Abstract:
디지털 송수신 시스템에서 적응/가변형 변복조 장치를 제안한다. 본 발명의 실시 예에 따른 디지털 송신 시스템에서 적응/가변형 변조하는 물리계층 송신장치는 비트 스트림을 수신하면 이를 기설정한 방법에 따라 저밀도 패리티 점검(Low Density Parity Check; LDPC) 부호화할 비트 스트림과 부호화하지 않을 비트 스트림으로 분류하는 분류부; 상기 부호화하지 않을 비트 스트림을 기설정한 비트 수로 그룹화하여 비부호화 비트 그룹을 출력하는 비부호화 비트 그룹부; 상기 부호화할 비트 스트림을 LDPC 부호화하여 부호화 비트 스트림을 출력하는 LDPC 인코더; 상기 부호화 비트 스트림을 기설정한 비트 수로 그룹화하여 부호화 비트 그룹을 출력하는 부호화 비트 그룹부; 상기 부호화 비트 그룹을 이용하여 심볼부분집합(coset)을 선택하고 상기 비부호화 비트 그룹을 이용해서 상기 선택한 심볼부분집합에서 심볼을 결정하는 직교진폭 변조부; 및, 상기 직교진폭 변조부에서 결정한 심볼을 컨볼루셔널 인터리빙하는 컨볼루셔널 인터리버를 포함한다.
Abstract:
PURPOSE: A forward error correction encoding/decoding method, digital broadcasting reception apparatus and decoding method thereof are provided to offer low-rank compatibility by applying encoding/decoding to payload after dividing header of packet stream. CONSTITUTION: A header separating unit(210) divides a first header part from a packet stream. A block interleaver(221) performs a block interleaving of a first payload. In order that a parity packet according to the preset encoding rate is included, a systematic encoder(223) encodes the block-interleaved first payload part. A block deinterleaver(225) generates a second payload part by block deinterleaving of the encoded first payload part. A header coupling unit(240) unites the first header part, and the second header part and the second payload portion.
Abstract:
PURPOSE: An adaptable/variable type modulating and demodulating apparatus in a digital cable transceiving system is provided to enhance channel equalization performance occurring in higher-order modulation and demodulation. CONSTITUTION: A QAM(Quadrature Amplitude Modulation) unit(313) determines a symbol using a non coding bit group. A convolutional interleaver(315) convolutionally interleaves the determined symbol. A training sequence symbol generating unit(317) outputs one predetermined training sequence symbol.
Abstract:
패킷 수준의 순방향 오류 정정 부호화 및 복호화 방법과 그 장치, 디지털 방송 수신 시스템의 복호화 방법 및 디지털 방송 수신 장치에 관한 기술이 개시된다. 이러한 기술에 따르면, 입력된 패킷 스트림으로부터 제1헤더부를 분리하는 단계; 상기 제1헤더부가 분리된 상기 패킷 스트림의 제1페이로드부를 기 설정된 부호화율에 따라 부호화하여 제2페이로드부를 생성하는 단계; 상기 부호화율에 따라 제2헤더부를 생성하는 단계; 및 상기 제1헤더부, 상기 제2헤더부 및 상기 제2페이로드부를 결합하는 단계를 포함하는 순방향 오류 정정 부호화 방법이 개시된다.
Abstract:
PURPOSE: An adaptation/variable type modulating and demodulating apparatus in a digital cable transceiving system is provided to perform error correction by LDPC(Low Density Parity Check), thereby transmitting a large amount of information at limited bandwidth. CONSTITUTION: A classifier(305) classifies bit streams. A non coding bit group unit(307) outputs a non coding bit group. An LDPC encoder outputs a coded bit stream. A convolutional interleaver(315) convolutionally interleaves a determined symbol.
Abstract:
An optimum TCM(Time Compression Multiplexing) CODEC search method for dual stream systems and an encoder/decoder using the same are provided to perform additional coding for robust data having 1/2 transmission rate, thereby generating robust data of 1/4 transmission rate and searching an optimum codec. An optimum TCM CODEC search method for dual stream systems includes the steps of determining a mixed pattern of general and robust data(910), determining trellis structure of the robust data employed in the mixed pattern according to connection relation of an encoder(920), composing a trellis structure for dual stream in which the trellis structure of the normal data and the determined robust data are mixed(930), computing free distances from each starting point of the trellis structure for the dual stream according to free distance computation finishing conditions for the dual stream(940), and determining an optimum TCM CODEC with reference to the computed free distances(950).
Abstract:
PURPOSE: An adaptive encoding/decoding device in a cable transceiving system is provided to perform decoding adaptively by combining 64-QAM, 256-QAM and 1024-QAM into one circuit. CONSTITUTION: A de-multiplexer(110) divides a QAM symbol into I component and Q component. An I component decoder(120) decodes a bit in which I component is encoded. I component restores I component signal of the 4 quadrant. A Q component decoder decodes a bit in which Q component is encoded. The Q component decoder restores Q component signal of 4 quadrant. A demapper(140) outputs uncoded bits.
Abstract:
A trellis coded modulation encoder estimation method suitable for a dual stream transmission and an encoding apparatus using the same are provided to lower a signal to noise ratio to satisfy a threshold of visibility by improving a receiving performance for robust data and normal data. A trellis coded modulation encoder estimation method suitable for a dual stream transmission includes the steps of: setting the number of memory elements for an encoder, a free distance condition for robust data, and a free distance condition for a mixture stream of the robust data and normal data(110); calculating 1/2 rate encoder combination which maintains to be compatible with a general trellis encoder(120); calculating encoder combination H which satisfies the free distance condition for the robust data, and the free distance condition for the mixture stream of the robust data and the normal data of the 1/2 rate encoder combination(130); calculating a connection element of the memory element which satisfies the encoder combination H and an input/output signal(140); and constructing the encoder according to the connection relation of the memory element and the input/output signal(150).