Patent Description:
With development of wireless technologies, a device-to-device (D2D for short) communication technology is proposed to relieve network load. User equipments (user equipment, UE for short) within a particular distance range may directly communicate with each other by using the D2D communication technology (D2D technology for short), and a third-party device such as a base station does not need to be used for relaying. As shown in <FIG>, in coverage of a base station, the base station may separately communicate with UE <NUM>, UE <NUM>, and UE <NUM> by using a cellular link. After the D2D technology is used, the UE <NUM> can directly communicate with the UE <NUM> or the UE <NUM> by using a D2D communications link (also referred to as a sidelink SL for short), the UE <NUM> can directly communicate with the UE <NUM> or the UE <NUM> by using the SL, and the UE <NUM> can communicate with the UE <NUM> or the UE <NUM> by using the SL.

In the D2D technology, an idea that user equipment is used as a relay node is proposed to improve a network communication capability. However, how to improve communication reliability of a network using the D2D technology is an urgent problem to be resolved. <CIT> discloses a method, an apparatus, and a computer program product for wireless communication in connection with D2D relay link selection in a LTE based access network. In one example, a communications device is equipped to determine that the communications device (e.g., a UE) is able to establish a relay link with a candidate UE based on at least one of information associated with any preexisting access links with the candidate UE, information associated with any preexisting accessing links within a threshold vicinity of the UE or the candidate UE, or any other UE UL interference, determine that the candidate UE is able to support the relay link based on information associated with preexisting access links for the candidate UE, and perform a link establishment process for the relay link with the candidate UE based on the determinations. <CIT> discloses a method and equipment for transmitting downlink information on a backhaul link. The method includes that: an evolved NodeB (eNB) determines the first area on the backhaul link for transmitting downlink information to a Relay Node (RN) and/or a User Equipment (UE) supporting 3GPP R10(<NUM>), the first area comprising a Relay Physical Downlink Control Channel (R-PDCCH) area and a Relay Physical Hybrid Automatic Repeat request (HARQ) Indicator Channel (R-PHICH) area; the eNB notifies the RN and/or the UE supporting 3GPP R10 of the resource allocation information about the first area(<NUM>); in the first area of the downlink backhaul link, the eNB sends downlink information to the RN and/or the UE supporting 3GPP R10(<NUM>). The invention solves the problem that, in the Long Term Evolution-Advanced (LTE-A) system, no optimized design scheme has been developed for multiplexing the control area and the data area on the backhaul link, and provides the technical solution of semi-static configuration control area for the downlink signals on the backhaul link. <CIT> discloses methods and apparatus related to various considerations for using systems comprising user equipment (UE) relays. One method generally includes receiving, at a UE functioning as a relay, data from a first apparatus; and relaying the received data to a second apparatus, wherein the relaying does not involve interpreting or altering security features of the received data.

Embodiments of the present invention provide a data transmission method, user equipment, and a base station, so as to improve reliability of a network using a D2D technology.

According to the solutions provided in the embodiments of the present invention, uplink transmission and downlink transmission are separately performed in different transmission paths, so as to reduce impact of a fault of the UE-relay on a network, and improve network reliability. In addition, the UE directly receives the downlink data from the base station, and transmits the uplink data by using the UE-realy, and the UE may perform data sending by using relatively small transmit power, so as to reduce power consumption of the UE, and improve an endurance capability of the UE. Further, at a location in proximity of an edge of coverage of the base station, because downlink transmission quality is better than uplink transmission quality, uplink transmission directly performed between the UE and the base station is switched to relaying performed by using the UE-relay, so as to improve uplink transmission quality of the UE. Besides, an uplink transmission distance of the UE may be less than the coverage of the base station due to limitation of maximum transmit power of the UE. Therefore, uplink transmission directly performed between the UE and the base station is switched to relaying performed by using the UE-relay, so as to increase the uplink transmission distance of the UE.

To describe the technical solutions in the embodiments of the present invention or in the prior art more clearly, the following briefly describes the accompanying drawings required for describing the embodiments or the prior art.

The following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are merely some but not all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

A network architecture and a service scenario described in the embodiments of the present invention are intended to describe the technical solutions in the embodiments of the present invention more clearly, but do not constitute a limitation on the technical solutions provided in the embodiments of the present invention. A person of ordinary skill in the art may understand that, with evolution of a network architecture and emergence of a new service scenario, the technical solutions provided in the embodiments of the present invention are also applicable to a similar technical problem.

For ease of understanding, the embodiments of the present invention are described by using a Long Term Evolution (Long Term Evoluation, LTE for short) network defined in the <NUM>rd Generation Partnership Project (<NUM>rd Generation Partnership Project, 3GPP for short) as an example. 3GPP is a project devoted to developing a wireless communications network. Unless otherwise specified in the embodiments, the LTE network in the embodiments of the present invention complies with 3GPP standards. A person skilled in the art may understand that the solutions in the embodiments of the present invention may be applied to another wireless communications network such as a Universal Mobile Telecommunications System ( UMTS for short) network, a <NUM> network, or a subsequent evolved network.

<FIG> shows an example of a communications network using a D2D technology. As shown in <FIG>, UEs (UE <NUM>, UE <NUM>, and UE <NUM>) in coverage of a base station may communicate with the base station, and the UEs may communicate with each other by establishing a D2D link. For example, in <FIG>, when the UE (for example, the UE <NUM>) is on a cell edge, quality of communication between the UE and the base station is relatively poor, but quality of communication between the UE <NUM> or the UE <NUM> and the base station may be better. Therefore, the UE <NUM> or the UE <NUM> may be used as a relay node to relay communication between the UE <NUM> and the base station, so as to ensure quality of the communication between the UE <NUM> and the base station.

For ease of understanding, some terms in this application are described below.

User equipment (UE for short) is a terminal device having a communication function, and may include a handheld device, an in-vehicle device, a wearable device, a computation device, another processing device connected to a wireless modem, or the like that has a wireless communication function. The user equipment may have different names in different networks, for example, a terminal, a mobile station, a subscriber unit, a station, a cellular phone, a personal digital assistant, a wireless modem, a wireless communications device, a handheld device, a laptop computer, a cordless phone, and a wireless local loop station. For ease of description, these devices are abbreviated as user equipment or UE in this application.

User equipment with a relay function may also be referred to as a user equipment relay (UE-relay for short).

<FIG> is a schematic structural diagram of user equipment. For ease of description, <FIG> shows only main components of the user equipment. As shown in <FIG>, user equipment <NUM> includes a processor, a memory, a radio frequency circuit, an antenna, and an input/output apparatus. The processor is mainly configured to: process a communications protocol and communication data, control the entire user equipment, execute a software program, and process data of the software program. The memory is mainly configured to store a software program and data. The radio frequency circuit is mainly configured to: convert a baseband signal and a radio frequency signal, and process the radio frequency signal. The antenna is mainly configured to receive and send a radio frequency signal in an electromagnetic wave form. The input/output apparatus, such as a touchscreen, a screen, or a keyboard, is mainly configured to: receive data entered by a user, and output data to the user. A person skilled in the art may understand that the structure of the user equipment shown in <FIG> is applicable to the UE <NUM>, the UE <NUM>, and the UE <NUM> in <FIG>.

After the user equipment is powered on, the processor may read the software program in the storage unit, explain and execute an instruction of the software program, and process the data of the software program. When the processor needs to send data in a wireless manner, the processor outputs a baseband signal to the radio frequency circuit after performing baseband processing on the to-be-sent data. After performing radio frequency processing on the baseband signal, the radio frequency circuit sends a radio frequency signal in an electromagnetic wave form by using the antenna. When data is sent to the user equipment, the radio frequency circuit receives a radio frequency signal by using the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor. The processor converts the baseband signal into data, and processes the data.

A person skilled in the art may understand that, for ease of description, <FIG> shows only one memory and only one processor. Actually, the user equipment may include multiple processors and multiple memories. The memory may also be referred to as a storage medium, a storage device, or the like. This is not limited in this embodiment of the present invention.

In an optional implementation, the processor may include a baseband processor and a central processing unit. The baseband processor is mainly configured to process a communications protocol and communication data, and the central processing unit is mainly configured to: control the entire user equipment, execute a software program, and process data of the software program. The processor in <FIG> integrates functions of the baseband processor and the central processing unit. A person skilled in the art may understand that the baseband processor and the central processing unit may be separate processors, and are interconnected by using a technology such as a bus. A person skilled in the art may understand that the user equipment may include multiple baseband processors to adapt to different network standards. A person skilled in the art may understand that the user equipment may include multiple central processing units to enhance a processing capability of the user equipment.

A person skilled in the art may understand that the components of the user equipment may be connected by using various buses.

A person skilled in the art may understand that the baseband processor may also be expressed as a baseband processing circuit or a baseband processing chip.

A person skilled in the art may understand that the central processing unit may also be expressed as a central processing circuit or a central processing chip.

A person skilled in the art may understand that a function of processing the communications protocol and the communication data may be embedded in the processor, or may be stored in the storage unit in a form of a software program. The processor executes the software program to implement a baseband processing function.

For example, in this embodiment of the present invention, the antenna and the radio frequency circuit that have receiving and sending functions may be considered as a transceiver unit of the user equipment, and the processor having a processing function may be considered as a processing unit of the user equipment. As shown in <FIG>, the user equipment UE <NUM> includes a transceiver unit <NUM> and a processing unit <NUM>. The transceiver unit may also be referred to as a transceiver, a transceiver machine, a transceiver apparatus, or the like. Optionally, a component that is in the transceiver unit <NUM> and configured to implement a receiving function may be considered as a receiving unit, and a component that is in the transceiver unit <NUM> and configured to implement a sending function may be considered as a sending unit. That is, the transceiver unit <NUM> includes the receiving unit and the sending unit. For example, the receiving unit may also be referred to as a receiver machine, a receiver, or a receiver circuit; the sending unit may be referred to as a transmitter machine, a transmitter, or a transmit circuit.

A base station (BS for short) may also be referred to as a base station device, and is a device deployed in a radio access network to provide a wireless communication function. A base station in an LTE network is referred to as an evolved NodeB (eNB or eNodeB for short).

<FIG> is a schematic structural diagram of a base station. The base station shown in <FIG> may be a distributed base station. For example, on the left of <FIG>, a distributed base station including an antenna (antennas), a remote radio unit (RRU for short), and a baseband unit (BBU for short) is shown. Alternatively, the base station shown in <FIG> may be an integrated base station such as a small cell shown on the right of <FIG>. Generally, the base station includes a part <NUM> and a part <NUM>. The part <NUM> is mainly configured to: receive and send a radio frequency signal, and convert the radio frequency signal and a baseband signal. The part <NUM> is mainly configured to: perform baseband processing, control the base station, and the like. The part <NUM> may be usually referred to as a transceiver unit, a transceiver machine, a transceiver circuit, a transceiver, or the like. The part <NUM> may be usually referred to as a processing unit. Generally, the part <NUM> is a control center of the base station.

As shown in <FIG>, in an optional implementation, the part <NUM> may include an antenna and a radio frequency unit. The radio frequency unit is mainly configured to perform radio frequency processing. Optionally, a component that is in the part <NUM> and configured to implement a receiving function may be considered as a receiving unit, and a component that is in the part <NUM> and configured to implement a sending function may be considered as a sending unit. That is, the part <NUM> includes the receiving unit and the sending unit. For example, the receiving unit may also be referred to as a receiver machine, a receiver, or a receiver circuit; the sending unit may be referred to as a transmitter machine, a transmitter, or a transmit circuit.

As shown in <FIG>, in an optional implementation, the part <NUM> may include one or more boards. Each board may include a processor and a memory, and the processor is configured to read and execute a program in the memory to implement a baseband processing function and control the base station. If there are multiple boards, the boards may be interconnected to enhance a processing capability.

In another optional implementation, with development of a system-on-chip (SoC for short) technology, functions of the part <NUM> and the part <NUM> may be implemented by using the SoC technology, that is, the functions of the part <NUM> and the part <NUM> may be implemented by using a functional chip of the base station. The functional chip of the base station integrates components such as the processor, the memory, and the antenna. A program having related functions of the base station is stored in the memory, and the processor executes the program to implement the related functions of the base station.

In the network shown in <FIG>, by using the D2D technology, the UE <NUM> may communicate with the base station by using the UE <NUM>, that is, the UE <NUM> may exchange both uplink data and downlink data with the base station by using the UE <NUM>. Because quality of a signal between the UE <NUM> and the base station or between the UE <NUM> and the UE <NUM> may be poorer due to movement of the UE <NUM>, or a case such as power off or a fault may occur in a relay process, network reliability may decrease when a relay function is implemented by using the user equipment.

An embodiment of the present invention provides a data transmission method. As shown in <FIG>, in S401, UE sends uplink data to a base station by using a UE-relay. When the UE-relay is used to relay the uplink data, the UE-relay may also be referred to as an uplink UE-relay or an uplink UE-relay. That is, a transmission path of the uplink data of the UE is UE→(uplink UE-relay)→BS. In an optional implementation of S401, a sending unit of the UE may be configured to send the uplink data to the base station by using the UE-relay, and a transceiver unit of the base station (or a receiving unit in a transceiver unit of the base station) may be configured to receive the uplink data of the UE by using the UE-relay.

In S402, the UE receives downlink data sent by the base station. In an optional implementation of S402, a receiving unit of the UE may be configured to receive the downlink data sent by the base station, and the transceiver unit of the base station (or a sending unit in the transceiver unit of the base station) may be configured to send the downlink data to the UE.

Specifically, in an example, the UE may receive, from the base station, the downlink data sent by the base station. That is, a transmission path of the downlink data is BS→UE, and a transmission path of the uplink data is UE→(uplink UE-relay)-BS. When this example is applied to the network shown in <FIG>, assuming that the UE <NUM> is used as the UE in <FIG>, the uplink UE-relay may be any UE having a relay function in the network, for example, the UE <NUM> or the UE <NUM>. In this example, the transmission path of the uplink data between the UE and the base station is different from the transmission path of the downlink data between the UE and the base station. The UE-relay is used only on a link of the uplink data, so as to reduce impact of the UE-relay on network reliability, and improve reliability of a network using a D2D technology.

In another example, the UE may also receive, by using the UE-relay, the downlink data sent by the base station. When the UE-relay is used to relay the downlink data, the UE-relay may also be referred to as a downlink UE-relay or a downlink UE-relay. That is, in this example, a transmission path of the uplink data is UE→(uplink UE-relay)-BS, and a transmission path of the downlink data is BS→(downlink UE-relay)-UE. In an optional implementation, the receiving unit of the UE may be configured to receive, by using the UE-relay, the downlink data sent by the base station, and the transceiver unit of the base station (or the sending unit in the transceiver unit of the base station) may be configured to send the downlink data to the downlink UE-relay. In addition, in this example, because uplink transmission and downlink transmission of the UE are respectively performed by using the uplink UE-relay and the downlink UE-relay, when the UE leaves coverage of the base station, the UE may still perform uplink transmission and downlink transmission with the base station by using the uplink UE-relay and the downlink UE-relay. That is, a distance of communication between the UE and the base station increases.

The downlink UE-relay and the uplink UE-relay are acted by different user equipments. For example, when this example is applied to the network shown in <FIG>, assuming that the UE <NUM> is used as the UE and the downlink UE-relay is the UE <NUM>, the uplink UE-relay is another UE other than the UE <NUM>, for example, the UE <NUM>. In this example, in uplink transmission and downlink transmission, different UE-relays are separately used as the uplink UE-relay and the downlink UE-relay, so as to avoid impact exerted by movement of a single UE-relay or a communication fault on communication between the UE and the base station, and improve reliability of a network using a D2D technology.

Preferably, quality of communication between the downlink UE-relay and the base station is better than quality of communication between the UE and the base station. For example, quality of service (Quality of Service, QoS) is better. In this way, quality of downlink transmission of the UE can be improved. Certainly, the present invention is not limited thereto.

Preferably, a distance between the UE and the uplink UE-relay may be shorter than a distance between the UE and the base station. In this case, when another factor affecting signal quality is not considered, transmit power required for sending the uplink data to the uplink UE-relay by the UE is less than transmit power required for sending the uplink data to the base station by the UE, so as to help reduce power consumption of the UE, and implement power saving. Optionally, after receiving the uplink data sent by the UE, the uplink UE-relay may send a downlink reply of the uplink UE-relay to the uplink data, such as an ACK/NACK, to the UE. In an optional implementation, the receiving unit of the UE may be configured to receive the downlink reply. A person skilled in the art may understand that a reply may also be expressed as a response.

Optionally, after receiving the downlink data forwarded by the downlink UE-relay, the UE may send a reply to the downlink data, such as an ACK/NACK, to the downlink UE-relay. For example, the sending unit of the UE may be configured to send the reply to the downlink UE-relay.

Optionally, communication between the UE and the user equipment relay (for example, the uplink UE-relay or the downlink UE-relay) may be performed in a unicast or broadcast manner.

After the UE receives the downlink data sent by the base station, the UE needs to send the reply to the downlink data to the base station on a PUCCH resource allocated by the base station to the UE, so that the base station can learn that the reply is sent by the UE for the downlink data. A person skilled in the art should understand that the reply may be understood as one type of the uplink data sent by the UE to the base station.

The UE may send first indication information to the uplink UE-relay. The first indication information is used to indicate a PUCCH resource corresponding to the UE. In an optional implementation, the sending unit of the UE may be configured to send the first indication information. A person skilled in the art may understand that the PUCCH resource corresponding to the UE may be expressed as a PUCCH resource allocated to the UE, or a PUCCH resource configured for the UE. After receiving the PUCCH resource, the uplink UE-relay sends a reply of the UE to the base station by using the PUCCH resource. After the base station receives the reply on the PUCCH resource, the base station considers that the reply is sent by the UE for the downlink data.

The first indication information includes may include nCCE and <MAT>, where nCCE is used to indicate a number of a first control channel element (CCE for short) that is in a physical downlink control channel (PDCCH for short) and that is used to indicate downlink transmission, and <MAT> is used to indicate a UE-dedicated PUCCH ACK/NACK offset or used to indicate a PUCCH format 1a/1b start offset used for a subframe set K2.

In an optional implementation, the first indication information may include nCCE,q, ΔARO and <MAT>, where nECCE,q is used to indicate a number of a first ECCE (enhanced control channel element) that is in an EPDCCH-PRB-set q (a PRB set q corresponding to an EPDCCH, where the EPDCCH is an enhanced PDCCH and expressed as an enhanced physical downlink control channel) and that is used to transmit corresponding DCI (downlink control information), ΔARO is used to indicate a value of a HARQ-ACK resource offset field in DCI format (for a specific value of ΔARO , refer to Table <NUM>), and <MAT> is used to indicate a PUCCH resource start offset corresponding to the EPDCCH-PRB-set q.

In an optional implementation, the first indication information may include nECCE,q, ΔARO, <MAT>, and n'. For nECCE,q, ΔARO , and <MAT>, refer to the foregoing content. n' is used to indicate a value of an antenna port used for centralized EPDCCH transmission (for a specific value of n' , refer to Table <NUM>).

For example, for specific meanings and use manners of these parameters: nCCE, <MAT>, nECCE,q, ΔARO, <MAT>, and n' that are included in the first indication information, refer to content in the chapter <NUM>. <NUM> in the 3GPP standard: 3GPP TS <NUM> v12.

A person skilled in the art may understand that the parameters: nCCE, <MAT>, nECCE,q, ΔARO <MAT>, and n' that are included in the first indication information may be applied to an LTE FDD (frequency division duplex) network.

A person skilled in the art may understand that the following parameters included in the first indication information may be applied to an LTE TDD (time division duplex) network.

In an optional implementation, the first indication information may include M, m, nCCE, and <MAT>.

In an optional implementation, the first indication information may include nECCE,q, <MAT>, m, NECCE,q,n-ki<NUM>, and ΔARO.

In an optional implementation, the first indication information may include nECCE,q, <MAT>, m, n', ΔARO, and NECCE,q,n-ki<NUM>.

For example, for specific meanings and use manners of the parameters: M, m, nCCE, <MAT>, nECCE,q <MAT>, m, n', ΔARO, and NECCE,q,n-ki1 that are included in the first indication information and may be applied to the LTE TDD network, refer to content in the chapter <NUM>. <NUM> in the 3GPP standard: 3GPP TS <NUM> v12.

Optionally, if the UE needs to send a periodic channel quality indicator (channel quality indication, CQI for short) to the base station when sending the reply to the base station, the first indication information may further include <MAT>. <MAT> is used to indicate an index of a CQI allocated to the UE. The uplink UE-relay may send, to the base station by using the first indication information, both the reply of the UE to the uplink data and the CQI fed back by the UE.

Preferably, to enable the base station to correctly receive the reply (or the reply and the periodic CQI) that is to the downlink data and forwarded by the uplink UE-relay on the PUCCH resource, the base station may receive the reply (or the reply and the periodic CQI) on the PUCCH resource after a delay of m transmission time intervals (transmission time interval, TTI for short). A person skilled in the art may understand that the reply (or the reply and the periodic CQI) herein may be understood as one type of the uplink data sent by the UE to the base station.

In an optional implementation, the transceiver unit of the base station (or the receiving unit in the transceiver unit of the base station) may be configured to receive the uplink data on the PUCCH resource. Further, the transceiver unit of the base station may receive the uplink data on the PUCCH resource after the delay of m TTIs.

Preferably, the m TTIs are greater than or equal to a time required when the user equipment sends the second indication information and the reply to the downlink data to the uplink UE-relay. In this way, a HARQ procedure is less affected.

After the uplink UE-relay forwards the uplink data of the UE to the base station, the base station sends a reply to the uplink data. Because the uplink data is sent by the uplink UE-relay to the base station, the base station sends the reply on a physical hybrid automatic repeat request indicator channel (PHICH for short) resource corresponding to the uplink UE-relay, so that the uplink UE-relay can receive the reply. A person skilled in the art may understand that the PHICH resource corresponding to the uplink UE-relay may be expressed as a PHICH resource allocated to the uplink UE-relay, or a PHICH resource configured for the uplink UE-relay.

Preferably, to enable the UE to directly receive the reply of the base station to the uplink data from the base station, the uplink UE-relay may notify the UE of the PHICH resource corresponding to the uplink UE-relay. The UE may receive the reply to the uplink data from the base station according to the PHICH resource. For example, the receiving unit of the UE may be configured to receive second indication information from the uplink UE-relay. The second indication information is used to indicate the PHICH resource corresponding to the uplink UE-relay. The second indication information may include nDMRS and <MAT>, where nDMRS is used to indicate a DMRS offset, and <MAT> is used to indicate a minimum index of a PRB for uplink transmission. A person skilled in the art should understand that, because the UE directly receives the reply from the base station, the reply may be understood as one type of the downlink data sent by the base station to the UE.

With reference to the network shown in <FIG>, the method shown in <FIG> is further described in a scenario A and a scenario B below.

In the scenario A, the uplink UE-relay is the UE <NUM>, the user equipment UE <NUM> sends uplink data to the base station by using the UE <NUM>, and the UE <NUM> directly receives downlink data from the base station.

As shown in <FIG>:
S501. The UE <NUM> sends uplink data to the UE <NUM>.

The UE <NUM> may send the uplink data to the UE <NUM> in a unicast or broadcast manner.

Optionally, in S502, the UE <NUM> sends a reply to the uplink data to the UE <NUM>.

For example, the reply may be an ACK or a NACK. When the UE <NUM> receives the NACK, the UE <NUM> may resend the uplink data to the UE <NUM>.

The UE <NUM> sends the uplink data to the base station.

For example, the UE <NUM> may send the uplink data to the base station by using a physical uplink shared channel (PUSCH for short) resource configured by the base station for the UE <NUM>.

For example, the PUSCH resource may be obtained by the UE <NUM> by using a scheduling request (SR for short). The base station sends a reply to the uplink data.

For example, the base station sends the reply according to a PHICH resource allocated to the UE <NUM>.

The reply sent by the base station on the PHICH resource may be received by the UE <NUM> (refer to S5051), or may be received by the UE <NUM> (refer to S504 and S5052).

Optionally, in S5051, the UE <NUM> receives the reply of the base station to the uplink data on a PHICH resource allocated by the base station to the UE <NUM>.

Optionally, in S504, the UE <NUM> sends second indication information to the UE <NUM>, where the second indication information is used to indicate the PHICH resource. In this way, the UE <NUM> may receive the reply of the base station to the uplink data on the PHICH resource. For the second indication information, refer to the second indication information in <FIG>.

Optionally, in S5052, the UE <NUM> receives the reply of the base station to the uplink data on the PHICH resource allocated by the base station to the UE <NUM>.

S501 to S505 provide a specific implementation of S402 as an example.

S506 to S510 provide a specific implementation of S401 as an example.

The base station sends downlink data to the UE <NUM>.

For example, the base station sends the downlink data to the UE <NUM> by using a physical downlink shared channel (PDSCH for short) resource.

The UE <NUM> sends first indication information to the UE <NUM>.

The first indication information is used to indicate a PUCCH resource corresponding to the UE <NUM>, that is, a PUCCH resource configured for the UE <NUM>. For the first indication information, refer to the first indication information in <FIG>.

The UE <NUM> sends a reply to the downlink data to the UE <NUM>.

Optionally, the UE <NUM> may further send a periodic CQI to the UE <NUM>.

A sequence between S507 and S508 is not limited. The UE <NUM> may send the second indication information, the reply to the downlink data, or the periodic CQI to the UE <NUM> in a broadcast or unicast manner.

Optionally, in S509, the UE <NUM> sends a reply to the first indication information, a reply to the downlink data, or a reply to the periodic CQI to the UE <NUM>.

The UE <NUM> sends the reply of the UE <NUM> to the downlink data to the base station.

For example, the UE <NUM> sends the reply of the UE <NUM> to the downlink data to the base station according to the PUCCH resource configured for the UE <NUM>.

It can be learned, from the description of the method shown in <FIG>, that uplink data and downlink data are transmitted in different transmission paths, so as to reduce impact of a user equipment relay on transmission reliability. When a fault occurs in an uplink, the base station may further contact the user equipment in a downlink, so as to perform subsequent remedies, and improve network reliability.

In the scenario B, the downlink UE-relay is the UE <NUM>, and the uplink UE-realy is the UE <NUM>. The UE <NUM> sends uplink data to the base station by using the UE <NUM>, and receives downlink data from the base station by using the UE <NUM>. The UE <NUM> may be in coverage of the base station or may be outside coverage of the base station.

As shown in <FIG>:
S601. The UE <NUM> sends uplink data by using the UE <NUM>.

For example, for an example in which the UE <NUM> sends the uplink data by using the UE <NUM>, refer to S501 to S505.

For example, S602 to S605 provide one of specific implementations of S401 as an example.

The base station sends downlink data to the UE <NUM>.

For example, the base station sends the downlink data to the UE <NUM> by using a PDSCH resource in S602.

The UE <NUM> sends a reply of the UE <NUM> to the downlink data to the base station.

For example, the UE <NUM> may send the reply to the downlink data to the base station according to a PUCCH resource configured for the UE <NUM>.

The UE <NUM> sends the downlink data to the UE <NUM>.

For example, the UE <NUM> may send the downlink data to the UE <NUM> in a broadcast or unicast manner.

Optionally, in S605, the UE <NUM> sends a reply of the UE <NUM> to the downlink data to the UE <NUM>.

In this embodiment of the present invention, different user equipment relays separately forward the uplink data and the downlink data of the user equipment, so as to reduce impact of a fault of a single user equipment relay on a network, and improve network reliability.

A person skilled in the art may understand that an embodiment of the present invention further provides user equipment. For a structure of the user equipment, refer to <FIG>. For a mechanism used by the user equipment to implement an objective of this embodiment of the present invention, refer to the UE <NUM> in the foregoing embodiments.

A person skilled in the art may understand that an embodiment of the present invention further provides user equipment, and the user equipment is used as a user equipment relay. For a structure of the user equipment, refer to <FIG>. For a mechanism used by the user equipment to implement an objective of this embodiment of the present invention, refer to the UE <NUM> in the foregoing embodiments.

A person skilled in the art may understand that an embodiment of the present invention further provides a base station. For a structure of the base station, refer to <FIG>. For a mechanism used by the base station to implement an objective of this embodiment of the present invention, refer to the base station in the foregoing embodiments.

A person skilled in the art may understand that an embodiment of the present invention further provides a data transmission system, so as to implement an objective of this embodiment of the present invention. The system may include UE <NUM> and UE <NUM>, and may further include a base station or UE <NUM>. For a mechanism used by the system to implement the method provided in the embodiments of the present invention, refer to the foregoing embodiments.

A person skilled in the art may further understand that various illustrative logical blocks (illustrative logic block) and steps (step) that are listed in the embodiments of the present invention may be implemented by using electronic hardware, computer software, or a combination thereof. Whether the functions are implemented by using hardware or software depends on particular applications and a design requirement of the entire system. A person skilled in the art may use various methods to implement the described functions for each particular application, but it should not be understood that the implementation goes beyond the protection scope of the embodiments of present invention.

The various illustrative logical units and circuits described in the embodiments of the present invention may implement or operate the described functions by using a general purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or another programmable logic apparatus, a discrete gate or transistor logic, a discrete hardware component, or a design of any combination thereof. The general purpose processor may be a microprocessor. Optionally, the general purpose processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented by a combination of computing apparatuses such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors with a digital signal processor core, or any other similar configuration.

Steps of the methods or algorithms described in the embodiments of the present invention may be directly embedded into hardware, a software unit executed by a processor, or a combination thereof. The software unit may be stored in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable magnetic disk, a CD-ROM, or a storage medium of any other form in the art. For example, the storage medium may connect to a processor, so that the processor may read information from the storage medium and write information to the storage medium. Alternatively, the storage medium may be integrated into the processor. The processor and the storage medium may be arranged in an ASIC, and the ASIC may be arranged in UE. Optionally, the processor and the storage medium may be arranged in different components of the UE.

For example, in one or more designs, the functions described in the embodiments of the present invention may be implemented by using hardware, software, firmware, or any combination thereof. If being implemented by using the software, these functions may be stored in a computer-readable medium or are transmitted to the computer-readable medium in a form of one or more instructions or code. The computer-readable medium includes a computer storage medium and a communications medium that enables a computer program to move from one location to another. The storage medium may be an available medium that may be accessed by any general or special computer. For example, such a computer-readable medium may include but is not limited to a RAM, a ROM, an EEPROM, a CD-ROM or another optical disc storage, a disk storage or another magnetic storage apparatus, or any other media that may be used to carry or store program code that is in a form of an instruction or a data structure or in a form that can be read by a general or special computer or by a general or special processor. In addition, any connection may be appropriately defined as a computer-readable medium. For example, if software is transmitted from a website, a server, or another remote resource by using a coaxial cable, an optical fiber computer, a twisted pair, or a digital subscriber line (DSL) and in a wireless manner such as infrared, radio, or microwave, the software is included in a defined computer-readable medium. The disc (disk) and the disk (disc) include a compressed disk, a laser disk, an optical disc, a DVD, a floppy disk, and a Blu-ray disc. The disk generally copies data in a magnetic manner, and the disc generally copies data optically in a laser manner. The foregoing combination may also be included in the computer-readable medium.

Claim 1:
A data transmission method, comprising:
sending (S401), by user equipment, UE, uplink data to a base station by using an uplink user equipment relay uplink, UE-relay;
receiving (S402), by the UE, downlink data from the base station; characterized by
sending, by the UE, first indication information to the uplink UE-relay, wherein the first indication information is used to indicate an uplink transmission resource corresponding to the UE, so that the uplink UE-relay sends the uplink data to the base station according to the uplink transmission resource; and
receiving, by the UE, second indication information from the uplink UE-relay, wherein the second indication information is used to indicate a downlink transmission resource corresponding to the uplink UE-relay, wherein
the uplink transmission resource comprises a physical uplink control channel PUCCH resource; and
the first indication information comprises nCCE and <MAT>, wherein nCCE is used to indicate a number of a first control channel element CCE that is in a physical downlink control channel PDCCH and that is used to indicate downlink transmission, and <MAT> is used to indicate a UE-dedicated PUCCH ACK/NACK resource offset or used to indicate a PUCCH format 1a/1b start offset used for a subframe set K2.