Abstract:
비균등 16-심볼 신호성상을 이용한 변조기 및 변조 방법이 개시된다. 본 발명의 일실시예에 따른 비균등 16-심볼 신호성상을 이용한 변조기는 부호율이 3/15인 LDPC 부호(LDPC code)에 상응하는 부호어(codeword)를 수신하는 메모리; 및 상기 부호어를 4비트 단위로 비균등 16-심볼 신호성상의 16개 심볼들에 맵핑하는 프로세서를 포함한다.
Abstract:
비균등 16-심볼 신호성상을 이용한 변조기 및 변조 방법이 개시된다. 본 발명의 일실시예에 따른 비균등 16-심볼 신호성상을 이용한 변조기는 부호율이 4/15인 LDPC 부호(LDPC code)에 상응하는 부호어(codeword)를 수신하는 메모리; 및 상기 부호어를 4비트 단위로 비균등 16-심볼 신호성상의 16개 심볼들에 맵핑하는 프로세서를 포함한다.
Abstract:
PURPOSE: A XOR- calculation FEC(Forward Error Correction) for a burst data loss recovery and an unequal error protection method having a HARQ(Hybrid Automatic Repeat request) are provided to effectively recover the burst loss without extending the transmission bandwidth. CONSTITUTION: A forward loss protection packet is produced through an XOR calculation of a base layer packet of a current GoP(Group of Picture) and the base layer packet of the previous 2nth GoP(S10). The forward loss protection packet is added to the last packet of the previous nth GoP(S20). A backward loss protection packet is produced through the XOR calculation of the base layer packet of the current GoP and the base layer packet of the afterward 2nth GoP(S30). The backward loss protection packet is added to the last packet of the afterward nth GoP(S40). [Reference numerals] (AA) Start; (BB) End; (S10) Generating a forward loss protection packet(current GoP base layer packet(XOR) and previous 2n-th GoP base layer packet); (S20) Adding the forward loss protection packet to the last packet of the previous n-th GoP; (S30) Generating a backward loss protection packet(current GoP base layer packet(XOR) and afterward 2n-th GoP base layer packet); (S40) Adding the backward loss protection packet to the last packet of the afterward n-th GoP;
Abstract:
PURPOSE: A data transmitting and receiving apparatus using OFDM(Orthogonal Frequency Division Multiplexing) modulation and a method thereof are provided to have an OFDM property resistant to multipath fading and lower the PAPR(Peak-to-Average Power Ratio) to 0dB. CONSTITUTION: A data transmitting apparatus(100) includes an OFDM modulating unit(110), a PAPR control unit(120) and a signal transmitting unit(130). The OFDM modulating unit generates multiple modulated data symbols by symbol-mapping inputted data and converts the multiple modulated data symbols in a frequency domain into real number signals in a time domain. The PAPR control unit performs angle modulation of the real number signals in the time domain, and then cyclically shifts the angle modulated signals in the frequency domain. The signal transmitting unit transmits the cyclically shifted signals. [Reference numerals] (112) Symbol mapping unit; (121) Scaling unit; (122) Angle modulation unit; (124) FFT unit; (125) Shift unit; (126) IFFT unit; (130) Signal transmitting unit; (AA) Information bit;
Abstract:
PURPOSE: A data transmission scheduling method is provided to maximally increase service quality and user know-how by efficiently using wireless resources. CONSTITUTION: A data receiving device presumes a channel state from a data transmitting device to a data receiving device(410). The data receiving device sets a plurality of buffers to have optimum states for buffers based on the channel state wherein data transmitted from the data transmitting device are buffered(420). The data receiving device controls transmission of each data based on the channel state to maintain the optimum states of the buffers(430,440). The optimum states are a ratio of time for which video information included in the buffered data is reproduced.