Abstract:
본 발명의 일 실시 예에 따른 송신 장치는, 스트림을 입력받아 NCR(Network Clock Reference) 패킷이 삽입된 데이터 필드를 생성하는 모드 적응부, 데이터 필드를 이용하여 PL(Physical Layer) 프레임을 생성하고, PL 프레임의 SOF(Start Of Frame)가 검출되면 SOF 플래그를 생성하는 PL 프레이밍부, SOF 플래그 생성 시점의 NCR 값을 출력하는 NCR 카운터, NCR 카운터에서 출력되는 NCR 값을 저장하는 NCR 레지스터 및 PL 프레임을 변조하는 변조기를 포함하며, 모드 적응부는, 데이터 필드를 출력하기 전 NCR 패킷의 NCR 값을 NCR 레지스터에 저장된 NCR 값으로 업데이트 할 수 있다.
Abstract:
The present invention relates to a multi-layered satellite broadcasting system for providing a hierarchical satellite broadcast. The multi-layered satellite broadcasting system, according to an embodiment of the present invention, comprises a demodulator for a multi-layered compressed stream transmitted based on a modulation parameter; a hierarchical video decoder for receiving the demodulated multi-layered compressed stream; and a channel prediction and control unit for processing either channel prediction or channel control (or both) for the demodulated multi-layered compressed stream based on the channel information of the demodulator.
Abstract:
The present invention relates to an apparatus and method for transmitting satellite broadcasting communication for a broadband satellite broadcasting and communication service. The apparatus according to the present invention includes a forward error correction (FEC) encoding unit which generates a forward error correction (FEC) frame, a bit mapping framing unit which performs bit mapping framing of the generated FEC frame, and a predistortion unit which performs the predistortion of the frame which is processed by the bit mapping framing.
Abstract:
The present invention relates to an apparatus and a method of transmitting and receiving based on a DVB-S2 standard which is operational in an environment of a low signal-to-noise ratio. The present invention comprises: a transmitter of the DVB-S2 standard base; a mapping unit to determine a bit mapping based on at least one among the area to be applied and the state of transmission channel; and a physical layer frame iteration unit repeating a physical layer frame where a physical layer header is inserted as a spreading factor.
Abstract:
PURPOSE: An apparatus for estimating the DOA(Direction Of Arrival) and TOA(Time Of Arrival) of a mobile signal and a method thereof are provided to separate a received signal in order to reduce the complexity and to estimate the DOA and TOA of the mobile signal having low complexity using a pseudo-spectrum calculation which uses DFT(Discrete Fourier Transform). CONSTITUTION: A separating unit(210) separates a received signal into DOA vectors and TOA vectors. A correlation matrix calculation unit(220) calculates the correlation matrix of the DOA and the correlation matrix of the TOA. An Eigen Vector Decomposition(EVD)(230) receives the correlation matrix of the DOA and TOA and checks the number of paths through which the received signal is received. A spectrum calculation unit(240) calculates a pseudo-spectrum using DFT. A total calculation unit(250) calculates a TOA spectrum. A sensing unit(260) senses the discrete spatial frequency of the DOA when having a maximum DOA spectrum value and the discrete spatial frequency of the TOA having a maximum TOA spectrum value. A mapping unit(270) calculates the corresponding DOA and TOA. [Reference numerals] (210) Separating unit; (220) Correlation matrix calculation unit; (230) Eigenvector analysis unit; (240) Spectrum calculation unit; (260) Sensing unit; (270) Mapping unit;
Abstract:
PURPOSE: A frame synchronization apparatus in a satellite communication system and method thereof are provided to calculate a correlation between an input signal for synchronizing a frame at a reception end of a satellite communication system and a signal sequence of the reception end without using a multiplier factor. CONSTITUTION: A correlation unit(110) acquires a correlation value between the unique word of a receiver and a symbol data string of a frame received from a transmission end of a satellite communication system. A comparison unit(130) compares the correlation values and the pre-established threshold values. A determination unit(150) determines whether the frame is synchronized according to a comparison result of the comparison unit.
Abstract:
PURPOSE: A method for demodulating signals in a return link of a satellite system and a demodulating apparatus thereof and a method for modulating signals in the return link and a modulating apparatus thereof are provided to check a symbol of a burst signal in a reception terminal by modulating the burst signal in a transmission terminal of a return link in a satellite system. CONSTITUTION: The symbol timing of burst, which is received through a return link of a satellite system, is estimated. The estimated symbol timing of the received burst is synchronized by reference symbol timing(110). An Oerder & Myer algorithm of a non data-aided method is used to estimate a symbol timing error. A location of timing synchronous burst is synchronized to a reference burst location(150) by using a preamble symbol and a postamble symbol of the timing synchronous burst synchronized by symbol timing(130). A carrier wave of the location synchronous burst is recovered by using a pilot symbol of the location synchronous burst synchronized to the reference burst location.
Abstract:
본 발명은 양방향 위성 송수신 시스템에서 IP 패킷을 캡슐화하지 않고 직접 전송하고, 단말국에서 이러한 데이터를 정상적으로 수신하도록 하기 위한 적응형 패킷 스케줄링 장치 및 수신 장치와, 송신 방법 및 수신 방법에 관한 것으로, 양방향 위성통신 시스템에서 통신 데이터(IP 패킷)를 비캡슐화하여 전송하기 위한 적응형 패킷 스케줄링 장치에 있어서, 입력된 IP 패킷을 분류하여 복수의 데이터 큐에 저장하는 분류수단; 상기 데이터 큐에 저장된 상기 IP 패킷의 스케줄링을 수행하고, 결정된 전송방식에 따른 베이스밴드 프레임 길이 단위로 상기 IP 패킷을 잘라 출력하는 스케줄러 및 프레이밍수단; 및 각 단말국에 연결된 모든 사용자 단말에 대한 IP 주소를 상기 각 단말국으로부터 획득하여 관리하고, 상기 입력된 IP 패킷의 목적지 주소 및 상기 각 단말국의 채널 수신 상태 정보에 따라 상기 분류수단 및 상기 스케줄러 및 프레이밍 수단을 제어하는 제어정보 관리수단을 포함하되, 상기 분류수단은, 전송방식별로 구분된 데이터 큐에 상기 제어정보 관리수단으로부터 전달된 IP 주소에 따른 전송방식에 따라 상기 입력된 IP 패킷을 구분하여 저장하고, 상기 스케줄러 및 프레이밍수단은 베이스밴드 프레임 길이 단위로 상기 IP 패킷을 읽어 순방향링크 변조기로 출력하여 상기 IP 패킷이 전송스트림으로 캡슐화되지 않고 베이스밴드 프레임 길이 단위의 연속된 IP 패킷 스트림으로 전송되도록 한다. 위성, 적응형 패킷 스케줄러, 중심국, 단말국, 순방향링크, 역방향링크, 트래픽, IP 패킷