Abstract: Disclosed are a graceful degradation-forward error correction method and an apparatus for performing same. A graceful degradation-forward error correction method determines an encoding unit data group constituted by a predetermined number of time intervals for a data stream input in a time-sequential manner, determines a reference data group to be used in generating a parity frame in each time interval of the encoding unit data group, generates a parity frame using the determined at least one reference data group, and assigns the generated parity frame to at least one time interval from among a plurality of time intervals including time intervals constituting the encoding unit data group based on a predetermined rule. Thus, a lost packet can be recovered even when the packet of a continuous long interval is lost, and consequentially, a seamless service may be provided.

Abstract: Modulation is performed on a first input signal and a second input signal to be transmitted based on symbol mapping. Phase values of the first and second modulated input signals are selectively adjusted. Angle modulation is performed on the first input signal and the second input signal having selectively adjusted phase values. The angle-modulated first and second input signals are transmitted.

Abstract: Provided are a method of packetizing encoded symbols and an apparatus using the same. The method includes an encoded symbol and target packet selection step of deciding a first source symbol and selecting an unpacketized first encoded symbol and a target packet into which the unpacketized first encoded symbol is inserted if there is the unpacketized first encoded symbol of at least one first encoded symbol, which is an encoded symbol of the first source symbol generated using an AND-OR tree structure, and a packetization step of generating a second source symbol based on at least one unpacketized first encoded symbol by use of the AND-OR tree structure, generating at least one second encoded symbol based on the second source symbol by use of the AND-OR tree structure, and packetizing at least one of second encoded symbols into the target packet along with the first encoded symbol.

Abstract: Provided is an apparatus and method for analyzing identification (ID) signals by converting radio frequency (RF) signals which are transmitted with an ID signal added thereto by a transmitting part, e.g., a plurality of transmitters or repeaters, into signals of a desired band; creating ID signals that are identical to the ID signals added to the RF signals; calculating correlation values between the converted signals and the created ID signals based on partial correlation; and extracting channel profile of multi-path signals caused by a channel between the transmitting part and the ID signal analyzing apparatus from the correlation value. The technology of the present research is applied to broadcasting and communication.

Abstract: Provided are a transmitting and receiving system for non-realtime based digital realistic broadcasting, and a method thereof. The transmitting system includes a broadcasting TS generator for generating a 2-D TS for a 2-D image and an auxiliary TS for auxiliary information necessary for realistic broadcasting of the 2-D image, and a transmitter for transmitting the generated auxiliary transport stream before a corresponding broadcasting time and transmitting the generated 2-D transport stream according to a corresponding broadcasting schedule.

Abstract: A data transmission apparatus is provided. A symbol mapper performs symbol mapping on information about an optimum key index that instructs a modified Walsh-Hadamard matrix that causes a minimum peak-to-average power ratio and generates a plurality of key symbols. A modified Walsh-Hadamard transformer generates a plurality of modified Walsh-Hadamard-transformed data symbols by performing modified Walsh-Hadamard transform on a plurality of data symbols according to a modified Walsh-Hadamard matrix that an optimum key index instructs. An inverse Fourier transformer generates a plurality of inverse Fourier-transformed symbols by performing inverse Fourier transform on a plurality of key symbols and a plurality of modified Walsh-Hadamard-transformed data symbols. A transmitter transmits a plurality of inverse Fourier-transformed symbols to a channel through at least one antenna.

Abstract: Provided is an identification signal analyzing apparatus and method for compensating power of a channel profile occurring at a conventional identification signal analyzing apparatus by using a power compensation. The identification signal analyzing apparatus includes: an identification signal generator for generating an identification signal identical to a known identification signal inserted by a transmission device; a partial correlator for calculating a correlation value between a received signal including the known identification signal inserted by the transmission device and the identification signal generated by the identification signal generator through a partial correlation; a power compensator for compensating power of the correlation value calculated by the partial correlator; and a channel profile extractor for extracting a channel profile from the correlation value compensated by the power compensator.

Abstract: In a digital broadcasting signal transmission system, a transmission frame includes a frame body and a frame header, and the frame body is divided into a plurality of sub-bands in the frequency domain and is divided into a plurality of symbols in the time domain. The frame header is provided in the former part of the transmission frame and is transmitted with a signal in the time domain. The frame body includes a plurality of services, and the services respectively receive at least one sub-band and at least one symbol. The frame header includes information on the plurality of services, and information on the plurality of services includes information on the sub-band and the symbol to which the services are allocated, information on channel encoding levels of the services, and information on digital modulation levels of the services.

Abstract: Disclosed is a system for transmitting encrypted broadcast signals to different transmitters on a single frequency network (SFN) in a digital broadcasting system. The system for transmitting encrypted broadcast signals on the SFN includes: a main broadcasting system for transmitting encrypted broadcast signals including data streams and transmitter identification information (TII) through a main broadcasting network; a repeating system for amplifying encrypted broadcast signals of the main broadcasting network and transmitting the amplified broadcast signals, or modulating and amplifying streams input by the main broadcasting system through a private line and repeating broadcast signals of the main broadcasting system through a repeating network; and a decrypting key provider for receiving a decrypting key value from the main broadcasting or repeating system and transmitting a user authentication and decrypting key to a charged subscriber terminal through a mobile communication network.

Abstract: In a digital broadcasting signal transmission system, a transmission frame includes a frame body and a frame header, and the frame body is divided into a plurality of sub-bands in the frequency domain and is divided into a plurality of symbols in the time domain. The frame header is provided in the former part of the transmission frame and is transmitted with a signal in the time domain. The frame body includes a plurality of services, and the services respectively receive at least one sub-band and at least one symbol. The frame header includes information on the plurality of services, and information on the plurality of services includes information on the sub-band and the symbol to which the services are allocated, information on channel encoding levels of the services, and information on digital modulation levels of the services.

Abstract: A data transmitting apparatus performs symbol mapping on each of first and second input data to generate a plurality of first and second modulation data symbols, performs inverse fast Fourier transform (IFFT) on the plurality of first and second modulation data symbols to convert the same into first and second real signals of a time domain from a frequency domain, angle-modulates the first and second real signals, and transmits the same to a data receiving apparatus. Thus, a peak-to-average power ratio (PAPR) can be lowered, while the same data transfer amount as that of the general OFDM data transmitting apparatus is maintained.

Abstract: A scalable video decoder and a controlling method thereof are provided. A method of controlling a scalable video decoder includes: determining whether a macro block mode of an upper layer is an interlayer prediction mode when decoding a scalable video; when the macro block mode of the upper layer is determined as the interlayer prediction mode, determining an up-sampling operation is required to thereby either perform texture up-sampling using corresponding macro block information of a lower layer and neighboring pixel information, or perform residual up-sampling using the corresponding macro block information of the lower layer; and decoding the upper layer using the texture up-sampling or the residual up-sampling.

Abstract: Disclosed are data transmission/reception apparatus and method that may be applied to a case where additional data is to be transmitted in a CE-OFDM modulation/demodulation scheme that satisfies an OFDM feature which is robust against multipath fading and simultaneously has a feature that amplitude is constant. Service channel information, modulation parameter information of a physical layer, and the like, may be transmitted by using an additionally secured information channel. If using this, a service search time may be saved, and power of a receiver may be reduced.

Abstract: A data transmitting apparatus generates a plurality of pilot signals to be used for channel estimation by a data receiving apparatus, performs symbol mapping of a plurality of input data signals and a plurality of pilot signal into a plurality of data symbols and a plurality of pilot symbols, converts input symbols in the frequency domain including the plurality of data symbols and the plurality of pilot symbols into a real signal in the time domain, and performs angle modulation of the real signal. The data transmitting apparatus controls the amplitude of the sine component of the angle-modulated real signal by a gain that varies with a control signal and then transmits the real signal.

Abstract: A data transmitting apparatus generates a plurality of modulation data symbols by symbol-mapping a plurality of input data signals, converts the plurality of modulation data symbols to a real signal of a time domain from a frequency domain, performs angle modulation of the signal, and controls and transmits the size of a sine signal of the angle-modulated real signal with a gain varying according to a control signal.

Abstract: A broadcasting signal transmitting device transmits a broadcasting signal including a base layer signal and an enhancement layer signal as well as an additional layer signal relating to the broadcasting signal to a broadcasting signal receiving device. The broadcasting signal receiving device selectively provides the enhancement layer signal and the additional layer signal to the user according to the user's service level. Accordingly, various services are differently provided to the user according to the user level.

Abstract: Provided is a channel estimation apparatus and method using a linear/nonlinear average in a wireless communication system. The present research provides a channel estimation apparatus and method for estimating a channel between a transmitter and a receiver from a pilot-inserted OFDM signal and linearly or nonlinearly averaging the estimating channel, thereby preventing the equalizer performance from being degraded by noise component of the estimated channel and noise amplification caused by deep fading. The channel estimation apparatus includes: a channel estimation unit configured to estimate a channel coefficient of a channel between a transmitter and a receiver from a pilot-inserted carrier signal according to pilot arrangement; and a linear/nonlinear averaging unit configured to linearly or nonlinearly averaging the estimated channel coefficient, thereby preventing an equalizer performance from being degraded by noise component existing in the channel and noise amplification caused by deep fading.

Abstract: Provided are an apparatus and method for compensating a feedback path distortion in a digital broadcasting signal. The apparatus for improving a performance of a pre-equalizer in a transmitter of a digital broadcasting system having a feedback path for adaptively generating a filter coefficient of the pre-equalizer, includes a reference signal generator for generating a reference radio frequency (RF) signal, a feedback path estimator for estimating transmission band characteristic information for the feedback path based on the reference RF signal generated from the reference signal generator, and a feedback path compensator for compensating a demodulated signal transferred through the feedback path based on the estimated transmission band characteristic information from the feedback path estimator and generating a filter coefficient of the pre-equalizer.

Abstract: Provided is a multi-dimensional layered modulation transmitting and receiving apparatus and method for stereoscopic three-dimensional (3D) video data. The transmitting apparatus may convert multi-dimensional data to a plurality of stream data by mapping the multi-dimensional data to a complex number plane, and may transmit the plurality of stream data by mapping the plurality of stream data to dimensions divided based on a time and a space, respectively. The receiving apparatus may determine a signal strength of received signal, a performance, a power mode, may determine a service image corresponding to the signal strength, the performance, the power mode, may determine a dimension corresponding to the service image, and may receive stream data of the determined dimension.

Abstract: An on-channel repeating apparatus and method is provided. The method includes subtracting a replica of a feedback signal from a signal received from a main transmitter or another repeating apparatus; demodulating and equalizing the signal to remove noise, a multipath signal, and the remaining feedback signal from the signal; inserting identification signal having good correlation properties into the signal; modulating the signal; and transmitting the modulated signal.