Patent application number | Description | Published |
20120099521 | CENTER DISTRICT DUAL MODE NETWORK SYNCHRONIZATION ACQUISITION METHOD AND APPARATUS FOR SATELLITE COMMUNICATION SYSTEM - A center district network synchronization acquisition apparatus and method capable of accommodating both a GPS mode based terminal and an NCR mode based terminal. The center district network synchronization acquisition apparatus for a satellite communication system according to an exemplary embodiment includes: a timing generating unit configured to generate an interrupt signal by being synchronized with a PPS (pulse per second) signal received from a reference clock generation module, an NCR counter configured to extract a corresponding NCR (network clock reference) value at a timing indicated by the interrupt signal, and a packet generating unit configured to generate an MPEG2-TS packet including the NCR value extracted according to the interrupt signal. Therefore, this apparatus can accommodate both a GPS mode based terminal and an NCR mode based terminal. As a result, the satellite communication system can operate regardless of the network synchronization mode performed by the terminal. | 04-26-2012 |
20120114029 | METHOD AND APPARATUS FOR MEASURING TIME DELAY IN ENVELOPE ELIMINATION AND RESTORATION TRANSMITTER - Provided are a method and apparatus for measuring a time delay in an envelope elimination and restoration (EER) transmitter. A method of measuring a time delay in an EER transmitter includes receiving a modulated sinusoidal signal and distributing the modulated sinusoidal signal to be transmitted through transmission lines separated from each other, extracting an amplitude modulation signal and a phase modulation signal from the modulated sinusoidal signal, and detecting envelops of the amplitude and phase modulation signals and determining a difference in time between the amplitude and phase modulation signals. In the EER transmitter, to measure a time delay between input and output signals, time delays of paths of amplitude and phase modulation signals of the input signal are compared, thereby determining a difference in time between the amplitude and phase modulation signals. | 05-10-2012 |
20130051693 | ACM-BASED SIMULCAST TRANSMISSION AND RECEPTION APPARATUS AND METHOD - Provided are an adaptive coding modulation (ACM)-based simulcast transmission and reception apparatus and method. The apparatus includes a transmitter configured to analyze whether or not it is raining in a region where a receiver is present on the basis of channel state information (CSI) provided by the receiver, encode and/or modulate an image signal according to the analysis result, and provide the encoded and/or modulated image signal through a single band or multiple bands. On the basis of a result of analyzing whether or not it is raining in a region where a receiver is present, it is possible to effectively prevent signal attenuation caused by rain by providing image signals having different resolutions through multiple bands when the region is in a rainfall state. | 02-28-2013 |
20130077563 | DATA TRANSMISSION AND RECEPTION METHOD AND APPARATUS ROBUST AGAINST PHASE NOISE FOR HIGH EFFICIENCY SATELLITE TRANSMISSION - A data transmission and reception apparatus is used for a high efficiency satellite transmission. The apparatus includes an initial phase calculation unit to calculate initial phase information using a preamble and a postamble of a data packet applied thereto, a symbol transition calculation unit to perform forward and backward metric operations using the initial phase information calculated by the initial phase calculation unit and a pilot symbol in the data packet to calculate a symbol transition of the data packet, and a phase error estimation unit to calculating a phase error using the pilot symbol in a spot where the pilot symbol is positioned, the calculated phase error being provided to the symbol transition calculation unit. | 03-28-2013 |
20130114442 | APPARATUS AND METHOD FOR ESTIMATING CHANNEL BASED ON WEATHER DATA - In a satellite communication system, a central station receives a message including channel measurement information that is provided from a terminal and calculates a channel estimating value based on the received channel measurement information and weather data of a region corresponding to a location of the terminal. The central station determines encoding and modulation methods of data to transmit based on the calculated channel estimating value. | 05-09-2013 |
20130148696 | SATELLITE BROADCASTING SYSTEM AND METHOD - Provided is a satellite broadcasting system and method using a spread spectrum technique to improve satellite broadcasting availability in a rainy environment and to provide a satellite broadcasting N-screen service. A satellite broadcasting transmitter of the satellite broadcasting system may encode a broadcast signal into each of a high definition (HD) signal, a standard definition (SD) signal, and a low definition (LD) signal, may modulate each of the encoded HD signal and the encoded SD signal by a predetermined modulation scheme, may spread a spectrum of the encoded LD signal to generate a spread spectrum signal, may to modulate the spread spectrum signal, may combine the modulated spread spectrum signal with the modulated HD signal and the modulated SD signal to generate a combined modulated signal, and may transmit the combined modulated signal to a satellite. | 06-13-2013 |
20130156136 | APPARATUS AND METHOD FOR ITERATIVE DETECTION AND DECODING IN WIRELESS COMMUNICATION SYSTEM - Provided is an apparatus and method for iteratively detecting and decoding a received signal in a wireless communication system. An apparatus for iterative detection and decoding (IDD) in a wireless communication system may determine a predetermined group to be updated in a first soft decision sequence, may transmit detection control information of the determined group, and may generate a second soft decision sequence based on a detection operation result of a predetermined received signal portion that is extracted based on the detection control information. | 06-20-2013 |
20130194952 | APPARATUS AND METHOD FOR IDENTIFYING TRANSMISSION CONTROL PROTOCOL (TCP) PACKET LOSS - Provided is a method of identifying a transmission control protocol (TCP) packet loss, including transmitting at least one TCP data packet to a TCP receiver, estimating wireless channel status information using the TCP receiver by interaction between a TCP layer and a physical layer, and receiving an acknowledgement (ACK) packet including the estimated wireless channel status information from the TCP receiver. | 08-01-2013 |
20130195148 | MODULATION AND DEMODULATION METHOD FOR SATELLITE COMMUNICATION USING WIDESPREAD SIGNAL-TO-NOISE RATIO (SNR) - 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. | 08-01-2013 |
20140056335 | ADAPTIVE CODING AND MODULATION APPARATUS AND METHOD FOR FORWARD LINK IN SATELLITE COMMUNICATION - An adaptive coding and modulation (ACM) apparatus and method for a forward link in satellite communication is provided. The ACM apparatus may include a receiving unit to receive a signal-to-noise ratio (SNR) of a received signal, a determination unit to determine whether the SNR of the received signal is less than or equal to a threshold value, and a processing unit to execute a channel prediction algorithm when the SNR of the received signal is determined to be less than or equal to the threshold value. | 02-27-2014 |
20140064118 | APPARATUS AND METHOD FOR CONTROLLING SATELLITE TERMINAL - Provided is a satellite terminal controlling apparatus and method that may measure a packet loss rate of a return link at a central station, may determine a modulation and coding (MODCOD) value of the return link using the packet loss rate, and may control MODCOD of a satellite terminal with respect to the return link. | 03-06-2014 |
20140082674 | APPARATUS, SYSTEM, AND METHOD FOR PROCESSING DATA - Provided is a data processing apparatus and method that may initialize baseband frame data that is newly input, and may randomize the baseband frame data based on a byte unit. Also, provided is a data processing system and method that may configure baseband frame data by randomizing the baseband frame data based on the byte unit in performing mode adaptation and stream adaptation with respect to a received transport stream (TS) packet, and may perform channel encoding of the baseband frame data. | 03-20-2014 |
20140082675 | DIGITAL VIDEO BROADCASTING - SATELLITE - SECOND GENERATION (DVB-S2) BASED TRANSMISSION AND RECEPTION APPARATUS AND METHOD OPERABLE IN CIRCUMSTANCES OF LOW SIGNAL TO NOISE RATIO (SNR) - 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. | 03-20-2014 |
20140089766 | APPARATUS AND METHOD FOR LOW DENSITY PARITY CHECK (LDPC) ENCODING - Provided is a low density parity check (LDPC) encoding apparatus and method that may store M registers each including N bits, obtain N×M parity bits by performing a partial parallel operation an N×M number of times with respect to the M registers, and mutually invert subsequent N parity bits periodically, based on previous parity bits for each Nth parity bit of the N×M parity bits, respectively. | 03-27-2014 |
20140150035 | APPARATUS AND METHOD FOR RECEIVING SATELLITE BROADCAST - Provided is an apparatus and a method for receiving a satellite broadcast. The method may include estimating a channel using signal-to-noise ratio (SNR) information being received, determining a video signal to be received among at least two video signals based on the estimated channel, and controlling selective reception of the determined video signal. | 05-29-2014 |
20140233680 | MAP DECODER HAVING LOW LATENCY AND OPERATION METHOD OF THE SAME - Provided is a maximum a posteriori (MAP) decoder having a low latency and an operation method of the MAP decoder, including a branch metric calculation block to calculate a branch metric based on a received signal, a processor control block to demultiplex a received signal in a certain trellis section, an Extrinsec vector, and the calculated branch metric value, and a processor to calculate a path metric entering each state node in a certain trellis section, compensate for the calculated path metric, and calculate a state metric to be applied to a next trellis section based on the compensated path metric. | 08-21-2014 |
20140245361 | MULTILEVEL SATELLITE BROADCASTING SYSTEM FOR PROVIDING HIERARCHICAL SATELLITE BROADCASTING AND OPERATION METHOD OF THE SAME - Provided is a multilevel satellite broadcasting system for providing a hierarchical satellite broadcasting, including a demodulator to demodulate a transmitted multilevel compression stream based on a modulation parameter, a hierarchical video decoder to receive the demodulated multilevel compression stream, and a channel predicting and controlling unit to process at least one of channel prediction and channel control with respect to the demodulated multilevel compression stream based on channel information of the demodulator. | 08-28-2014 |
20150061909 | SYSTEM AND METHOD FOR SYNCHRONIZATION BETWEEN DIGITAL-TO-ANALOG CONVERTERS (DACs) FOR HIGH SPEED SIGNAL PROCESSING - 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. | 03-05-2015 |