Abstract:
Provided is a technology applicable to a broad signal to noise ratio (SNR) environment for a satellite communication and broadcasting service, including a mapper to modulate a forward error correction frame based on a predetermined constellation, a physical layer header processor to add a physical layer header to the modulated forward error correction frame, a physical layer frame spreader to spread a physical layer frame of the modulated forward error correction frame, and a physical layer scrambler to scramble the added physical layer header and the spread physical layer frame.
Abstract:
Provided is a satellite broadcasting and communication transmitting apparatus and method for a broadband satellite broadcasting and communication service, including a forward error correction (FEC) encoder to generate an FEC frame, a bit mapping framer to perform bit mapping on the generated FEC frame, and a predistorter to predistort the bit mapped frame.
Abstract:
Provided is a data transmitting and receiving apparatus that may process a signal to be transmitted using a faster-than-Nyquist (FTN) method. The data transmitting and receiving apparatus may perform low-density parity-check (LDPC) encoding on data to be transmitted using a first matrix having a first degree based on a preset reference and a second matrix having a single diagonal matrix structure, independently perform interleaving and symbol mapping on each of an information bit and a parity bit of the data, accelerate an output signal by a transmission rate based on the FTN method, and transmit the data.
Abstract:
Provided is a digital video broadcasting-satellite-second generation (DVB-S2) based transmission and reception apparatus and method operable in circumstances of a low signal to noise ratio (SNR), the DVB-S2 based transmission and reception apparatus including a DVB-S2 based transmitter, a mapping unit to determine bit mapping based on at least one of a state of a transmission channel and an area to be applied, and a physical layer frame (PLframe) replica processing unit to repeat a PLframe in which a physical layer header (PLheader) corresponding to a spreading factor (SF) is inserted.
Abstract:
Provided are a modulation method and a demodulation method for satellite communication using a widespread signal-to-noise ratio (SNR), the method including: adding a dummy frame to a broadcasting/communication signal frame for signal transmission of a digital video broadcasting-satellite second generation (DVB-S2) modulator; verifying a spreading factor; adding the same physical layer header to the broadcasting/communication signal frame to which the dummy frame is added, repeatedly the number of times corresponding to the verified spreading factor; and repeating the same data, for example, PL frame data as the physical layer header.
Abstract:
The present invention relates to a method for transmitting a synchronization signal block (SSB) through a plurality of satellites from a base station that can connect to a plurality of gateways, wherein the method may comprise the steps of: controlling transmission of first SSBs corresponding to the number of beams of each satellite through respective transmission beams in a first SSB cycle; determining a transmission beam of each of the satellites on the basis of a first measurement report for the respective beams received from a terminal; and controlling transmission of second SSBs for determining one combination including two or more gateways among the plurality of gateways in a second SSB cycle.
Abstract:
Provided is a system and method for synchronization between digital-to-analog converters (DAC) for high speed signal processing. A synchronization method of a multi-DAC apparatus may include: inputting a clock to a multiplexer (MUX) DAC; dividing the clock into a first clock and a second clock; transferring a phase difference between the first clock and the second clock to a D flip-flop; and synchronizing the first clock and the second clock by processing the phase difference.
Abstract:
Disclosed are a method and apparatus for a measurement operation in a communication system. The method for a terminal comprises the steps of: receiving measurement configuration information from a base station; identifying a point in time of start of a measurement gap on the basis of the measurement configuration information; identifying the length of the measurement gap on the basis of the measurement configuration information; and performing a measurement operation in the measurement gap, wherein the measurement gap is configured in units of slots, the point in time of start of the measurement gap is a start slot, and the measurement gap includes one or more slots.
Abstract:
A method according to an embodiment of the present invention corresponds to a method for transmitting, by a gateway, a synchronization signal block (SSB) through a plurality of satellites, and may comprise the steps of: determining satellite identification SSBs for identifying a plurality of satellites, respectively; determining beam identification SSBs for identifying beams usable for the plurality of satellites, respectively; and controlling the satellite identification SSBs and the beam identification SSBs to be transmitted to the plurality of satellites, respectively, through a predetermined resource, wherein the satellite identification SSBs and each of the beam identification SSBs have different SSB indices from each other.
Abstract:
An operation method of an IoT terminal performing communications with a satellite may comprise: receiving a first signal from the satellite; determining a number of symbols constituting a preamble based on the first signal; generating a first frame including a preamble generated according to the determined number of symbols, and transmitting the generated first frame to the satellite; and generating a second frame including a preamble generated according to the determined number of symbols when a response signal to the first frame is received from the satellite, and transmitting the generated second frame to the satellite.