Patent Description:
Device-to-device (Device to Device, D2D) communication, vehicle-to-vehicle (Vehicle to Vehicle, V2V) communication, vehicle-to-pedestrian V2P (Vehicle to Pedestrian, V2P) communication, or vehicle-to-infrastructure/network V2I/N (Vehicle to Infrastructure/Network, V2I/N) communication is a technology for direct communication between terminal devices (terminal device). V2V, V2P, and V2I/N are collectively referred to as V2X, namely, communication between vehicles and anything.

Using the V2X communication as an example, the V2X communication includes a mode <NUM> (Mode <NUM>) and a mode <NUM> (Mode <NUM>). In the mode <NUM>, a terminal device performs control information and data communication with another terminal device on a time-frequency resource allocated by an access network device. In the mode <NUM>, a terminal device autonomously selects a time-frequency resource and performs control information and data communication with another terminal device on the selected time-frequency resource. In conventional V2X communication, after receiving data, a receive-end terminal device does not feed back, to notify the transmit-end terminal device whether the receive-end terminal device correctly receives the data, response information to a transmit-end terminal device that sends the data.

<CIT> discloses a resource pool configuration method. The method comprises: configuring a physical sidelink second control channel (PSSCCH) resource pool, herein resources in the PSSCCH resource pool are used by user equipment (UE) which performs device-to-device (D2D) communication to carry and send feedback control information of physical sidelink.

<CIT> describes that HARQ feedback is enabled for unicast sidelink communications to improve the spectral efficiency and enable better radio resource utilization for the network.

<NPL>, discusses the association of resource allocation and pool design with different V2X message types and priorities in the context of autonomous mode.

The invention is defined in independent claims <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM>. Embodiments and examples not covered by the claims are meant to illustrate, and facilitate the understanding of, the claimed invention.

In <FIG>, a network device sends indication information to a first communications device and a second communications device. The indication information indicates a resource configured by the network device for transmitting response information between the first communications device and the second communications device. The first communications device may determine, through scheduling by a base station or autonomous selection, a resource used to send data, and send, on the resource, the data to the second communications device. The second communications device may correctly receive the data, or cannot correctly receive the data. Then, the second communications device sends, on the resource for transmitting the response information that is indicated by the indication information, the response information to the first communications device, and the response information is used to feed back a transmission status of the data. The response information may be acknowledgement (acknowledgement, ACK) information or negative acknowledgement (negative acknowledgement, NACK) information.

The network device in this application is an apparatus that is deployed in a radio access network and that is configured to provide a wireless communication function for a communications device. The network device may include various forms of base stations (Base Station, BS), such as a macro base station, a micro base station, a relay node, or an access point. In systems using different radio access technologies, a device having a network device function may have different names. For example, in a 5th generation <NUM> network, the device is a network device; in an LTE network, the device is referred to as an evolved NodeB (evolved NodeB, eNB or eNodeB for short); and in a 3rd generation <NUM> network, the device is referred to as a NodeB (NodeB). The device is alternatively a road side unit (Road Side Unit, RSU) in V2V communication, or the network device may be a chip or a system on chip (System on Chip, SOC). For ease of description, in this application, the foregoing apparatus that provides the wireless communication function for the communications device is collectively referred to as the network device.

The communications device in this application may include various handheld devices having the wireless communication function, for example, a vehicle-mounted device, a wearable device, a computing device, or another processing device connected to a wireless modem, a mobile station (Mobile station, MS), a terminal (terminal), user equipment (User Equipment, UE), a chip, or an SOC. For ease of description, in this application, the devices mentioned above are collectively referred to as the communications device.

The following describes the embodiments of this application in more detail with reference to specific examples by using a network device, a first communications device, and a second communications device as an example.

<FIG> shows a response information transmission method, a first communications device, a second communications device, a network device, and a system according to an embodiment of this application. As shown in <FIG>, the first communications device includes a receiving unit <NUM> and a sending unit <NUM>. The first communications device may further include a determining unit <NUM>, and the receiving unit <NUM> and the sending unit <NUM> communicate with the determining unit <NUM>. As shown in <FIG>, the second communications device includes a receiving unit <NUM> and a sending unit <NUM>. The second communications device may further include a determining unit <NUM>, and the receiving unit <NUM> and the sending unit <NUM> communicate with the determining unit <NUM>. As shown in <FIG>, the network device includes a sending unit <NUM>. The network device may further include a determining unit <NUM> and a receiving unit <NUM>, and the receiving unit <NUM> and the sending unit <NUM> communicate with the determining unit <NUM>.

Step <NUM>: The sending unit <NUM> of the network device sends first indication information to at least one communications device. Specifically, as shown in <FIG>, the network device sends first indication information to the first communications device and the second communications device. The receiving unit <NUM> of the first communications device receives the first indication information from the network device, and the receiving unit <NUM> of the second communications device also receives the first indication information from the network device, where the first indication information is used to indicate a first resource for transmitting first data. The network device notifies, by using the first indication information, the first communications device and the second communications device of the resource allocated by the network device for V2X communication between the first communications device and the second communications device, so that the first communications device and the second communications device can perform data transmission on the resource allocated by the network device.

In <FIG>, a sequence in which the network device sends the first indication information to the first communications device and sends the first indication information to the second communications device is not limited. Preferably, the network device sends, in a broadcast manner, the first indication information to the first communications device and the second communications device, where the first indication information may be bit map information, and the first indication information may be sent by using radio resource control (Radio Resource Control, RRC) signaling. Specifically, as shown in <FIG>, the first indication information is used by the network device to indicate, to a plurality of communications devices, time domain information of the resource allocated by the network device for the V2X communication. A length of a bit map shown in <FIG> is <NUM> bits, and the bit map is specifically <NUM>. The bit map is used to periodically indicate time domain resources used for V2X communication. For example, the bit map is used to indicate that a subframe <NUM>, a subframe <NUM>, and a subframe <NUM> can be used as resources that can be used for V2X communication in the first period, and in the second period, the bit map indicates that a subframe <NUM>, a subframe <NUM>, and a subframe <NUM> may be used as resources that can be used for V2X communication in the second period. In other words, the first resource indicated by the first indication information includes subframes that can be used for V2X communication.

In <FIG>, for a subframe used for V2X communication, the network device divides a frequency domain resource into several sub-channels, and each sub-channel includes several resource blocks (Resource Block, RB). The network device indicates, to the communications device by using the indication information, a sequence number of the first resource block of a resource used for V2X communication. A quantity of resource blocks included in each sub-channel is nCH, and a quantity of sub-channels that can be used for V2X communication is N, where nCH and N are positive integers. Preferably, the network device may notify, by using the first indication information, the first communications device and the second communications device of the sequence number of the first resource block of the resource used for the V2X communication resource, nCH, and N. Certainly, the network device may alternatively send the foregoing information to the first communications device and the second communications device by using other indication information.

Step <NUM>: The sending unit <NUM> of the first communications device sends, on the first resource indicated by the first indication information, the first data to the second communications device, and the receiving unit <NUM> of the second communications device receives, on the first resource, the first data from the first communications device. The first data may be status information periodically sent by a vehicle to another vehicle, such as location information, speed information, or other status information. The second communications device may learn of status information of the first communications device, and adjust a traveling direction, a speed, and the like of the second communications device based on the status information of the first communications device, and therefore, travelling safety of the second communications device is improved. Preferably, the first communications device sends, in a broadcast manner, the first data to the second communications device and another communications device around the first communications device.

Although the first communications device sends the first data to the second communications device, the second communications device may correctly receive the first data, or may not correctly receive the first data.

Step <NUM>: The sending unit <NUM> of the network device sends second indication information to the at least one communications device. Specifically, as shown in <FIG>, the network device sends second indication information to the first communications device and the second communications device. The receiving unit <NUM> of the first communications device receives the second indication information from the network device, the receiving unit <NUM> of the second communications device also receives the second indication information from the network device, where the second indication information is used to indicate a second resource for transmitting response information of the first data, and the second resource and the first resource do not include a same resource.

The second indication information may include bit map information. A bit map is used to periodically indicate a resource used for response information transmission. As shown in <FIG>, a first bit map is <NUM>, and indicates that subframes used for V2X data transmission are a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, and the like, and that a subframe <NUM> to a subframe <NUM> and a subframe <NUM> to a subframe <NUM> are common subframes. A second bit map is <NUM>, and indicates that subframes used for transmitting the response information of the data are a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, and the like. Resources used for response information transmission and resources used for V2X data transmission do not include a same resource, in other words, the resources used for response information transmission and the resources used for V2X data transmission are different resources. Preferably, response information of V2X data is transmitted in the first subframe that appears after a resource used for transmitting the V2X data. For example, as shown in <FIG>, response information of V2X data transmitted in the subframe <NUM> and the subframe <NUM> is fed back in the subframe <NUM>. Response information of V2X data transmitted in the subframe <NUM> and the subframe <NUM> is fed back in the subframe <NUM>. The response information includes ACK information or NACK information, and the response information does not include additional information. For example, the response information does not include communications device identification information corresponding to the response information, or does not include data packet identification information corresponding to the response information. Therefore, a specific rule needs to be preset in a communications protocol, so that the communications device learns of a specific data packet of a specific communications device to which the response information belongs. For example, the preset rule may be in ascending order of subframe numbers and in ascending order of sub-channel numbers. Sub-channels in a subframe with a smaller subframe number are first mapped to the response information transmission resource, and then sub-channels in a subframe with a larger subframe number are mapped to the response information transmission resource. For example, in <FIG>, the subframe <NUM> includes four sub-channels: a sub-channel <NUM> to a sub-channel <NUM>, and the subframe <NUM> also includes four sub-channels: a sub-channel <NUM> to a sub-channel <NUM>. In this case, an ACK/NACK resource <NUM> is used to feed back response information of the sub-channel <NUM> in the subframe <NUM>, an ACK/NACK resource <NUM> is used to feed back response information of the sub-channel <NUM> in the subframe <NUM>, an ACK/NACK resource <NUM> is used to feed back response information of the sub-channel <NUM> in the subframe <NUM>, an ACK/NACK resource <NUM> is used to feed back response information of the sub-channel <NUM> in the subframe <NUM>, an ACK/NACK resource <NUM> is used to feed back response information of the sub-channel <NUM> of the sub-frame <NUM>, an ACK/NACK resource <NUM> is used to feed back response information of the sub-channel <NUM> of the sub-frame <NUM>, an ACK/NACK resource <NUM> is used to feed back response information of the sub-channel <NUM> of the sub-frame <NUM>, and an ACK/NACK resource <NUM> is used to feed back response information of the sub-channel <NUM> in the subframe <NUM>. Preferably, a location of the resource used to transmit the ACK/NACK may be a function of an index of a slot in which data corresponding to the ACK/NACK is located and a lowest sub-channel index.

The first resource includes x subframes, where x is a positive integer, and the sending, by the first communications device on the first resource, the first data to the second communications device includes: sending, by the first communications device in a subframe n, the first data to the second communications device, where the subframe n belongs to the x subframes. The second resource includes y subframes, where y is a positive integer, and the receiving, by the first communications device on the second resource, the response information of the first data from the second communications device includes: receiving, by the first communications device in a subframe m, the response information of the first data from the second communications device, where the subframe m belongs to the y subframes, and the subframe m is a subframe, after a subframe n+k, with a smallest sequence number in the y subframes of the second resource, where the subframe n+k is a kth subframe after the subframe n, and n, m, and k are all non-negative integers. If the subframe n+k is a subframe that belongs to the second resource, a resource used to feed back response information of data transmitted in the subframe n may be the subframe n+k, or may be a subframe n+k+<NUM>.

A value of k may be predefined in a protocol. For example, as shown in <FIG>, a first resource includes a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, and the like, a second resource includes a subframe <NUM>, a subframe <NUM>, and the like, and that a value of k is <NUM> is preset in the protocol. For the subframe <NUM>, a value of n is <NUM>, so that a value of n+k is <NUM>. In this case, a subframe, after a subframe <NUM>, with a smallest sequence number in the second resource is the subframe <NUM>, so that response information of data transmitted in the subframe <NUM> is fed back in the subframe <NUM>. Similarly, response information of data transmitted in the subframe <NUM> is fed back in the subframe <NUM>, response information of data transmitted in the subframe <NUM> is fed back in the subframe <NUM>, and the rest may be deduced by analogy.

A value of k may alternatively be semi-statically configured or dynamically configured. For example, the value of k may be sent by the network device to the first communications device or the second communications device, or the value of k may be sent by the network device to the first communications device and then sent by the first communications device to the second communications device. The value of k may be independently configured for different subframes, may be configured for a subframe in a period, or may be configured to be the same for all subframes. As shown in <FIG>, a first resource includes a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, and the like, a second resource includes a subframe <NUM>, a subframe <NUM>, and the like. Therefore, for the subframe <NUM>, a value of n is <NUM>, so that a value of n+k is <NUM>. Therefore, a subframe, after a subframe <NUM>, with a smallest sequence number in the second resource is the subframe <NUM>, so that response information of data transmitted in the subframe <NUM> is fed back in the subframe <NUM>. For the subframe <NUM>, a value of n is <NUM>, a value of k is <NUM>, so that a value of n+k is <NUM>. Therefore, a subframe, after the subframe <NUM>, with a smallest sequence number in the second resource is the subframe <NUM>, so that response information of data transmitted in the subframe <NUM> is fed back in the subframe <NUM>. For the subframe <NUM>, a value of n is <NUM>, a value of k is <NUM>, so that a value of n+k is <NUM>. Therefore, a subframe, after the subframe <NUM>, with a smallest sequence number in the second resource is the subframe <NUM>, so that response information of data transmitted in the subframe <NUM> is fed back in the subframe <NUM>. The rest may be deduced by analogy.

Optionally, the subframe m includes a plurality of first time units, and the receiving, by the first communications device in the subframe m, the response information of the first data from the second communications device includes: receiving, by the first communications device on one of the plurality of first time units included in the subframe m, the response information of the first data from the second communications device. Preferably, the first time unit may be a slot, a mini-slot, or a symbol. Specifically, a specific first time unit or several specific first time units that are in the plurality of first time units included in the subframe m and that are used for response information transmission may be predefined by a protocol, or may be semi-statically or dynamically configured by the network device. For example, as shown in <FIG>, a first bit map is <NUM>, and therefore, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, and the like are a first resource used for V2X data transmission. A second bit map is <NUM>, and therefore, a subframe <NUM>, a subframe <NUM>, and the like are a second resource used for response information transmission. It can be learned that the subframe <NUM>, the subframe <NUM>, and the like are used for both V2X data transmission and response information transmission. A mini-slot <NUM> in the subframe <NUM> is used for data transmission, and a mini-slot <NUM> in the subframe <NUM> is used for response information transmission. If response information of data transmitted in the subframe <NUM>, the subframe <NUM>, and the mini-slot <NUM> in the subframe <NUM> is fed back in the mini-slot <NUM> in the subframe <NUM>, and when the subframe <NUM> and the subframe <NUM> each include two sub-channels and the mini-slot <NUM> in the subframe <NUM> includes only one sub-channel, a response information resource <NUM> is used to feed back response information of data transmitted on a sub-channel <NUM> in the subframe <NUM>, a response information resource <NUM> is used to feed back response information of data transmitted on a sub-channel <NUM> in the subframe <NUM>, a response information resource <NUM> is used to feed back response information of data transmitted on a sub-channel <NUM> in the subframe <NUM>, a response information resource <NUM> is used to feed back response information of data transmitted on a sub-channel <NUM> in the subframe <NUM>, and a response information resource <NUM> is used to feed back response information of data transmitted on a sub-channel <NUM> in the mini-slot <NUM> in the subframe <NUM>. Therefore, resource utilization efficiency can be improved.

Optionally, the receiving, by the first communications device in the subframe m, the response information of the first data from the second communications device includes: receiving, by the first communications device on some frequency domain resources in the subframe m, the response information of the first data from the second communications device. Specifically, a specific frequency domain resource or several specific frequency domain resources that are in the plurality of frequency domain resources included in the subframe m and that are used for response information transmission may be predefined by a protocol, or may be semi-statically or dynamically configured by the network device. For example, as shown in <FIG>, a first bit map is <NUM>, and therefore, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, and the like are a first resource used for V2X data transmission. A second bit map is <NUM>, and therefore, a subframe <NUM>, a subframe <NUM>, and the like are a second resource used for response information transmission. It can be learned that the subframe <NUM>, the subframe <NUM>, and the like are used for both V2X data transmission and response information transmission. In <FIG>, in the subframe <NUM>, only some frequency domain resources are used for response information transmission. In the subframe <NUM> or the subframe <NUM>, a frequency domain resource may be divided into several frequency domain units. For example, a frequency domain unit may be a subcarrier or a sub-channel. In this case, one or more frequency domain units of the frequency domain resource are used for response information transmission, and a remaining frequency domain unit may be used for data transmission. Therefore, resource utilization efficiency can be improved.

Preferably, the first communications device may dynamically notify, by using control signaling, the second communications device whether a response information feedback needs to be performed on the data sent by the first communications device to the second communications device. If the response information needs to be fed back, the method in step <NUM> is used, and the second communications device feeds back the response information to the first communications device. If the response information does not need to be fed back, a resource used to feed back the response information of the data is released, to be used for other V2X data communication.

Step <NUM>: The receiving unit <NUM> of the first communications device receives, on the second resource, the response information of the first data from the second communications device, and the sending unit <NUM> of the second communications device sends, on the second resource, the response information of the first data to the second communications device. The response information includes ACK information or NACK information. When the first communications device receives the ACK information from the second communications device, the first communications device no longer sends the first data to the second communications device, and therefore, communication resources are saved. When the first communications device receives the NACK information from the second communications device, the first communications device sends the first data to the second communications device again, and therefore, reliability of receiving the first data by the second communications device is improved, and reliable transmission of V2X data between different communications devices is ensured.

The receiving unit <NUM> included in the first communications device may be replaced by a receiver, the determining unit <NUM> may be replaced by a processor, and the sending unit <NUM> may be replaced by a transmitter. The sending unit <NUM> included in the second communications device may be replaced by a transmitter, the determining unit <NUM> may be replaced by a processor, and the receiving unit <NUM> may be replaced by a receiver. The sending unit <NUM> included in the network device may be replaced by a transmitter, the determining unit <NUM> may be replaced by a processor, and the receiving unit <NUM> may be replaced by a receiver. Alternatively, the first communications device, the second communications device, or the network device may be a chip or a system on chip, to complete the method shown in the embodiment of <FIG>.

According to this embodiment of this application, the network device configures, for the first communications device and the second communications device, the second resource that can be used for the response information. The first communications device and the second communications device may transmit the response information on the second resource, and transmission of the response information is implemented in V2X communication.

When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, the integrated unit may be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions of this application essentially, or the part contributing to the prior art, or all or some of the technical solutions may be implemented in a form of a software product. The software product is stored in a storage medium and includes several instructions for instructing a computer device (which may be a personal computer, a server, or a network device) to perform all or some of the steps of the methods described in the embodiments of this application. The foregoing storage medium includes: any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a magnetic disk, or an optical disc.

Claim 1:
A response information sending method, comprising:
receiving (<NUM>), by a first communications device, first indication information from a network device, wherein the first indication information is used to indicate a first resource for V2X communication between the first communications device and a second communications device, wherein the first resource comprises x subframes, wherein x is a positive integer;
sending (<NUM>), by the first communications device in a subframe n, a first data to the second communications device, wherein the subframe n belongs to the x subframes;
receiving (<NUM>), by the first communications device, second indication information from the network device, wherein the second indication information is used to determine a second resource for transmitting by the second communications device ACK/NACK information in response to the first data, wherein the second resource comprises y subframes, the x subframes comprises the y subframes, wherein y is a positive integer and y><NUM>; and
receiving (<NUM>), by the first communications device in a subframe m, the ACK/NACK information in response to the first data from the second communications device, wherein the subframe m belongs to the y subframes, the subframe m is a subframe, after a subframe n+k, with the minimum sequence number in the y subframes of the second resource, wherein the subframe n+k is a kth subframe after the subframe n, k is predefined or is received by the first communications device from the network device, and n, m, and k are all non-negative integers.