 And indicating, according to different values of the fields included in the downlink message, the HARQ feedback information; specifically: when the downlink message indicates an ACK and a case indicating a NACK, indicating a field of the downlink message The values are different.

 For example, the downlink message includes the value of the following field, and the downlink message indicates that the HARQ feedback information is an ACK; otherwise, the downlink message indicates that the HARQ feedback information is a NACK.

 - "The scheduled PUSCH transmit power control command" (TPC command for scheduled PUSCH) takes the value "00";

 - "Calculate shift DM RS" takes the value "000";

 - "modulation and coding scheme and redundancy version", the value is "11111";

 - "Resource block allocation and hopping resource allocation" takes all values.

For example, the downlink message includes a field indicating the HARQ feedback information. If the field value is 'Γ, the downlink message indicates that the HARQ feedback information is ACK; if the field value is '0, then the The downlink message indicates that the HARQ feedback information is NACK. On the other hand, if the field has a value of '0, the downlink message indicates that the HARQ feedback information is ACK; if the field value is ' Γ , then the downlink message indicates that the HARQ feedback information is NACK. Solution 2: Implicitly indicating HARQ feedback information

 Pre-defined default HARQ feedback information is ACK or NACK;

 In the case of the first transmission or the adaptive retransmission, after the second network element sends the data according to the uplink grant information, if the first network element does not explicitly indicate the HARQ feedback information, the HARQ feedback information is the default. The HARQ feedback information; if the first network element explicitly indicates the HARQ feedback information, the second network element uses the HARQ feedback information indicated by the first network element.

 Further, the default HARQ feedback information depends on at least one of the following:

 1), the default HARQ feedback information is ACK;

 2), the default HARQ feedback information is NACK;

 3) The default HARQ feedback information is different because the data is transmitted first or adaptively.

 Specifically includes one of the following:

 - When the first data is transmitted, the default HARQ feedback information is ACK; when the data is adaptive retransmission, the default HARQ feedback information is NACK;

 - When the transmission data is the first transmission, the default HARQ feedback information is NACK; when the transmission data is adaptive retransmission, the default HARQ feedback information is ACK.

 4) The default HARQ feedback information is different because it indicates that the uplink authorization information of the second network element to send data is different:

 Specifically includes one of the following:

 A, depending on the type of the uplink authorization information:

 The type of the uplink authorization information includes at least one of the following:

 (1) uplink grant information indicated by the C-RNTI;

 (2) uplink authorization information indicated by the SPS C-RNTI;

 (3) uplink authorization information indicated by the temporary C-RNTI;

(4) uplink grant information indicated by the dedicated C-RNTI; (5) Configure (upured) uplink authorization information;

 (6) The uplink authorization information carried in the RAR message.

 For example, when the uplink grant information is indicated by a dedicated C-RNTI, the default HARQ feedback information is NACK, otherwise, the default HARQ feedback information is ACK. For example, when the uplink grant information is indicated by the C-RNTI, the default HARQ feedback information is ACK; when the uplink grant information is indicated by the SPS C-RNTI, the default HARQ feedback information is NACK.

 B. Depending on the content indicating the uplink authorization information:

 For example, the uplink authorization information includes a field indicating default HARQ feedback information. If the value of the field is 'Γ, then the default HARQ feedback information is ACK; if the field value is '0, then the default The HARQ feedback information is NACK. On the other hand, if the field value is '0, then the default HARQ feedback information is ACK; if the field value is 'Γ, then the default HARQ feedback information is NACK.

 The above two schemes of indicating indication and implicit indication may also be combined, such as: explicitly indicating ACK and implicitly indicating NACK, or explicitly indicating NACK and implicitly indicating ACK, or explicitly indicating ACK, NACK, and implicitly indicating NACK Or explicitly indicating ACK, NACK, and implicitly indicating ACK, or explicitly indicating ACK and implicitly indicating ACK, NACK, or explicitly indicating NACK and implicitly indicating ACK, NACK, or explicitly indicating ACK, NACK, and implicit Indicates ACK, NACK.

For example, the NACK is explicitly indicated and the ACK is implicitly indicated. Before the second network element sends data, the first network element indicates that the uplink authorization information transmitted by the second network element is the uplink authorization information indicated by the C-RNTI, and the default is The HARQ feedback information is ACK. After the second network element sends the data, if it is consistent with the default, the first network element does not send the downlink message indication; if it is inconsistent with the default, the first network element sends a downlink message to the second network element to indicate the The HARQ feedback information is a NACK, that is, if the second network element does not receive the downlink message indicating the HARQ feedback information, the HARQ feedback information is considered to be an ACK; conversely, if the indication HARQ feedback information is received According to the indication of the downlink message, the HARQ feedback information is information carried in the downlink message (generally NACK).

 The following embodiment takes a HARQ process as an example. The hybrid automatic repeat request feedback HARQ_FEEDBACK variable is introduced to represent the HARQ feedback information of the MAC PDU in the HARQ buffer.

 Embodiment 1

 2 is a flowchart of Embodiment 1 of the present invention. In this embodiment, the network element 1 notifies the network access control layer protocol data unit (MAC) in the HARQ buffer of the network element 2 by explicit signaling. The HARQ feedback information of the PDU is ACK or NACK. The specific steps of this example are as follows:

 Step 201: After the network element 2 sends the data, it waits for the explicit signaling indication of the network element 1. The network element 2 receives the downlink message sent by the network element 1, and if the downlink message indicates that the HARQ feedback information of the MAC PDU in the HARQ buffer area of the network element 2 is ACK, the process proceeds to step 202. If the downlink message indicates that the HARQ feedback information of the MAC PDU in the HARQ buffer of the network element 2 is NACK, the process proceeds to step 203.

 The downlink message is downlink control information DCI.

 The downlink message indicating the ACK is indicated according to the dedicated C-RNTI, or according to the C-RNTI indication, or according to different identifier indications in different scenarios, such as: according to the C-RNTI indication in the dynamic scheduling, in the SPS scheduling According to the SPS C-RNTI indication, according to the temporary C-RNTI indication during the random access procedure.

 For example, the downlink message is a DCI indicated by a C-RNTI, and the DCI uses a DCI format of 0, and includes the following fields and their values:

 - "The scheduled PUSCH transmit power control command" (TPC command for scheduled PUSCH) takes the value "00";

- "Calculate shift DM RS" takes the value "000"; - "modulation and coding scheme and redundancy version", the value is "11111";

 - "Resource block allocation and hopping resource allocation" takes all values.

 Then, the downlink message indicates an ACK.

 For another example, the downlink message is a DCI indicated by the SPS C-RNTI, and the DCI uses a DCI format 0, and includes the following fields and their values:

 - "The scheduled PUSCH transmit power control command" (TPC command for scheduled PUSCH) takes the value "00";

 - "Calculate shift DM RS" takes the value "000";

 - "modulation and coding scheme and redundancy version", the value is "11111";

 - "Resource block allocation and hopping resource allocation" takes all values.

 - The value of "New Data Indicator" is "Γ.

 Then, the downlink message indicates an ACK.

 The downlink message indicating the NACK is similar to the downlink message indicating the ACK, according to the DCI indicated by the dedicated C-RNTI, or the DCI indicated by the C-RNTI, or the DCI according to different indications in different scenarios. For example, according to the C-RNTI indication in the dynamic scheduling, according to the SPS C-RNTI indication in the SPS scheduling, according to the temporary C-RNTI indication in the random access procedure. The downlink message carries the identifier information indicating the NACK, which is not repeated here.

 Step 202: The network element 2 sets the variable HARQ_FEEDBACK to ACK, and proceeds to step 204. Step 203: The network element 2 sets the variable HARQ_FEEDBACK to NACK, and proceeds to the step.

204.

Step 204: If there is uplink authorization information indicating the first transmission, proceed to step 205; If the uplink authorization information indicating the retransmission is performed, proceed to step 206; if there is no uplink authorization information indicating the first transmission or the retransmission, and the HARQ_FEEDBACK is ACK, proceed to step 207; if there is no uplink authorization information indicating the first transmission or the retransmission, and If HARQ_FEEDBACK is NACK, proceed to step 208.

 The uplink authorization information indicating the first transmission is one of the following:

 1) The network element 1 sends a downlink message to the network element 2, where the uplink authorization information indicating the first transmission is carried. The downlink message is downlink control information DCI or RAR message obtained according to C-RNTI or SPS C-RNTI.

 2) The uplink authorization information carried in the reserved SPS resources.

 The uplink authorization information indicating the retransmission is: the network element 1 sends a downlink message to the network element 2, where the uplink authorization information indicating the retransmission is carried. The downlink message is downlink control information DCI obtained according to C-RNTI or SPS C-RNTI or temporary C-RNTI. At this time, the retransmission is called adaptive retransmission.

 Step 205: The network element 2 sends a first transmission (first transmission) of the data in the HARQ buffer, and proceeds to step 201.

 Step 206: The network element 2 sends a retransmission (adaptive retransmission) of the data in the HARQ buffer, and proceeds to step 201.

 Step 207: The network element 2 does not send data, and proceeds to step 204.

 Step 208: The network element 2 sends a retransmission (non-adaptive retransmission) of the data in the HARQ buffer, and proceeds to step 201.

 Embodiment 2

FIG. 3 is a flowchart of Embodiment 2 of the present invention. In this embodiment, scheme 2 is used to implicitly indicate HARQ feedback information for network element 2, for example: default HARQ feedback information is ACK, if actual HARQ feedback information is NACK. (Inconsistent with the default), the network element 1 notifies the HARQ feedback information of the network element 2 by explicit signaling in the first embodiment. If the actual HARQ is reversed The feed information is ACK (consistent with the default), and the network element 1 optionally informs the HARQ feedback information of the network element 2 by explicit signaling in the first embodiment.

 Step 301: If there is uplink grant information indicating the first transmission, proceed to step 302; if there is uplink grant information indicating retransmission, proceed to step 303; if there is no uplink grant information indicating the first transmission or retransmission, and HARQ_FEEDBACK is ACK , proceed to step 304; if there is no uplink authorization information indicating the first transmission or retransmission, and HARQ_FEEDBACK is NACK, proceed to step 305;

 The uplink grant information indicating the first transmission (or retransmission) may be dedicated uplink grant information in addition to the uplink grant information indicating the first transmission (or retransmission) in the first embodiment. That is, the uplink grant information carried by the downlink message indicated by the dedicated C-RNTI or the uplink grant information of the field indicating the default HARQ feedback information;

 In case the SPS is not supported, the dedicated C-RNTI may be an SPS C-RNTI. Step 302: The network element 2 sets the variable HARQ_FEEDBACK to ACK, and sends the first transmission (first pass) of the data in the HARQ buffer, and proceeds to step 306;

 Step 303: The network element 2 sets the variable HARQ_FEEDB ACK to ACK, and retransmits the data in the HARQ buffer (adaptive retransmission), and proceeds to step 306.

 In this embodiment, whether it is the first transmission or the adaptive retransmission, the variable HARQ_FEEDBACK is set to ACK regardless of the uplink grant information, that is, the default HARQ feedback information is ACK. In addition, the default HARQ feedback information can also be one of the following:

 1), whether it is the first transmission or the adaptive retransmission, regardless of the uplink authorization information, the variable HARQ_FEEDBACK is set to NACK, that is, the default HARQ feedback information is NACK;

 2) The default HARQ feedback information at the first pass is different from the default HARQ feedback information at the time of adaptive retransmission. For example, the first pass defaults to ACK, the retransmission defaults to NACK, or the first pass defaults to NACK, and the retransmission defaults to ACK.

3), the default HARQ feedback information is different because of the uplink authorization information, such as: The authorization information includes a field indicating default HARQ feedback information, and the default HARQ feedback information is different according to the indication of the field; and the default HARQ feedback information is different because of the type of the uplink authorization information.

 The type of the uplink authorization information includes at least one of the following:

 - uplink grant information indicated by the C-RNTI;

 - uplink grant information indicated by the SPS C-RNTI;

 - uplink grant information indicated by the temporary C-RNTI;

 - uplink grant information indicated by a dedicated C-RNTI;

 - Configure (upured) upstream authorization information;

 - Uplink authorization information carried in the RAR message.

 For example, when the uplink grant information is indicated by a dedicated C-RNTI, the default HARQ feedback information is NACK, otherwise, the default HARQ feedback information is ACK. For example, when the uplink grant information is indicated by the C-RNTI, the default HARQ feedback information is ACK; when the uplink grant information is indicated by the SPS C-RNTI, the default HARQ feedback information is NACK.

 Step 304: The network element 2 does not send data, and proceeds to step 301.

 Step 305: The network element 2 sends a retransmission (non-adaptive retransmission) of the data in the HARQ buffer, and proceeds to step 306.

 Step 306: After the network element 2 sends the data, it waits for the explicit signaling indication of the network element 1. If the network element 2 receives the downlink message sent by the network element 1, and indicates that the HARQ feedback information of the MAC PDU in the HARQ buffer of the network element 2 is NACK, the process proceeds to step 307. If the downlink message is not received, proceed to step 301;

 The downlink message is similar to the downlink message indicating the NACK in the first embodiment, and details are not described herein again.

If the HARQ_FEEDBACK in steps 302, 303 is set to NACK, then step 306 includes at least a downlink message indicating an ACK. Optionally, if the network element 2 receives the downlink message sent by the network element 1, where the HARQ feedback information of the MAC PDU in the HARQ buffer of the network element 2 is indicated as ACK, the network element 2 sets the variable HARQ_FEEDBACK to ACK. Then proceed to step 301.

 Step 307: The network element 2 sets the variable HARQ_FEEDBACK to NACK, and proceeds to the step.

301.

 In summary, the following three situations are included:

 1. In case the network element 1 only explicitly indicates ACK:

 If the network element 2 receives the explicit signaling indicating the ACK, the previous transmission is considered successful; if the network element 2 does not receive the explicit signaling, the previous transmission is considered to have failed.

 2. In case the network element 1 only explicitly indicates NACK:

 If the network element 2 receives the explicit signaling indicating the NACK, it considers that the previous transmission failed; if the network element 2 does not receive the explicit signaling, it considers that the previous transmission failed.

 3. In the case where the network element 1 explicitly indicates ACK/NACK:

 If the network element 2 receives the explicit signaling indicating the ACK, the previous transmission is considered successful; if the network element 2 receives the explicit signaling indicating the NACK, the previous transmission is considered to have failed.

 NE 1 and NE 2 have the following combinations:

 (1) The network element 1 is the base station DeNB, and the network element 2 is the relay node RN, and the downlink control channel used is the R-PDCCH, and the subframe in which the data is transmitted is the uplink subframe of Un;

 (2) The network element 1 is the base station eNB, the network element 2 is the user terminal UE, and the downlink control channel used is the PDCCH. In the case of frequency division multiplexing (FDD), the subframe in which the data is transmitted is all subframes; In the case of time division multiplexing (TDD), the subframe in which data is transmitted is an uplink subframe;

 (3) The network element 1 is a relay node RN, the network element 2 is a user terminal UE, and the downlink control channel is a PDCCH. In the case of FDD, a subframe in which data is transmitted is all subframes, and in the case of TDD, a subframe in which data is transmitted is Uplink subframe.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications to the invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim A data transmission method, characterized in that the method comprises:  The first network element explicitly and/or implicitly indicates hybrid automatic repeat request HARQ feedback information for the second network element; the second network element transmits data or does not transmit data according to the HARQ feedback information.  The method according to claim 1, wherein the method for the first network element to explicitly indicate the HARQ feedback information for the second network element is:  After the second network element sends the data, the first network element sends a downlink message to the second network element, where the downlink message indicates that the HARQ feedback information is a positive acknowledgement ACK or a negative acknowledgement NACK.  The method according to claim 1, wherein the method for the first network element to implicitly indicate HARQ feedback information for the second network element is:  Pre-defined default HARQ feedback information is ACK or NACK;  In the case of the first transmission or the adaptive retransmission, after the second network element sends the data according to the uplink grant information, if the first network element does not explicitly indicate the HARQ feedback information, the HARQ feedback information is the default. HARQ feedback information.  The method according to claim 2 or 3, wherein the method for the second network element to send data according to the HARQ feedback information or not to send data is:  In the case that there is no uplink grant information indicating that the second network element sends data, when the HARQ feedback information is ACK, the second network element does not send data; when the HARQ feedback information is NACK, the second network element sends Data retransmission.  The method according to claim 2, wherein the downlink message is downlink control information DCI. The method according to claim 2, wherein the method for indicating that the HARQ feedback information is ACK or NACK is: Determining, according to different indications of the downlink message, that the HARQ feedback information is an ACK or a NACK; or  Determining, according to a DCI format of different downlink messages, that the HARQ feedback information is an ACK or a NACK; or  The HARQ feedback information is indicated as ACK or NACK according to different values of the fields included in the downlink message.  The method according to claim 3, wherein the default HARQ feedback information in the first transmission case is the same as or different from the default HARQ feedback information in the case of adaptive retransmission.  The method according to claim 3, wherein, in the case that the uplink grant information indicating that the second network element sends data is different, the default HARQ feedback information is the same or different.  9. The method of claim 1 wherein:  The first network element is a donor base station DeNB, and the second network element is a relay node RN, and the downlink control channel for indicating the HARQ feedback information is a physical downlink control channel R-PDCCH dedicated to the RN, and the data is transmitted. The subframe is an uplink subframe of the Un interface; or,  The first network element is an evolved base station eNB, and the second network element is a user terminal UE, where the downlink control channel for indicating the HARQ feedback information is a physical downlink control channel PDCCH, in the case of frequency division multiplexing FDD The subframe in which the data is transmitted is all subframes; in the case of time division multiplexing TDD, the subframe in which the data is transmitted is an uplink subframe; or,  The first network element is a relay node RN, and the second network element is a UE, and the downlink control channel for indicating the HARQ feedback information is a PDCCH. In the case of FDD, a subframe for transmitting data is all children. Frame; In the case of TDD, the subframe in which data is transmitted is an uplink subframe.  10. A data transmission system, comprising: a first network element, configured to explicitly and/or implicitly indicate HARQ feedback information for the second network element, where the second network element is configured to send data according to the HARQ feedback information indicated by the first network element or not send data. The system according to claim 10, wherein the method for the first network element to explicitly indicate HARQ feedback information for the second network element is:  After the second network element sends the data, the first network element sends a downlink message to the second network element, where the downlink message indicates that the HARQ feedback information is an ACK or a NACK.  The system according to claim 10, wherein the method for implicitly indicating HARQ feedback information for the second network element by the first network element is:  Pre-defined default HARQ feedback information is ACK or NACK;  In the case of the first transmission or the adaptive retransmission, after the second network element sends the data according to the uplink grant information, if the first network element does not explicitly indicate the HARQ feedback information, the HARQ feedback information is the default. HARQ feedback information.  The system according to claim 11 or 12, wherein the method for the second network element to transmit data or not to transmit data according to the HARQ feedback information is:  In the case that there is no uplink grant information indicating that the second network element sends data, when the HARQ feedback information is ACK, the second network element does not send data; when the HARQ feedback information is NACK, the second network element sends Data retransmission.  The system according to claim 11, wherein the method for indicating that the HARQ feedback information is ACK or NACK is:  Determining, according to different indications of the downlink message, that the HARQ feedback information is an ACK or a NACK; or  Determining, according to a DCI format of different downlink messages, that the HARQ feedback information is an ACK or a NACK; or  The HARQ feedback information is indicated as ACK or NACK according to different values of the fields included in the downlink message. 15. The system according to claim 12, wherein the default HARQ feedback information in the case of the first transmission is the same as or the default HARQ feedback information in the case of adaptive retransmission. Same.  The system according to claim 12, wherein the default HARQ feedback information is the same or different when the uplink grant information indicating that the second network element sends data is different.  17. The system of claim 10, wherein:  The first network element is a DeNB, and the second network element is an RN, and the downlink control channel for indicating the HARQ feedback information is an R-PDCCH, and the subframe for transmitting data is an uplink subframe of the Un interface; or  The first network element is an eNB, and the second network element is a UE, where the downlink control channel for indicating the HARQ feedback information is a PDCCH, and in the case of FDD, the subframe for transmitting data is all subframes; In the case of TDD, the subframe in which the data is transmitted is an uplink subframe; or,  The first network element is an RN, and the second network element is a UE, where the downlink control channel for indicating the HARQ feedback information is a PDCCH, and in the case of FDD, the subframe for transmitting data is all subframes; In the case of TDD, the subframe in which data is transmitted is an uplink subframe.