Abstract:
A ground radio station (GRS) apparatus and a radio station apparatus included in an unmanned aerial vehicle (UAV) are provided. The GRS apparatus may include an antenna configured to transmit and receive a radio frequency (RF) signal, an RF and/or intermediate frequency (IF) (RF/IF) chain configured to perform a conversion between the RF signal and a baseband signal, a baseband transceiving processor configured to transmit and receive the baseband signal, and a BB-IF interface configured to map the baseband signal to the RF/IF chain or the baseband transceiving processor.
Abstract:
A channel access method in an unmanned aerial vehicle (UAV) control and non-payload communication (CNPC) system is provided. The channel access method may include setting an uplink frequency and a downlink frequency to each of a ground station and an airborne radio station, and performing, by the ground station and the airborne radio station, an initial access using the uplink frequency or the downlink frequency.
Abstract:
A transmitter in a mobile communication system configures a short transmission time interval (TTI) using some transmission symbols in a subframe including a plurality of transmission symbols, multiplexes and transmits a reference signal and some of transmission data in a first symbol of the transmission symbols having the short TTI, and transmits the remainder of the transmission data in the remaining symbols except the first symbol.
Abstract:
A method and an apparatus for allocating uplink resources includes transmitting an uplink grant (UL Grant) for an unlicensed component carrier (UCC) to a plurality of terminals, wherein the UL Grant for a first terminal among the plurality of terminals includes a resource allocation information in which a transmission timing of the uplink data of a second terminal among the plurality of terminals is considered.
Abstract:
A target terminal in a mobile communication system transmits a first uplink cooperative MIMO signal in a first uplink subframe to a cooperating device selected from among a plurality of repeaters for relaying signals and a plurality of terminals except a target terminal for cooperative MIMO transmission and reception, and transmits a second uplink cooperative MIMO signal directly in a second uplink subframe to a base station. The cooperating device amplifies the first uplink cooperative MIMO signal and transmits an amplified first uplink cooperative MIMO signal in the second uplink subframe to the a base station.
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 herein are a method of beamforming and a 3D antenna array. The method includes: transmitting a first control channel; receiving first feedback information on a first antenna set and a first precoding scheme of a plurality of antenna sets included in the 3D antenna array, which are determined based on the first control channel, from a first communication node different from the communication node; and beamforming a traffic channel to be transmitted to the first communication node using the first antenna set and the first precoding scheme.
Abstract:
A transmit node receives a transformed correlation matrix or a correlation matrix of a channel coefficient matrix, or a correlation matrix of an interference channel coefficient matrix from each of receive nodes sharing a radio resource. The transmit node determines a precoder based on a value maximizing values determined by the transformed correlation matrix or the correlation matrix of the channel coefficient matrix, or a value minimizing values determined by the correlation matrix of the interference channel coefficient matrix, and precodes a transmit signal by using the determined precoder.
Abstract:
A method for a first terminal communicating with a base station to perform direct communication with a second terminal is provided. The first terminal determines first timing for transmitting or receiving a first signal to or from the base station. Next, the first terminal determines second timing for transmitting a second signal for terminal discovery to the second terminal. When the first timing and the second timing overlap, the first terminal then changes either the first timing or the second timing.
Abstract:
Disclosed is an authentication method of a wireless mesh network capable of reducing overload and communication delay during authentication procedure by performing authentication between nodes without accessing an authentication server. The authentication method of a wireless mesh network according to an exemplary embodiment of the present disclosure includes: selecting, by a new node, a first neighbor node among one or more adjacent nodes; transmitting, by the new node, an authentication request message including a public key of the new node; authenticating, by the first neighbor node, the public key of the new node; transmitting, by the first neighbor node, an authentication response message including a public key of the first neighbor node to the new node; and authenticating, by the new node, the public key of the first neighbor node; transmitting, by the new node, an authentication identification message to the first neighbor node.