Abstract:
A method of a base station may comprise: mapping at least one port of the base station to each of a plurality of user equipments (UEs) to be overloaded; configuring overloading signatures for a code division multiplexing (CDM) scheme; mapping the overloading signatures with the plurality of UEs to be overloaded, respectively; transmitting a message including configuration information of the overloading signatures to the plurality of UEs; and transmitting, to the plurality of UEs, signals multiplexed by the CDM scheme using the overloading signatures.
Abstract:
A method of a terminal may comprise: receiving, from a base station, information on Timing Advance (TA) groups, which are divided into groups, each having a specific unit size, based on a range for TAs occurring within a cell, and information on group-specific scheduling offsets mapped to the TA groups; calculating a pre-compensated TA based on satellite ephemeris information of the base station and location information of the terminal; identifying a group-specific scheduling offset mapped to a TA group corresponding to the pre-compensated TA; and transmitting a first uplink signal including a preamble to the base station using an uplink timing adjusted based on the group-specific scheduling offset.
Abstract:
A handover method and a control transfer method are provided. A handover method of performing an inter-cell handover between a first ground station and a second ground station may include setting a first channel to the second ground station, measuring, by an airborne radio station, a second channel and reporting a measurement result to the first ground station, sending, by the first ground station, a handover request to at least one of a ground control station (GCS) or a control and non-payload communication (CNPC) network, determining, by the at least one of the GCS or the CNPC network, whether to perform a handover, and transmitting, by the at least one of the GCS or the CNPC network, a handover instruction to the airborne radio station based on a result of the determining.
Abstract:
A handover method and a control transfer method are provided. A handover method of performing an inter-cell handover between a first ground station and a second ground station may include setting a first channel to the second ground station, measuring, by an airborne radio station, a second channel and reporting a measurement result to the first ground station, sending, by the first ground station, a handover request to at least one of a ground control station (GCS) or a control and non-payload communication (CNPC) network, determining, by the at least one of the GCS or the CNPC network, whether to perform a handover, and transmitting, by the at least one of the GCS or the CNPC network, a handover instruction to the airborne radio station based on a result of the determining.
Abstract:
A dynamic channel assignment method includes receiving, at a ground control station (GCS), assignment of a first communication channel set from a spectrum authority before takeoff of the unmanned aircraft; receiving, at the GCS, assignment of a second communication channel set when the unmanned aircraft is to move from a first area using the first communication channel set to a second area using the second communication channel set due to a flight plan of the unmanned aircraft after takeoff of the unmanned aircraft; and after the unmanned aircraft enters the second area, maintaining, at the GCS, the first communication channel set when the unmanned aircraft reenters the first area due to the flight plan, and returning, at the GCS, the first communication channel set to the spectrum authority when the unmanned aircraft does not reenter the first area due to the flight plan.
Abstract:
A method of a base station may comprise: receiving a link signal from a satellite; obtaining a first reference time of the satellite from the link signal; configuring a second reference time of the base station based on the first reference time; and transmitting a downlink signal to a terminal based on the second reference time, wherein the satellite belongs to a non-terrestrial network and the base station belongs to a terrestrial network.
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:
Provided a method and a system for increasing system capacity in a multibeam satellite communication system. A signal transmission method of a multilayer-based multibeam structure of a satellite communication system may include generating a multilayer-based multibeam structure; selecting two or more layers for forming a single frequency selective channel; generating a transmission signal by applying the same channel encoding scheme to the two or more selected layer; and transmitting the transmission signal.
Abstract:
Disclosed is a low-rate data transmission method in an LTE based satellite radio interface, which can secure a large number of low-rate data channels which can simultaneously access and increase frequency efficiency while providing compatibility with the existing LTE radio interface through a transmission technique which can secure more link margins in communication between portable terminals (handheld type terminals) without changing a basic LTE transmission frame structure in a satellite system requiring high transmission power.
Abstract:
In a system that performs mobile communication using at least two beams, by determining a size of a beam based on information that is acquired for mobile terminals attempting an access, a beam of a form having an adaptive size is formed and thus communication is performed. A beam sector including a plurality of beam segments and a beam segment that forms a beam of a minimum size within entire coverage is set, and while forming one beam per beam sector, a size of a beam is adaptively determined.