Abstract:
Disclosed is a channel assignment method of a communication system for controlling an unmanned aerial vehicle (UAV), the method including receiving assignment data and an interference analysis criterion from a spectrum authority; performing an interference analysis and selecting a control and non-payload communication (CNPC) channel based on the assignment data and the interference analysis criterion; and requesting the spectrum authority for assigning the CNPC channel.
Abstract:
Disclosed herein is a method for configuring a subframe by a transmitting apparatus in a mobile communication system, including: configuring the subframe consisting of a downlink control information transmission interval in which control information of a downlink is transmitted, a data transmission interval in which data are transmitted, an uplink control information transmission interval in which control information of an uplink is transmitted, and a response signal transmission interval in which a response signal to data reception is transmitted; and transmitting the subframe.
Abstract:
A base station defines a short TTI (transmission time interval) equal to the length of one subslot as the minimum unit of a time resource for data transmission in a subframe including a plurality of subslots, determines the RS type the terminal will use for transmission, among a plurality of RS types, based on the positions of RSs (reference signals) within the short TTI, and sends information on the RS type the terminal will use for transmission to the terminal.
Abstract:
A method of providing cooperative communication to a terminal through a plurality of base stations is provided. A plurality of base stations each transmit a midamble to a terminal, and the terminal measures a channel through a received midamble. The terminal transmits information about the measured channel to at least one of the plurality of base stations.
Abstract:
A data relay method includes receiving a relay request from a BS, and when the relay request is accepted, relaying data between the BS and at least one external terminal, or the data relay method includes determining relaying between a first terminal among a plurality of terminals, and other remaining terminals excluding the first terminal among the plurality of terminals, and relaying data between the first terminal and the other remaining terminals.
Abstract:
A synchronization group management apparatus of a node recognizes a node belonging to a different group if groups having mobility are moved and located in the same area, and performs an operation of merging the different groups into one group by changing the frame start time and the synchronization reference time of the node.
Abstract:
A communication apparatus and a data transmission method of the communication apparatus are disclosed. The communication apparatus receives feedback messages corresponding to failed data from receivers, generates a feedback matrix in response to the feedback messages, selects transmission candidate data from the feedback matrix, performs network coding on the transmission candidate data, and transmits retransmission data generated by the network coding to the receivers. Transmission candidate data is selected from the feedback matrix, and network coding is performed on the transmission candidate data to retransmit data to the receivers.
Abstract:
A method and apparatus for synchronizing a carrier frequency of a node included in a distributed network are provided. The apparatus includes a frequency offset estimating unit, an offset average value calculating unit, and a frequency adjustment value calculating unit. The method includes receiving preambles from a plurality of nodes adjacent to the node, estimating offsets of the carrier frequencies from the received preambles for each of the plurality of neighbor nodes, calculating an average value of the estimated offsets, calculating an adjustment value of the carrier frequencies with respect to the entirety of the plurality of neighbor nodes by using the average value, and adjusting a carrier frequency of the node on the basis of the adjustment value.
Abstract:
Provided is a method for transmitting, by a transmitter, a first data having periodicity through a channel of an unlicensed band:The transmitter adjusts at least one of transmission timing of the first data and clear channel assessment (CCA) timing for the channel to occupy the channel. The transmitter determines whether the channel may be occupied by performing a CCA on the channel at the CCA timing. The transmitter transmits the first data through the channel at the transmission timing of the first data, when it is determined that the channel may be occupied.
Abstract:
Disclosed is a method and apparatus for selecting a channel for UAV control and non-payload communication on the basis of a channel interference analysis. According to an embodiment of the present disclosure, provided is a method of selecting a UAV control channel on the basis of an interference analysis, the method including: performing, by a user device, the interference analysis; selecting, by the user device, a channel on the basis of a result of the interference analysis; requesting, by the user device, a central management device to approve the selected channel; and performing, by the user device, communication with a UAV on the channel approved by the central management device.