WO2010124605A1

WO2010124605A1 - Method and apparatus for data transmission in relay system

Info

Publication number: WO2010124605A1
Application number: PCT/CN2010/072198
Authority: WO
Inventors: 王立波; 张文健; 潘学明; 肖国军; 沈祖康
Original assignee: 大唐移动通信设备有限公司
Priority date: 2009-04-27
Filing date: 2010-04-26
Publication date: 2010-11-04
Also published as: CN101873609B; CN101873609A

Abstract

A method for data transmission in relay system, includes that: modulation information corresponding to the data of a physical downlink shared channel (PDSCH) is transmitted via a physical downlink control channel (PDCCH) to a user equipment (UE) served by a type 2 relay station; a preset beam-forming processing is performed on the data of the PDSCH, and the processed data of the PDSCH and the dedicated pilot corresponding to the beam-forming processing are transmitted to the UE; an evolved Node B (eNB) directly transmits the common reference signal (CRS) used to demodulate the PDCCH to the UE, and the type 2 relay station does not transmit the CRS to the UE. The present invention also provides concrete structures of the eNB and the type 2 relay station. The application of the present invention can implement concrete data transmission in the system in which the type 2 relay station is introduced.

Description

Data transmission method and device in relay system

The present invention relates to a relay technology in a communication system, and more particularly to a data transmission method and apparatus in a relay system. Background of the invention

In the LTE-A system, a Relay Node (RN) is introduced to improve system throughput and increase network coverage. The following cartridge is called a relay. The network structure of the LTE-A system that specifically introduces the relay node is shown in Figure 1.

The eNB is connected to the core network (CN) through a wired interface, and the RN is connected to the eNB through a wireless interface, and the UE is connected to the RN or the eNB through the wireless interface. Both the RN and the eNB can provide services for the UE. The UE served by the RN is called a relay UE (R-UE), and the UE directly served by the eNB is called a macro UE.

There are currently two types of relays, type 1 and type 2, and the definition of type 2 is given in LTE-A. Specifically, the Type 2 relay does not have a separate cell ID, does not create any new cell, and can serve the R8 UE; and, at least for the R8 UE, the Type 2 relay is transparent, and for the version higher than 8, For UEs, Type 2 relays are also preferably transparent.

Although LTE-A gives the above definition of Type 2, it does not give a specific data transmission method and flow for the relay and the eNB, and with the UE. Summary of the invention

In view of the above, the present invention provides a data transmission method and apparatus in a relay system, which can implement specific data transmission in a system that introduces a Type 2 relay. In order to achieve the above object, the present invention adopts the following technical solutions:

A data transmission method in a relay system, comprising:

The eNB sends the PDSCH data to be sent to a UE and its corresponding scheduling information to at least one relay serving the UE;

The eNB directly sends the common reference signal CRS and the PDCCH carrying the scheduling information of the PDSCH data to the UE.

Preferably, the manner in which the eNB sends the PDSCH data and the corresponding scheduling information to the relay is: sending, in the current downlink time slot, PDSCH data that needs to be sent to the UE in the next downlink time slot to the middle The scheduling information of the PDSCH data in the downlink time slot is sent to the relay through the PDCCH, and the scheduling information of the PDSCH data in the next downlink time slot is sent to the relay through the PDCCH or the PDSCH;

The manner in which the eNB sends the corresponding scheduling information of the PDSCH data to the UE is: in the next downlink time slot, the eNB sends the scheduling information of the PDSCH data in the next downlink time slot directly to the PDCCH through the PDCCH. The UE.

Preferably, the manner in which the eNB sends the PDSCH data and the corresponding scheduling information to the relay is: in the current downlink time slot, the eNB sends the PDSCH data that needs to be sent to the UE in the next downlink time slot to The relay sends the scheduling information of the PDSCH data in the downlink time slot to the relay through the PDCCH, and sends the downlink N times downlink time slots in the current frame to the relayed PDSCH data in the current frame. The scheduling information of the N downlink time slots is sent to the relay through the PDCCH or the PDSCH. In any one of the last N downlink time slots in the current frame, the eNB needs to send the downlink time slot n+1 to the relay. Transmitting, by the UE, PDSCH data to the relay;

The manner in which the eNB sends the corresponding scheduling information of the PDSCH data to the UE is: in any one of the last N downlink time slots in the current frame, the eNB needs to send the downlink time slot n to the UE. Scheduling information of PDSCH data in downlink slot n, The PDCCH is directly sent to the UE.

Preferably, the method further comprises: the eNB transmitting the PDSCH data transmitted for the first time and the dedicated pilot corresponding to the beamforming process performed on the PDSCH data to the UE.

Preferably, in a downlink time slot in which the PDSCH data is first transmitted, the eNB directly sends the PDSCH data and scheduling information in the downlink time slot to the UE and the relay, and The dedicated pilot is directly sent to the UE, and the scheduling information of the PDSCH data on the downlink time slot for retransmitting the PDSCH data is sent to the relay through the PDCCH or the PDSCH.

Preferably, the method further comprises: receiving, by the eNB, information that the PDSCH data that is fed back by the UE fails to be demodulated, and after receiving the information, sending the PDSCH data and the dedicated pilot that need to be retransmitted to the UE.

Preferably, in the downlink time slot in which the PDSCH data is first sent, the eNB directly sends the PDSCH data and its scheduling information in the downlink time slot to the UE and the relay, and The dedicated pilot is directly sent to the UE, and the scheduling information of the PDSCH data on the downlink time slot for retransmitting the PDSCH data is sent to the relay through a PDCCH or a PDSCH;

On the downlink time slot in which the PDSCH data is retransmitted, the eNB directly sends the scheduling information of the PDSCH data that is first transmitted in the downlink time slot to the UE by using a PDCCH; The PDSCH data and the dedicated pilot are transmitted to the UE.

A data transmission method in a relay system, comprising:

The relay receives the PDSCH data and the corresponding scheduling information sent by the eNB, and sends the dedicated pilot and the received PDSCH data to the UE of the relay service according to the scheduling information, where the UE sends the UE to the UE. PDSCH data passes through a preset beam shaping The relay does not transmit a common reference signal CRS to the UE.

Preferably, the manner in which the relay receives the PDSCH data and the corresponding scheduling information from the eNB is: in the current time slot, the relay receives the PDSCH data and scheduling information in the downlink time slot;

The manner in which the relay sends the PDSCH data and the dedicated pilot to the UE includes: forwarding, in the next downlink time slot of the current time slot, the PDSCH data received by the current downlink time slot to the The UE transmits the dedicated pilot to the UE.

Preferably, the manner in which the relay receives the PDSCH data and the corresponding scheduling information from the eNB is: receiving, in the current downlink time slot, the PDSCH data that needs to be sent to the UE in the next downlink time slot, and receiving the Scheduling information of the downlink time slot of the PDSCH data; and receiving scheduling information of the N downlink time slots of the PDSCH data sent to the PD downlink data in the current N downlink time slots in the current frame; The downlink time slot n of the N downlink time slots, the PDSCH data that needs to be sent to the UE in the downlink time slot n+1; the manner in which the relay sends the PDSCH data and the dedicated pilot to the UE includes: Any one of the last N downlink slots in the current frame, the relay forwards the PDSCH data received by the downlink slot n-1 to the UE, and sends the dedicated pilot to the UE Said UE.

Preferably, after receiving the demodulation failure information fed back by the UE, the relay performs an operation of transmitting PDSCH data and a DRS to the UE.

An eNB in a relay system includes:

a relay interface unit, configured to send PDSCH data to be sent to the UE served by the relay in the system to the relay, and send scheduling information corresponding to the PDSCH data to the relay by using a PDCCH; Scheduling information and transmitting a common reference signal CRS to the UE. Preferably, the relay interface unit is further configured to deliver the PDSCH data and the scheduling information to multiple relays that serve the UE.

Preferably, the UE interface unit, when first transmitting the PDSCH data, is further configured to send the PDSCH data, scheduling information corresponding to the PDSCH data, and a dedicated pilot DRS to the UE.

Preferably, the UE interface unit is further configured to receive information about the PDSCH data demodulation failure reported by the UE, and after receiving the information, to use the PDSCH data to correspond to the PDSCH data. The scheduling information and the DRS are sent to the UE again.

A relay in a relay system, including:

An eNB interface unit, configured to receive PDSCH data sent by an eNB connected to the eNB, and scheduling information corresponding to the PDSCH data carried by the PDCCH;

The UE interface unit is configured to send the received PDSCH data and the dedicated pilot DRS to the UE that is serving the UE, and does not send the common reference signal CRS to the UE; wherein the PDSCH data is subjected to preset beamforming processing. The dedicated pilot is pilot information corresponding to the beamforming process.

It can be seen from the above technical solution that, in the present invention, the eNB needs to transmit to the physical downlink shared channel (PDSCH) data of the UE served by the type 2 relay (hereinafter referred to as type 2 R-UE), and forwards it to the type 2 relay. Type 2 R-UE; At the same time, the eNB directly sends a common reference signal (CRS) to the UE, and the type 2 relay does not send the CRS to the type 2 R-UE to avoid interference to the macro UE; to ensure the solution of the PDSCH data by the UE Tune, set type 2 R-UE work in pass In the transmission mode 7, the eNB performs beamforming on the PDSCH data corresponding to the transmission mode, and sends a dedicated pilot (DRS) corresponding to the beamforming to the type 2 R-UE by using the type 2 relay. In this way, data transmission between the Type 2 relay and the Type 2 R-UE and the eNB can be realized, and the interference to the macro UE is effectively controlled. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a network structure of an LTE-A system that introduces a relay node. Mode for carrying out the invention

In order to make the objects, technical means and advantages of the present invention more comprehensible, the present invention will be further described in detail with reference to the accompanying drawings.

In the LTE-A system, downlink service data is transmitted on the channel PDSCH. Therefore, the lower service data transmitted on the PDSCH is referred to as PDSCH data. The PDSCH data transmitted in each downlink time slot corresponds to the corresponding scheduling information, and the physical downlink control channel (PDCCH) is used to carry the scheduling information. Therefore, the specific bearer mode of the PDSCH data needs to be determined according to the scheduling information carried on the PDCCH. The demodulation of scheduling information on the PDCCH needs to be performed according to a Common Reference Signal (CRS). In summary, if the UE needs to correctly receive the PDSCH data, it first needs to receive the CRS, use the CRS to demodulate the scheduling information on the PDCCH, and then determine the bearer mode of the PDSCH data, and then demodulate the PDSCH data.

The eNB needs to follow the foregoing procedure to demodulate the PDSCH data sent by the eNB. That is, the eNB needs to deliver the CRS and the PDCCH to the macro UE. In the system where the type 2 relay is located, if the type 2 relay sends the CRS to the type 2 R-UE, the eNB may interfere with the CRS sent by the eNB to the macro UE, which affects the macro UE's reception of the CRS, thereby affecting Demodulation of PDCCH and PDSCH.

Based on the above analysis, considering that the main purpose of Type 2 relay is to increase the throughput of the system, To control the interference of the Type 2 relay to the macro UE, in the data transmission method of the present invention, the eNB sends the CRS to the Type 2 R-UE, and the Type 2 relay does not deliver the CRS to the Type 2 R-UE. At the same time, the type 2 relay does not deliver the CRS to the type 2 R-UE, and the PDSCH data is sent to the type 2 R-UE through the type 2 relay, and the demodulation problem of the PDSCH data needs to be considered. In the present invention, in order for the Type 2 R-UE to utilize the relayed signal, the Type 2 R-UE is configured as a dedicated transmission mode 7, and the DRS is used for demodulation of the PDSCH data. The transmission mode 7 defines a beamforming processing mode, and the DRS is a pilot after the defined beamforming process. Therefore, the type 2 R-UE can directly demodulate the PDSCH by using the DRS. The specific beamforming process can be configured independently at the eNB and the relay, as long as the time-frequency resources used by the eNB and the relay and the debug coding mode (MCS) are the same.

In summary, the method for transmitting data on the network side in the present invention includes: transmitting scheduling information corresponding to PDSCH data to a Type 2 R-UE through a PDCCH; performing PD beam data on a preset beam shaping process, and processing the PDSCH data The PDSCH data and the DRS corresponding to the beamforming process are sent to the UE; the eNB directly sends the common reference signal CRS to the UE, and the Type 2 relay does not send the CRS to the UE. The foregoing transmission method is formed by combining the data transmission method of the eNB and the data transmission method of the type 2 relay, and plays a common role for transmitting data to the type 2 R-UE.

Corresponding to the foregoing sending method, when performing data reception on the UE side, it is required to set the UE to work in the transmission mode 7; when performing data reception, the UE receives the CRS from the eNB, demodulates the scheduling information carried by the PDCCH, and receives according to the demodulation result. The PDSCH data processed by the preset beamforming is used to demodulate the received PDSCH data by using the received DRS corresponding to the preset beamforming process.

In the foregoing data transmission, the scheduling information carried by the PDCCH may be that the eNB forwards the type 2 R-UE by using the type 2 relay, that is, between the eNB and the type 2 relay, between the type 2 relay and the type 2 R-UE. There is a PDCCH, or it may be sent directly by the eNB. Type 2 R-UE, that is, there is a PDCCH between the eNB and the Type 2 R-UE, and there is no PDCCH between the Type 2 relay and the Type 2 R-UE.

The CRS needs to be demodulated by using the CRS. Therefore, the CRS and the PDCCH are preferably corresponding. If the PDCCH channel received by the UE does not match the received CRS information, the demodulation performance of the PDCCH signal may be degraded. Therefore, preferably, the scheduling information carried by the PDCCH is directly sent by the eNB to the Type 2 R-UE.

If the Type 2 relay does not transmit CRS and PDCCH, then the trunk will not send a broadcast channel (PBCH), or even a primary and secondary synchronization signal (PSS/SSS). At the same time, the manner in which the eNB sends the CRS to the Type 2 R-UE is the same as the existing implementation, and is not described here.

When there is no PDCCH between the UE and the type 2 relay, the data transmission method performed on the eNB side in the present invention includes: the eNB sends the PDSCH data to be sent to a UE and its corresponding scheduling information to the UE. At least one type 2 relay; and transmitting the CRS and the PDCCH carrying the corresponding scheduling information of the PDSCH data to the UE directly.

The data transmission method performed on the type 2 relay side includes: the type 2 relay receiving eNB sends the PDSCH data and its corresponding scheduling information, and according to the scheduling information, sends the DRS and the received PDSCH data to the type. 2 relayed UE; the Type 2 relay does not send a common reference signal CRS to the UE. The PDSCH data sent by the type 2 relay to the UE is data that has undergone preset beamforming processing, and the beamforming processing operation may be performed at the eNB or may be performed at the type 2 relay; the transmitted DRS is Pilot information corresponding to the beamforming process.

Next, specific embodiments of the present invention will be described in detail. For convenience of description, the data transmission method of the eNB and the data transmission method of the type 2 relay provided in the present invention and the corresponding receiving method are introduced together. The description is made by taking an example in which there is no PDCCH between the type 2 relay and the type 2 R-UE. And, in the following embodiments, the issued The PDSCH data is subjected to beamforming processing as an example in the eNB. In fact, the beamforming processing can also be performed in the Type 2 relay.

Embodiment 1:

In this embodiment, the implementation manner of transmitting PDSCH data to the UE every time is described without considering the case of retransmission.

In this embodiment, when the PDSCH data needs to be sent to a certain type of R-UE, the eNB forwards the PDSCH data after the beamforming process by using at least one type 2 relay serving the type 2 R-UE. For the type 2 R-UE; the eNB directly transmits scheduling information corresponding to the PDSCH data to the Type 2 R-UE through the PDCCH; and all Type 2 relays that perform the PDSCH data forwarding, corresponding to the beamforming processing DRS is sent to the type 2 R-UE;

The Type 2 R-UE directly receives scheduling information corresponding to the PDSCH data carried by the PDCCH from the eNB, and receives PDSCH data and DRS from the Type 2 relay, and combines all received PDSCH data, and all received DRSs are received. The combining is performed, and the combined PDRS data is demodulated by the combined DRS.

In the foregoing data transmission mode, a group of PDSCH data is to be sent through two downlink time slots, and one or more Type 2 relays can be used for forwarding when performing PDSCH data forwarding. In the following, two specific transmission examples of the above transmission modes are given, and the transmission is performed by using one or more Type 2 relays. The following is an example of performing the delivery of a set of PDSCH data by using two downlink time slots.

Example 1: Using a type 2 relay RN A for the type 2 R-UE (hereinafter referred to as UE B) for relaying, specifically includes:

Step 101: In the downlink time slot 1, the eNB sends the scheduling information of the PDSCH data and the PDSCH data in the downlink time slot 1 and the downlink time slot 2 to the RN A.

The data of the PDSCH sent to the RN A is scheduled by the system in one downlink. The PDSCH data is sent to the UE B in the time slot; the UE B is the UE served by the RN A; the eNB sends the downlink time slot 1 scheduling information to the RN A by: transmitting the downlink time slot on the PDCCH using the C-RNTI of the RN A The scheduling information in the system, where the C-RNTI is an identifier of a node (including a relay and a UE) in the system, and the entire network is unique;

The manner in which the eNB sends the downlink time slot 2 scheduling information to the RN A may be: using the relayed C-RNTI transmission on the PDCCH, or the eNB may also use the PDSCH between the eNB and the RN A to transmit the downlink time slot 2 scheduling information. .

Step 102: In the downlink time slot 2, the eNB sends the scheduling information of the PDSCH data in the downlink time slot 2 to the UE B, and the RN A sends the PDSCH data and the DRS to the UE B. The UE determines the bearer mode of the PDSCH data by using the received scheduling information, and The received PDSCH data is demodulated using DRS.

The mode in which the eNB sends the scheduling information of the downlink time slot 2 to the UE B is: The eNB transmits the scheduling information of the downlink time slot 2 by using the C-RNTI of the UE B on the PDCCH.

Example 2: The eNB determines to perform data transmission by using multiple relays serving Type 2 R-UE (hereinafter referred to as UE B), and the multiple relays constitute a relay set C. The specific data transmission process includes: Step 201, In downlink slot 1, the eNB transmits PDSCH data and scheduling information of PDSCH data in downlink slot 1 and downlink slot 2 to each relay in relay set C.

The data of the PDSCH sent to the RN A is the PDSCH data that is sent by the system to the UE B in one downlink time slot; the UE B is the UE served by the RN A; and the eNB relays each relay in the relay set C. The method for transmitting the downlink slot 1 scheduling information is: the eNB sends the scheduling information in the downlink slot 1 by using the C-RNTI of each relay on the PDCCH;

The manner in which the eNB sends the downlink slot 2 scheduling information to each relay in the relay set C may be: the eNB uses the C-RNTI transmission of each relay on the PDCCH, or may use the eNB and each relay. The PDSCH transmits the scheduling information of the downlink slot 2. Step 202: In the downlink time slot 2, the eNB sends scheduling information of the PDSCH data in the downlink time slot 2 to the UE B, and each relay in the relay set C sends the PDSCH data and the DRS to the UE B. The UE determines by using the received scheduling information. The bearer mode of the PDSCH data combines all received PDSCH data, combines all received DRSs, and demodulates the combined PDSCH data by using the combined DRS.

The manner in which the eNB sends the scheduling information of the downlink slot 2 to the UE B is the same as that in the first example. In the second example, the PDSCH data is transmitted by using a plurality of relays, so that a certain combining gain can be realized, and the reception performance of the PDSCH data can be improved.

In the above two examples, only two downlink time slots are taken as an example for description. In fact, the same applies to multiple downstream time slots. The Type 2 R-UE receives PDSCH data and DRS only from the Type 2 relay and receives only the PDCCH and CRS from the eNB.

Specifically, in three or more (including three) downlink time slots, the downlink time slot may be nested one by one, that is, in the downlink time slot 2, the eNB not only delivers the downlink time slot 2 scheduling information to the UE, but also Each relay delivers PDSCH data and scheduling information that needs to be sent to the UE in the downlink time slot 3, and starts transmission of the next group of PDSCH data. In the downlink time slot 3, the eNB sends scheduling information of the next group of PDSCH data to the UE. The relay may also directly send the next set of PDSCH data and DRS to the UE; the UE still receives scheduling information from the eNB in each downlink time slot, and receives PDSCH data and DRS from the relay to perform data demodulation. In this way, each downlink time slot is nested one by one, and multiple sets of PDSCH data are transmitted.

Or, in the downlink time slot of three or more (including three), the scheduling information may be transmitted in batches, that is, in the downlink time slot 2, the eNB not only delivers the downlink time slot 2 scheduling information to the UE, but also sends the downlink scheduling information to each relay. The scheduling information of the PDSCH data that needs to be transmitted to the UE in the downlink time slots 3, 4... is prepared, and the transmission of the following groups of PDSCH data is prepared.

In more detail, in the current downlink time slot, the eNB sends the PDSCH data that needs to be sent to the UE in the next downlink time slot to the Type 2 relay, and adjusts the PDSCH data in the downlink time slot. The degree information is sent to the Type 2 relay through the PDCCH, and the downlink N times slots in the current frame (because the eNB can only send the scheduling information of the current frame to the relay) need to send the PDSCH data of the Type 2 relay to the present The scheduling information of the N downlink time slots in the frame is sent to the type 2 relay; in any one of the last N downlink time slots in the current frame, the eNB needs to send the downlink time slot n+1 to the The PDSCH data of the UE is sent to the Type 2 relay, and the scheduling information of the PDSCH data that needs to be sent to the UE in the downlink time slot n in the downlink time slot n is directly sent to the UE through the PDCCH, and the Type 2 relay will be The PDSCH data received by the downlink slot n-1 is forwarded to the UE, and the DRS is also sent to the UE. The UE still receives scheduling information from the eNB in each downlink time slot, and receives PDSCH data and DRS from the relay to perform data demodulation.

The continuous transmission of PDSCH data can be realized by the above method of batch transmission scheduling information.

In the following two embodiments, the implementation of transmitting PDSCH data to the UE will be described in consideration of the case of retransmission.

Embodiment 2:

In this embodiment, when it is required to deliver PDSCH data to a certain type of R-UE, the eNB directly transmits the first transmitted PDSCH data to the type 2 R-UE and the type 2 relay serving the UE; When the PDSCH data is retransmitted, the Type 2 relay transmits the PDSCH data that needs to be retransmitted to the Type 2 R-UE.

The type 2 R-UE receives the first transmitted PDSCH data directly from the eNB, and performs demodulation. After the demodulation fails, the demodulation failure information is fed back to the type 2 relay, and the retransmitted PDSCH data is received from the type 2 relay. , demodulation.

In the above data transmission mode, the first delivery and retransmission of a group of PDSCH data needs to be completed through two downlink time slots. In the following, a specific transmission example of the foregoing transmission mode is given, where the first delivery and retransmission of a group of PDSCH data is completed by using two downlink time slots. The example is explained.

Example 3: Using a type 2 relay RN A is a type of service 2 R-UE (hereinafter referred to as UE B) performs relay forwarding, including:

Step 301: In the downlink time slot 1, the eNB sends the data of the PDSCH and the scheduling information of the PDSCH data in the downlink time slot 1 and the downlink time slot 2 to the RN A, and sends the PDSCH data and the PDSCH data to the UE B in the downlink time slot 1 Scheduling information and DRS.

The PDSCH data sent by the eNB to the RN A and the UE B is the same, and is the PDSCH data that the system schedules to send to the UE B in one downlink time slot;

The manner in which the eNB sends the downlink slot 1 scheduling information to the UE B is: transmitting the scheduling information in the downlink slot 1 by using the C-RNTI of the UE B on the PDCCH;

When the eNB sends the downlink slot 1 scheduling information to the RN A, it may use the C-RNTI of the RN A to transmit on the PDCCH. Alternatively, the scheduling information of the downlink slot 1 may be sent by using the C-RNTI of the UE B on the PDCCH. The RN A stores the C-RNTI of the UE B. Therefore, the RN A can parse the scheduling information, so that the downlink slot 1 scheduling information can be sent to the RN A and the UE B together;

The manner in which the eNB sends the downlink time slot 2 scheduling information to the RN A is the same as that in the first embodiment, and details are not described herein again.

Step 302: The UE receives the scheduling information of the downlink time slot 1 carried by the PDCCH from the eNB, determines the bearer mode of the PDSCH data received from the eNB, and demodulates the received PDSCH data by using the DRS received from the eNB. If the demodulation fails, Then, the demodulation failure information is fed back to the RN A.

Step 303: In the downlink time slot 2, the eNB sends the scheduling information of the PDSCH data in the downlink time slot 2 to the UE B, and the RN A transmits the PDSCH data and the DRS to the UE B again. The UE determines the bearer mode of the PDSCH data by using the received scheduling information. The DRS is used to demodulate the retransmitted PDSCH data. The manner in which the eNB sends the scheduling information to the UE B is the same as that in the first example, and details are not described herein again.

At this point, the first transmission and retransmission of the PDSCH data is achieved. In this embodiment, the PDSCH data is directly sent by the eNB to the UE when it is first transmitted, and is sent to the UE by the Type 2 relay during retransmission.

Embodiment 3:

In this embodiment, when the PDSCH data needs to be sent to a certain type of R-UE, the eNB directly sends the first-transmitted PDSCH data to the type 2 R-UE and the type 2 relay serving the UE; When the PDSCH data is retransmitted, the eNB and the Type 2 relay transmit the PDSCH data that needs to be retransmitted to the Type 2 R-UE.

The UE directly receives the first transmitted PDSCH data from the eNB, and performs demodulation. After the demodulation fails, the retransmitted PDSCH data and the DRS are received from the Type 2 relay and the eNB; the UE combines the retransmitted PDSCH data and performs demodulation. .

In the above data transmission mode, the first delivery and retransmission of a set of PDSCH data needs to be completed through two downlink time slots. In the following, a specific transmission example of the foregoing transmission mode is given. The first delivery and retransmission of a group of PDSCH data is performed by using two downlink time slots as an example.

Example 4: Using a Type 2 Relay RN A is a type of service 2 R-UE (hereinafter referred to as UE B) for relaying, including:

Step 401: In the downlink time slot 1, the eNB sends the data of the PDSCH and the scheduling information of the PDSCH data in the downlink time slot 1 and the downlink time slot 2 to the RN A, and sends the PDSCH data and the PDSCH data to the UE B in the downlink time slot 1 Scheduling information and DRS.

The specific transmission method is the same as that in the first example, and will not be described here.

Step 402: The UE receives scheduling information of the downlink time slot 1 carried by the PDCCH from the eNB, determines a bearer mode of the PDSCH data received from the eNB, and uses the DRS received from the eNB. The received PDSCH data is demodulated, and if the demodulation fails, the demodulation failure information is fed back to the RN A.

Step 403: In the downlink time slot 2, the eNB sends the scheduling information of the PDSCH data in the downlink time slot 2 to the UE B, and the eNB and the RN A retransmit the PDSCH data and the DRS to the UE B. The UE determines the bearer of the PDSCH data by using the received scheduling information. The method combines the PDSCH data received from the eNB and the PDSCH data received from the RN A in the downlink time slot 2, and combines the DRS received from the eNB in the downlink time slot 2 with the DRS received from the RN A, and uses the combined DRS. The combined PDSCH data is demodulated.

At this point, the first transmission and retransmission of the PDSCH data is achieved. In this embodiment, the PDSCH data is directly sent to the UE by the eNB when the first transmission is performed, and is transmitted to the UE by the eNB and the Type 2 relay during retransmission, and the UE combines the received retransmission data and demodulates. In the manner of this embodiment, the PDSCH data is sent by both the eNB and the Type 2 relay, so that the UE can obtain the combining gain when retransmitting, thereby improving the receiving performance of the PDSCH data.

The above two cases and the third example take the two downlink time slots as an example to illustrate the data transmission mode under retransmission. In fact, the same applies to more downlink time slots. Specifically, one-down downlink slot nesting and batch transmission may be adopted. The manner of the scheduling information and the like, the manner of nesting the downlink time slot and the batch transmission scheduling information one by one is the same as that in the first embodiment, and details are not described herein again.

The above is a specific implementation manner of the data transmission method proposed by the present invention after the type 2 relay is introduced. In the above method, the process in which the eNB sends the CRS to the UE is the same as the existing one. Therefore, when describing the specific implementation, it is not mentioned. In fact, in the entire data transmission method, the eNB always sends the CRS to the UE according to the existing manner. .

Corresponding to the above method, the present invention also provides an eNB and type 2 relay specific structure for implementing the corresponding method. The Type 2 R-UE can be used in the existing structure and set to operate in Transmission Mode 7.

Specifically, the eNB corresponding to the first embodiment includes a type 2 relay interface unit and a UE. Port unit

The Type 2 relay interface unit is configured to send PDSCH data to be sent to the Type 2 relay of the Type 2 relayed UE in the system, and send the PDSCH to the Type 2 relay through the PDCCH. Corresponding scheduling information of the data; according to the corresponding scheduling information, and sending a common reference signal CRS for demodulating the PDCCH to the UE.

The type 2 relay corresponding to the first embodiment includes an eNB interface unit and a UE interface unit. The eNB interface unit is configured to receive PDSCH data sent by an eNB connected to the eNB and a scheduling corresponding to the PDSCH data carried by the PDCCH. information.

The UE interface unit is configured to send the DRS and the received PDSCH data to the UE that is serving the UE, and does not send the common reference signal CRS to the UE. The PDSCH data sent to the UE is subjected to a preset beamforming process, and the dedicated pilot is pilot information corresponding to the beamforming process.

When the foregoing eNB is applied to the method for forwarding data for a UE by using multiple Type 2 relays as shown in Example 2, the Type 2 relay interface unit is further used for relaying multiple Type 2 to the serving UE. Send PDSCH data and corresponding scheduling information.

The eNB corresponding to the second embodiment also includes a type 2 relay interface unit and a UE interface unit, where the type 2 relay interface unit is configured to send PDSCH data to be sent to the UE served by the type 2 relay in the system to Type 2 relaying, and transmitting scheduling information corresponding to the PDSCH data to the Type 2 relay through a PDCCH;

The UE interface unit sends the PDSCH data and the DRS to the UE when transmitting the PDSCH data for the first time, and sends the scheduling information corresponding to the PDSCH data to the UE by using the PDCCH when transmitting and retransmitting the PDSCH data for the first time, and A common reference signal CRS for demodulating the PDCCH is transmitted. The PDSCH data sent to the UE is pre-processed. The beamforming process is performed, and the dedicated pilot is pilot information corresponding to the beamforming process. The type 2 relay corresponding to the second embodiment includes an eNB interface unit and a UE interface unit. The eNB interface unit is configured to receive PDSCH data sent by an eNB connected to the eNB and a scheduling corresponding to the PDSCH data carried by the PDCCH. Information; the PDSCH data is processed by a preset beamforming process.

a UE interface unit, configured to send the received PDSCH data and the dedicated pilot DRS corresponding to the beamforming process to the UE that is serving the UE, and not send the common reference signal CRS to the UE; The PDSCH data demodulation failed information, and after receiving the information, is used to send the PDSCH data, the scheduling information corresponding to the PDSCH data, and the DRS to the UE again. The PDSCH data sent to the UE is subjected to preset beamforming processing, and the dedicated pilot DRS is pilot information corresponding to the beamforming processing.

The eNB corresponding to the third embodiment also includes a type 2 relay interface unit and a UE interface unit, where the type 2 relay interface unit is configured to send PDSCH data to be sent to the UE served by the type 2 relay in the system to Type 2 relaying, and transmitting scheduling information corresponding to the PDSCH data to the Type 2 relay through a PDCCH;

The UE interface unit, when transmitting the PDSCH data for the first time, sends the PDSCH data and the DRS to the UE, and sends scheduling information corresponding to the PDSCH data to the UE by using the PDCCH; After receiving the information, the PDSCH data, the scheduling information corresponding to the PDSCH data, and the DRS are sent to the UE again; and is further configured to send a common reference signal CRS for demodulating the PDCCH to the UE. . The PDSCH data sent to the UE is subjected to a preset beamforming process, and the dedicated pilot DRS is pilot information corresponding to the beamforming process.

The type 2 relay corresponding to the third embodiment is the same as the type 2 relay structure corresponding to the third embodiment, and details are not described herein again. The foregoing is the specific structure and corresponding functions of the eNB and the Type 2 relay provided by the present invention after the Type 2 relay is introduced. Among them, only the structure involved in the present invention has been described, and the units that need to complete other inherent functions in the eNB and the Type 2 relay are not described. The specific implementation is the same as the existing one. The UE can adopt the existing implementation structure, and will not be described here.

It can be seen from the foregoing specific implementation manner of the present invention that in the LTE-A system that introduces type 2 relay, the present invention provides a specific manner for data transmission between an eNB, a type 2 relay, and a type 2 R-UE, which can be implemented. data transmission. In addition, in the transmission mode, the eNB sends a CRS to the UE, and the Type 2 relay does not send the CRS to the UE, thereby avoiding pilot interference for the macro UE. Meanwhile, the UE only receives the PDCCH from the eNB. There is no PDCCH between the UE and the Type 2 relay, thereby reducing the overhead of the PDCCH.

The above are only the preferred embodiments of the present invention and are not intended to limit the scope of protection of the present 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 in a relay system, the method includes: the eNB transmitting, to the at least one relay serving the UE, PDSCH data to be sent to a UE and corresponding scheduling information;

2. The transmitting method according to claim 1, wherein

The manner in which the eNB sends the PDSCH data and the corresponding scheduling information to the relay is: sending, in the current downlink time slot, PDSCH data that needs to be sent to the UE in the next downlink time slot to the relay, The scheduling information of the PDSCH data in the downlink time slot is sent to the relay through the PDCCH, and the scheduling information of the PDSCH data in the next downlink time slot is sent to the relay through the PDCCH or the PDSCH;

The transmitting method according to claim 1, wherein the eNB sends the PDSCH data and the corresponding scheduling information to the relay in a manner that: in a current downlink time slot, when the eNB is going to the next downlink The PDSCH data to be sent to the UE is sent to the relay, and the scheduling information of the PDSCH data in the downlink time slot is sent to the relay through the PDCCH, and the next N downlink time slots in the current frame are required. The scheduling information of the N downlink time slots of the PDSCH data sent to the relay in the current frame is sent to the relay through the PDCCH or the PDSCH; any one of the last N downlink time slots in the current frame is the downlink time slot n The eNB sends the PDSCH data that needs to be sent to the UE in the downlink time slot n+1 to the relay; the manner in which the eNB sends the corresponding scheduling information of the PDSCH data to the UE is: The downlink time slot n of any one of the last N downlink time slots in the frame, the eNB sends the scheduling information of the PDSCH data of the downlink time slot n to the UE in the downlink time slot n, and directly sends the scheduling information to the UE.

The transmitting method according to claim 1, wherein the method further comprises: the eNB transmitting the first transmitted PDSCH data and the dedicated pilot DRS corresponding to the beamforming processing performed on the PDSCH data to the local Said UE.

The transmission method according to claim 4, wherein, in a downlink time slot in which the PDSCH data is first transmitted, the eNB directly sends the PDSCH data and scheduling information in the downlink time slot to Transmitting, by the UE and the relay, the dedicated pilot DRS to the UE, and transmitting, by using the PDCCH or the PDSCH, scheduling information of the PDSCH data on a downlink time slot for retransmitting the PDSCH data to The relay.

The method of claim 4, wherein the method further comprises: receiving, by the eNB, information that the PDSCH data fed back by the UE fails to be demodulated, and after receiving the information, PDSCH data and dedicated pilots are sent to the UE.

The transmitting method according to claim 6, wherein the eNB sends the PDSCH data and its scheduling information in the downlink time slot directly to the downlink time slot in which the PDSCH data is first transmitted. Transmitting, by the UE and the relay, the dedicated pilot DRS to the UE, and transmitting, by using the PDCCH or the PDSCH, scheduling information of the PDSCH data on a downlink time slot for retransmitting the PDSCH data to The eNB transmits the scheduling information of the PDSCH data that is first transmitted in the downlink time slot to the UE through the PDCCH, where the eNB transmits the downlink time slot of the PDSCH data; The retransmitted PDSCH data and the dedicated pilot DRS are sent to the UE.

A data transmission method in a relay system, the method includes: relaying, receiving, by the eNB, PDSCH data and corresponding scheduling information, and according to the The scheduling information, the dedicated pilot DRS and the received PDSCH data are sent to the UE of the relay service; wherein the PDSCH data sent to the UE is subjected to preset beamforming processing, the dedicated pilot The DRS is pilot information corresponding to the beamforming process; the relay does not transmit a common reference signal CRS to the UE.

The transmitting method according to claim 8, wherein the manner in which the relay receives the PDSCH data and the corresponding scheduling information from the eNB is: in a current time slot, the relay receives the PDSCH data and Scheduling information in the downlink time slot;

The manner in which the relay sends the PDSCH data and the dedicated pilot DRS to the UE includes: forwarding, in the next downlink time slot of the current time slot, the PDSCH data received by the current downlink time slot to the Said UE, and transmitting the dedicated pilot to the UE.

10. The transmitting method according to claim 8, wherein:

The manner in which the relay receives the PDSCH data and the corresponding scheduling information from the eNB is: receiving, in the current downlink time slot, the PDSCH data that needs to be sent to the UE in the next downlink time slot, and receiving the PDSCH data that is carried by using the PDCCH. Scheduling information of the downlink time slot; and receiving scheduling information of the N downlink time slots of the PDSCH data sent to itself in the last N downlink time slots in the current frame; and the next N downlinks in the current frame Any downlink time slot n in the slot, receiving PDSCH data that needs to be sent to the UE in the downlink time slot n+1;

The manner in which the relay sends the PDSCH data and the dedicated pilot DRS to the UE includes: any one of the last N downlink slots in the current frame, and the relay will downlink the slot n-1 The received PDSCH data is forwarded to the UE, and the dedicated pilot DRS is transmitted to the UE.

The transmitting method according to claim 8, wherein the relay performs an operation of transmitting PDSCH data and a DRS to the UE after receiving the demodulation failure information fed back by the UE.

An eNB in a relay system, where the eNB includes: a relay interface unit, configured to send, to the relay, PDSCH data to be sent to a UE served by a relay in the system, and send scheduling information corresponding to the PDSCH data to the relay by using a PDCCH; Scheduling information and transmitting a common reference signal CRS to the UE.

The eNB according to claim 12, wherein the relay interface unit is further configured to deliver the PDSCH data and the scheduling information to a plurality of relays serving the UE.

The eNB according to claim 12, wherein the UE interface unit is further configured to, when first transmitting the PDSCH data, the PDSCH data, scheduling information corresponding to the PDSCH data, and dedicated The pilot DRS is sent to the UE.

The eNB according to claim 13, wherein the UE interface unit is further configured to receive, by the UE, information that the PDSCH data is demodulated and failed, and after receiving the information, The PDSCH data, scheduling information corresponding to the PDSCH data, and the DRS are again sent to the UE.

16. A relay in a relay system, the trunk comprising:

The UE interface unit is configured to send the received PDSCH data and the dedicated pilot DRS to the UE that is serving the UE, and does not send the common reference signal CRS to the UE; where the PDSCH data is subjected to preset beamforming processing. The dedicated pilot DRS is pilot information corresponding to the beamforming process.

The relay according to claim 16, wherein the UE interface unit is further configured to receive, by the UE, information that the PDSCH data is demodulated and failed, and after receiving the information, Corresponding to the PDSCH data and the PDSCH data Scheduling information and the DRS are sent to the UE again