Abstract: Systems and methods for User Equipment (UE) synchronization for Device-to-Device (D2D) out-of-coverage communication are provided. In an embodiment, a method in an in-coverage (IC) UE for the IC UE to become a synchronization source for out-of-coverage UEs for D2D communication includes obtaining, by the IC UE scanning parameters; scanning, by the IC UE, for out-of-coverage synchronization signals; transmitting, by the IC UE, a measurement report to a Transmission Point (TP) in response to a report trigger, the measurement report comprising information of one or more received out-of-coverage synchronization signals; receiving, by the IC UE, a configuration command from the TP instructing the IC UE to become a synchronization source in response to a configuration command from the TP; and transmitting, by the IC UE, a D2D synchronization signal (SS) for a duration of time or until instructed not to do so by the TP.

Abstract: A communication method and a communications apparatus are disclosed. In the communication method, a first terminal obtains a resource period parameter, where the resource period parameter is sent by a network-side device or preconfigured by the first terminal. The resource period parameter includes a period duration of each of at least one resource. The first terminal determines a start time unit of a resource period, and the first terminal sends communication data according to the start time unit of the resource period and the resource period parameter.

Abstract: A communication method, a network side device, and a terminal are provided. In the method, a network side device selects one group of values from at least two preset groups of values for a transmission parameter set; the network side device sends the selected group of values; and a terminal sends communication data based on the group of values of the at least two groups of values of the transmission parameter set. The present invention can adapt to different system statuses and service requirements, thereby improving transmission performance.

Abstract: Systems and methods for User Equipment (UE) synchronization for Device-to-Device (D2D) out-of-coverage communication are provided. In an embodiment, a method in an in-coverage (IC) UE for the IC UE to become a synchronization source for out-of-coverage UEs for D2D communication includes obtaining, by the IC UE scanning parameters; scanning, by the IC UE, for out-of-coverage synchronization signals; transmitting, by the IC UE, a measurement report to a Transmission Point (TP) in response to a report trigger, the measurement report comprising information of one or more received out-of-coverage synchronization signals; receiving, by the IC UE, a configuration command from the TP instructing the IC UE to become a synchronization source in response to a configuration command from the TP; and transmitting, by the IC UE, a D2D synchronization signal (SS) for a duration of time or until instructed not to do so by the TP.

Abstract: An embodiment of a system for operating a communications controller for a group of user equipments engaged in a DMC link in a wireless communications system is provided. The communications controller is configured to allocate a set of subframes in one periodic group of subframes to the group of UEs for the DMC link, signal the set of allocated subframes to the group of UEs, and transmit parameters related to a group of HARQ processes of the DMC link. In an embodiment, the communication controller uses HARQ processes for cellular UE transmission that are determined independently from HARQ processes of the group of HARQ processes for the DMC link, and the parameters are configured to enable the group of UEs to manage the group of HARQ processes for the DMC link.

Abstract: The present invention discloses a D2D synchronization method, user equipment, and a serving cell. The method includes: acquiring, by user equipment, synchronization control information of a serving cell; acquiring an identity of a first synchronization signal sent by a first synchronization source that is obtained through searching on a second transmission carrier frequency, and signal quality of the first synchronization source; determining, according to the identity of the first synchronization signal, the signal quality of the first synchronization source, and the synchronization control information, whether to start to send a synchronization signal; sending, by the user equipment, a second synchronization signal on a third transmission carrier frequency whose frequency is different from a frequency of a carrier frequency of the serving cell, so that a problem of synchronization between different user equipments in a multi-carrier frequency transmission scenario can be resolved.

Abstract: An embodiment of a system for operating a communications controller for a group of user equipments engaged in a DMC link in a wireless communications system is provided. The communications controller is configured to allocate a set of subframes in one periodic group of subframes to the group of UEs for the DMC link, signal the set of allocated subframes to the group of UEs, and transmit parameters related to a group of HARQ processes of the DMC link. In an embodiment, the communication controller uses HARQ processes for cellular UE transmission that are determined independently from HARQ processes of the group of HARQ processes for the DMC link, and the parameters are configured to enable the group of UEs to manage the group of HARQ processes for the DMC link.

Abstract: A method for operating a user equipment (UE) in a UE group including at least two UEs includes receiving, from a communications controller, network resources information about an allocation of a first set of network resources to the UE group and a transmission indication, where the transmission indication indicates that the UE is selected to transmit in a second set of network resources that is a subset of the first set of network resources. The method further includes transmitting, to other UEs in the UE group utilizing a direct mobile communications (DMC) link associated with the communications controller, a first message including a control indicator in a first subset of the second set of network resources, the control indicator indicating scheduling information for a second subset of the second set of network resources.

Abstract: An embodiment of a system for operating a communications controller and a user equipment in a wireless communications system is provided. The communications controller is configured to allocate a first set of subframes to a group of UEs for a DMC link, allocate a second set of subframes to a particular UE in the group of UEs, transmit a first message including information about the first set of subframes to the group of UE, and transmit a second message including information about the second set of subframes to the particular UE. The second set of subframes is a subset of the first set of subframes, and information about the second set includes subframes in which the particular UE may transmit to other UEs in the group of UEs. Subframes in the first set not in the second set are allocated for reception by the particular UE.

Abstract: An embodiment of a system for operating a communications controller for a group of user equipments engaged in a DMC link in a wireless communications system is provided. The communications controller is configured to allocate a set of subframes in one periodic group of subframes to the group of UEs for the DMC link, signal the set of allocated subframes to the group of UEs, and transmit parameters related to a group of HARQ processes of the DMC link. In an embodiment, the communication controller uses HARQ processes for cellular UE transmission that are determined independently from HARQ processes of the group of HARQ processes for the DMC link, and the parameters are configured to enable the group of UEs to manage the group of HARQ processes for the DMC link.

Abstract: Embodiments of the present invention disclose a method and an apparatus for transmitting a synchronization signal. The method of the present invention includes: determining, by a first terminal, a D2D type, where the D2D type includes D2D discovery and D2D communication; and transmitting, by the first terminal, a synchronization signal according to the determined D2D type. Therefore, synchronization signals transmitted by terminals of different D2D types do not affect each other, avoiding that a second terminal detects and receives a synchronization signal that does not correspond to a D2D type of the second terminal and ensuring that user direct-connection communication can be performed correctly and efficiently.

Abstract: A method includes: transmitting, by a transmitting user equipment (UE), scheduling signaling to a receiving UE, where the scheduling signaling includes frequency domain resource information, a quantity of cycles that can be occupied, or transmission pattern information. The method further includes transmitting, by the transmitting UE, user data to the receiving UE according to the scheduling signaling, so that the receiving UE receives the user data according to the scheduling signaling.

Abstract: Embodiments of the present disclosure disclose an information transmission method and apparatus and relate to the field of communications technologies, which can initialize a sequence generator during device-to-device communication, reduce time of transmitting data between a transmitter and a receiver, and save transmission resources. The method of the present disclosure includes: initializing, by a transmitter, a sequence generator according to a synchronization source ID, a group ID, and a timeslot number, scrambling to-be-transmitted information according to a pseudo random binary sequence generated by the sequence generator, and transmitting scrambled to-be-transmitted information; and receiving, by a receiver, the scrambled to-be-transmitted information transmitted by the transmitter, and descrambling the scrambled to-be-transmitted information transmitted by the transmitter. The present disclosure is applied to a scenario in which a transmitter scrambles and transmits to-be-transmitted information.

Abstract: Embodiments of the present invention provide a resource configuration method and an apparatus. User equipment (UE) includes a receiving module and a processing module, where the receiving module is configured to receive a broadcast message sent by a control node and including at least one first resource pool, where the control node is a base station serving the UE or a group head UE of a group to which the UE belongs. The processing module is configured to receive a device to device (D2D) service or send a D2D service by using a resource in the at least one first resource pool.

Abstract: The present invention discloses a method for sending a preamble sequence and user equipment.

Abstract: Embodiments are provided reducing interference between cellular and direct mobile communication (DMC) links in wireless systems. In embodiment, a method performed by a network controller includes sending, to a second network controller, information of resources for a first set of DMC links between DMC user equipments (UEs). The first set of DMC links is associated with the network controller. The method further includes receiving second information of resources for a second set of DMC links associated with the second network controller. The network controller coordinates with the second network controller the allocation of network resources for the first set of DMC links between the DMC UEs. The network resources comprise cellular and DMC resources.

Abstract: An embodiment of a system for operating a communications controller for a group of user equipments engaged in a direct mobile communication (“DMC”) link in a wireless communications system is provided. The communications controller is configured to allocate a set of subframes to the group of UEs for the DMC link, signal the set of allocated subframes to the group of UEs, and signal a length of a sliding window to the group of UEs. In an embodiment, ACK/NACK feedback for communications over the DMC link is aggregated according to the length of the sliding window, and the ACK/NACK feedback for the communications over the DMC link is determined independently from ACK/NACK feedback for cellular transmission between the communication controller and the group of UEs. In an embodiment, the length of the sliding window is a number of subframes.

Abstract: An embodiment of a system for operating a communications controller for a group of user equipments engaged in a DMC link in a wireless communications system is provided. The communications controller is configured to allocate a set of subframes in one periodic group of subframes to the group of UEs for the DMC link, signal the set of allocated subframes to the group of UEs, and transmit parameters related to a group of HARQ processes of the DMC link. In an embodiment, the communication controller uses HARQ processes for cellular UE transmission that are determined independently from HARQ processes of the group of HARQ processes for the DMC link, and the parameters are configured to enable the group of UEs to manage the group of HARQ processes for the DMC link.

Abstract: Systems and methods for User Equipment (UE) synchronization for Device-to-Device (D2D) out-of-coverage communication are provided. In an embodiment, a method in an in-coverage (IC) UE for the IC UE to become a synchronization source for out-of-coverage UEs for D2D communication includes obtaining, by the IC UE scanning parameters; scanning, by the IC UE, for out-of-coverage synchronization signals; transmitting, by the IC UE, a measurement report to a Transmission Point (TP) in response to a report trigger, the measurement report comprising information of one or more received out-of-coverage synchronization signals; receiving, by the IC UE, a configuration command from the TP instructing the IC UE to become a synchronization source in response to a configuration command from the TP; and transmitting, by the IC UE, a D2D synchronization signal (SS) for a duration of time or until instructed not to do so by the TP.

Abstract: An embodiment of a system for operating a communications controller for a group of user equipments engaged in a DMC link in a wireless communications system is provided. The communications controller is configured to allocate a set of subframes in one periodic group of subframes to the group of UEs for the DMC link, signal the set of allocated subframes to the group of UEs, and transmit parameters related to a group of HARQ processes of the DMC link. In an embodiment, the communication controller uses HARQ processes for cellular UE transmission that are determined independently from HARQ processes of the group of HARQ processes for the DMC link, and the parameters are configured to enable the group of UEs to manage the group of HARQ processes for the DMC link.