Abstract:
PURPOSE: A digital quadrature demodulation device is provided where its DC offset is effectively controlled without increasing a complexity while realizing a hardware. CONSTITUTION: An A/D(Analog/Digital) converter(10) receives a receiving signal, and a matching filter(11) receives an output of the A/D converter. A digital interpolation filter(12) receives an output of the matching filter and an output of a symbol timing recoverer(14). A carrier phase detector(13) receives an output of the digital interpolation filter and an output of a carrier recoverer(15). A signal determination part(16) receives an output of the carrier phase detector, and the symbol timing recoverer receives the output of the carrier phase detector and an output of the signal determination part. The carrier recoverer receives the output of the carrier phase detector and the output of the signal determination part. And a DC offset control part(20) receives a recovery signal and a determination signal(symbol). The DC offset control part comprises a DC offset detector(21) receiving the recovery signal and the determination signal, and a loop filter(22) receiving an output of the DC offset detector, and a D/A converter(23) receiving an output of the loop filter.
Abstract:
PURPOSE: A parallel processing device of a decision directed carrier restoration apparatus is provided to increase calculation processing speed by parallel processing method other than sequential processing method. CONSTITUTION: The parallel processing device of a decision directed carrier restoration apparatus has the parallel frequency offset compensating part(101) and the parallel phase offset compensating part(102). The parallel frequency offset compensating part(101) parallel-inputs the carrier signal and compensates for the frequency offset by frequency tracking loop. The parallel phase offset compensating part(102) compensates for the frequency-compensated signal from the parallel frequency offset compensating part(101) by phase tracking loop(PTL).
Abstract:
PURPOSE: A mounted apparatus and a roadside apparatus in Dedicated Short Range Communication(DSRC) system are provided to offer a group or personal a traffic information broadcast as well as additional services by constructing the DSRC system. CONSTITUTION: A parallel/serial converter(104) converts control and message signals received from a mounted device to serial signals. A channel forming device(110) receives the control and message signals from the parallel/serial converter(104), and forms channels. A coder(112) codes the control and message signals and link request signals from the channel forming device(110). A timing recover device(114) detects timing signals from the control signals and samples a symbol timing on the side of roadside. A decoder(122) decodes the coded signal from the received channels. A frame start signal sensor(124) samples a frame from the received channels and informs the mounted apparatus(100) of a start position of the frame. A channel start signal sensor(126) detects a channel start signal from the channels received from a roadside apparatus. A serial/parallel converter(118) converts the control and message signals to parallel signals. A storage(120) interfaces the serial/parallel converter and a controlling part.
Abstract:
PURPOSE: A microstrip antenna surround by a via-hole and a microstrip antenna laminating method using the same are provided to form a cavity through a process of manufacturing a via-hole on a PCB(Printed Circuit Board) and laminating a microstrip antenna surrounded by the via-hole. CONSTITUTION: A plurality of microstrip antenna elements are arranged on PCBs(Printed Circuit Boards). A plurality of via-holes have conductive features with respect to an electromagnetic wave, and are positioned in a circumference of the antenna elements at predetermined intervals, so as to form a cavity. The respective via-holes are a conductive grid structure having an interval below a tenth wave length. The respective via-holes are formed by coating a conductive material on a wall surface of the holes. The via-holes are filled with conductive material inside thereof. The plurality of PCBs are separated with a conductive layer on which a hole is formed. The cavity is formed by the conductive via-holes having the predetermined intervals on the circumference of the microstrip antenna elements.
Abstract:
PURPOSE: A method for efficiently detecting a synchronous byte in an MPEG-2 transport stream is provided to CONSTITUTION: A current state is stored in a register which is a state indicator having three bits size using a current value of bits which continuously are inputted and a previous state of the current value. A synchronous byte signal of eight bits is detected. the synchronous byte signal of which is 01000111, when an MPEG-2 transport stream is inputted in the order of 0-1-0-0-0-1-1-1, a state in the state indicator is In a change of a state indicator having three bit size in an MPEG-2 transport stream increased one by one from a state '1', passes by a state '8', changes to the state '1' to generate the synchronous byte signal. When an MPEG-2 transport stream is not inputted in the order of 0-1-0-0-0-1-1-1, a state in the state indicator is increased one by one from a state '1' but does not go to the state '8'.
Abstract:
본 발명은 엠펙-2(MPEG-2) 전송 스트림(TS:Transport Stream) 재다중화기 및 재다중화 방법에 관한 것으로, TS패킷열 데이터를 입력받아 일시 저장하기 위한 FIFO와, PCR유무를 확인하여 PCR을 포함하고 있는 경우 시간 지연을 계산한 후 PCR을 정정하는 PCR 정정부를 구비하여 복수개로 배열되는 입력 취급기와; 입력 취급기에 클럭을 제공하기 위한 27MHz 오실레이터와; 입력 취급기로부터 FIFO에 저장되어 있는 TS패킷열의 양을 나타내는 상태 정보를 전달받아 스케줄링 알고리즘에 따라 다음에 다중화할 입력 취급기를 결정하고 이를 해당 입력 취급기에게 알려주는 스케쥴러와; 다중화 선택신호를 받은 입력 취급기가 출력 클럭 및 TS 프레임 동기에 맞춰 하나의 TS패킷열을 출력하게 하고, 출력된 TS패킷열에 PCR정보가 포함되어 있는 경우에는 PCR 정정부를 이용하여 원래의 PCR값 위치에 정정된 PCR값으로 대체하여 출력하게 하기 위한 TDM 다중화기로 구성하여 PCR을 정정할 때 모든 입력 전송 스트림패킷열이 동일하게 갖는 최소 지연 시간을 고려하여 PCR값을 정정함으로써 다중화 과정에서 발생하는 램덤한 시간지연에 대해서도 MPEG복호기가 안정적으로 복호과정을 수행할 있게 한다.
Abstract:
본 발명은 위성방송 시스템 지구국에서 강우로 인한 Uplink 신호감쇄를 보상하기 위한 업링크(Uplink) 전력 자동제어 방법에 관한 것이다. 위성방송시스템 송출지구구에서 이용중인 업링크 전력 제어(UPC) 방법은 위성으로부터 수신되는 비콘(beacon)신호를 이용하여 이 신호의 감쇄량 만큼 송출신호의 출력을 증가시킨다. 그런데 기존의 업링크 전력 제어 시스템은 고출력증폭기의 비선형 특성을 고려하지 않음으로써 실제 증가시켜야 할 출력보다 적게 증가 시키는 단점이 있었다. 본 발명은 이러한 고출력증폭기의 비선형 특성을 고려하여 실제 강우로 인하여 감쇄된 신호양 만큼 송출신호를 올려주는 방안을 제시한다.