Abstract:
1. 청구범위에 기재된 발명이 속한 기술분야 본 발명은 양방향 위성 통신 시스템에서 적응형 전송 기법을 이용한 순방향 강우감쇠 보상 장치 및 그 방법에 관한 것임. 2. 발명이 해결하려고 하는 기술적 과제 본 발명은, 강우 상태에 있는 단말국들과 정상 상태에 있는 단말국을 분리하여 서로 다른 전송 방식을 사용하는 데이터 프레임을 수신하도록 하여 정상 상태에 있는 단말국들은 데이터 전송 효율이 높은 전송 방식으로 고속의 데이터를 수신하는 동시에, 강우 상태에 있는 단말국들도 데이터 전송 효율은 떨어지지만, 지속적으로 서비스 제공을 받을 수 있도록 하는 양방향 위성 통신 시스템에서 적응형 전송 기법을 이용한 순방향 강우감쇠 보상 장치 및 그 방법을 제공하고자 함. 3. 발명의 해결방법의 요지 본 발명은, 양방향 위성 통신 시스템에서 적응형 전송 기법을 이용한 순방향 강우감쇠 보상 장치에 있어서, 외부의 인터넷 서비스 제공자와 연결되어 해당 위성망을 통해 데이터를 송수신하는 중심국과 단말국의 제한된 자원의 관리 기능을 담당하기 위한 자원 관리수단; 상기 중심국에서 단말국으로 전달되는 데이터를 위성 전송하기 위한 규격인 엠펙-2 전송스트림(MPEG-2 TS) 패킷으로 변환하기 위한 송신 데이터 형식 변환수단; 상기 송신 데이터 형식 변환수단으로부터 출력되는 데이터를 순방향 위성 전송 규격에 맞춰 변조하기 위한 순방향 변조수단; 상기 단말국으로부터의 역방향 신호를 복조하기 위한 역방향 복조수단; 및 상기 역방향 복조수단에서 출력되는 데이터를 IP(Internet Protocol) 데이터그램으로 전환하기 위한 수신 데이터 형식 변환수단을 포함함. 4. 발명의 중요한 용도 본 발명은 이동 위성 통신 시스템 등에 이용됨.
Abstract:
PURPOSE: A symbol timing estimation apparatus according to carrier frequency variation range and a method thereof are provided to estimate symbol timing using an output signal of a matching filter when a carrier frequency variation is small and to estimate it using an input signal of the matching filter when the carrier frequency variation is large. CONSTITUTION: According to the symbol timing estimation apparatus, a filtering unit(100) filters a sampling signal. An information generation unit(210) generates a control signal to determine whether to use an output signal of a signal selection unit(200) as the sampling signal or as a filtering signal from the filtering unit, according to the variation range of a received carrier frequency. The signal selection unit outputs one of the sampling signal and the filtering signal selectively, according to the control signal. And a symbol timing estimation unit(110) estimates the symbol timing of the signal selected by the signal selection unit.
Abstract:
PURPOSE: A backplane device is provided to minimize a mutual electromagnetic interference by separating a TTL signal or a clock signal from a digital IF signal. CONSTITUTION: A power signal pin(110) is configured to transfer a power signal, and a TTL signal pin(120) is configured to transfer a TTL signal. A clock signal pin(130) is configured to transfer a clock signal, and a digital information signal pin(140) is configured to transfer a digital signal including information. A ground pin(150) is disposed between the pins and separates the pins to minimize an electromagnetic interference between signals.
Abstract:
The present invention relates to a method and an adaptive coding modulation apparatus for a forward link for satellite communication. According to an embodiment, the adaptive coding modulation apparatus comprises: a receiving unit for receiving a ratio of signal to noise of a received signal; a decision unit for determining whether the ratio thereof is less than or equal to a threshold; and a process unit for operating a channel prediction algorithm if the ratio thereof is less than or equal to the threshold as a result of the determination. [Reference numerals] (300) Adaptive coding modulation apparatus; (310) Receiving unit; (320) Decision unit; (330) Process unit
Abstract:
PURPOSE: A forward link adaptive transmission device and a method thereof for satellite communication are provided to increase availability of a forward link by determining a modulation and a code rate suitable for channel of each terminal using forward link SNR(Signal to Noise Ratio) information. CONSTITUTION: A transmission device(100) includes a channel estimation unit(110), a control unit(120), a routing unit(130), and a modulation unit(140). The channel estimation unit estimates a channel state by terminal by receiving an SNR from terminals. The control unit confirms predetermined modulation and code rates corresponding to a predetermined section according to the channel state and confirms the modulation and code rate according to the channel state by terminal. The routing unit receives traffic data, confirms a receiving target of the traffic data and classifies the traffic data by the modulation and code rate. The modulation unit modulates the traffic data classified by the predetermined modulation and code rate with a modulation method corresponding to the each modulation and code rate. [Reference numerals] (110) Transmission device; (120) Control unit; (130) Routing unit; (140) Modulation unit; (AA) Traffic data; (BB) FLS information; (CC) End terminal SNR information; (DD) Falsified traffic data
Abstract:
PURPOSE: A satellite broadcasting system and a method thereof are provided to improve a bandwidth in rainfall by simultaneously transmitting the signal of a low resolution by using a spectrum diffusion method. CONSTITUTION: A modulation unit (140) modulates a high image quality signal encoded by a first encoding unit (110) and a middle image quality signal encoded by a second encoding unit (120). A spectrum diffusion modulation unit (150) modulates and generates a spectrum diffusion signal from a low image signal encoded by the second encoding unit. A multiplexer (160) combines the modulated spectrum diffusion signal and the modulated high quality and middle quality signal. [Reference numerals] (110) First encoding unit; (120) Second encoding unit; (130) Third encoding unit; (140) Modulation unit; (150) Spectrum diffusion modulation unit; (160) Multiplexer; (170) Up converter; (AA) Broadcasting signal
Abstract:
PURPOSE: A time delay measuring method of an encoding linearization transmitter is provided to compare a time delay according to a path of a phase signal and an amplitude signal of an input signal in order to measure time delay of an input signal and an output signal of an encoding linearization transmitter. CONSTITUTION: A time delay measurement unit distributes a pulse-modulated sine wave signal into different transmission lines(110). The time delay measurement unit extracts an amplitude modulation signal and a phase modulation signal from the modulated sine wave signal(130). The time delay measurement unit detects an envelope of the amplitude modulation signal.