Abstract: Disclosed herein are an apparatus and method for transmitting and receiving a 4-layer layered-division multiplexing (LDM) signal. An apparatus for transmitting a 4-layer layered-division multiplexing signal includes a layered-division multiplexing modulation unit for generating a 3-layer layered-division multiplexing signal by performing layered-division multiplexing modulation on three layer signals and generating a 4-layer layered-division multiplexing signal by inserting a Pseudo-random Noise (PN) sequence into the 3-layer layered-division multiplexing signal, a pilot insertion unit for inserting a pilot into the 4-layer layered-division multiplexing signal, and a transmission unit for transmitting the 4-layer layered-division multiplexing signal.

Abstract: Disclosed herein are an apparatus and method for transmitting and receiving a 4-layer layered-division multiplexing (LDM) signal. An apparatus for transmitting a 4-layer layered-division multiplexing signal includes a layered-division multiplexing modulation unit for generating a 3-layer layered-division multiplexing signal by performing layered-division multiplexing modulation on three layer signals and generating a 4-layer layered-division multiplexing signal by inserting a Pseudo-random Noise (PN) sequence into the 3-layer layered-division multiplexing signal, a pilot insertion unit for inserting a pilot into the 4-layer layered-division multiplexing signal, and a transmission unit for transmitting the 4-layer layered-division multiplexing signal.

Abstract: Disclosed herein is a demodulation method of a Layer-Division Multiplexing (LDM) system. The demodulation method may include receiving an LDM modulation signal, restoring a first-layer signal from the LDM modulation signal and remodulating the first-layer signal, restoring and remodulating a second-layer signal by performing cancellation of the amplitude component of the first-layer signal from the LDM modulation signal using signaling information independently of restoration and remodulation of the first-layer signal, and restoring a third-layer signal using the first-layer signal, the second-layer signal, and the LDM modulation signal.

Abstract: Disclosed herein is a demodulation method of a Layer-Division Multiplexing (LDM) system. The demodulation method may include receiving an LDM modulation signal, restoring a first-layer signal from the LDM modulation signal and remodulating the first-layer signal, restoring and remodulating a second-layer signal by performing cancellation of the amplitude component of the first-layer signal from the LDM modulation signal using signaling information independently of restoration and remodulation of the first-layer signal, and restoring a third-layer signal using the first-layer signal, the second-layer signal, and the LDM modulation signal.

Abstract: Disclosed are a roll-off period detection method, a symbol starting point detection method, a fractional frequency offset estimating method, and an OFDM downstream system using the same. A method of detecting a roll-off period in an OFDM downstream system according to an embodiment of the present disclosure may include: generating a temporary roll-off period by applying a windowing function to a signal having a preset length; and detecting a roll-off period based on any one of a cross correlation and a sum of differences between a detection target signal included in a range of two OFDM symbol signals based on a detection starting point, and the temporary roll-off period.

Abstract: Disclosed are a method for acquiring synchronization in a cable network, and a physical (PHY) transmitter and PHY receiver. The method for acquiring synchronization in a cable network according to an embodiment includes receiving, by a PHY receiver, a signal from a PHY transmitter, and acquiring, by the PHY receiver, channel synchronization when a symbol in which a channel preamble exists is detected from the received signal and a position of a frequency in which a channel subcarrier exists is detected from the detected symbol by performing a cross correlation operation on the received signal and the channel preamble.

Abstract: A method of estimating an integer frequency offset and compensating for the integer frequency offset by an estimated error is provided. A frequency offset estimation method may include receiving a reception signal including PLC data and a physical layer link channel (PLC) preamble, detecting first position information on a position of a subcarrier of the PLC preamble in a frequency axis from the reception signal through a cross-correlation between the PLC preamble and the reception signal, detecting second position information on the position of the subcarrier of the PLC preamble defined in a transmission end by restoring the PLC data, and calculating a frequency offset by comparing the first position information with the second position information.

Abstract: Disclosed are a roll-off period detection method, a symbol starting point detection method, a fractional frequency offset estimating method, and an OFDM downstream system using the same. A method of detecting a roll-off period in an OFDM downstream system according to an embodiment of the present disclosure may include: generating a temporary roll-off period by applying a windowing function to a signal having a preset length; and detecting a roll-off period based on any one of a cross correlation and a sum of differences between a detection target signal included in a range of two OFDM symbol signals based on a detection starting point, and the temporary roll-off period.

Abstract: A method of estimating an integer frequency offset and compensating for the integer frequency offset by an estimated error is provided. A frequency offset estimation method may include receiving a reception signal including PLC data and a physical layer link channel (PLC) preamble, detecting first position information on a position of a subcarrier of the PLC preamble in a frequency axis from the reception signal through a cross-correlation between the PLC preamble and the reception signal, detecting second position information on the position of the subcarrier of the PLC preamble defined in a transmission end by restoring the PLC data, and calculating a frequency offset by comparing the first position information with the second position information.

Abstract: Disclosed are a method for acquiring synchronization in a cable network, and a physical (PHY) transmitter and PHY receiver. The method for acquiring synchronization in a cable network according to an embodiment includes receiving, by a PHY receiver, a signal from a PHY transmitter, and acquiring, by the PHY receiver, channel synchronization when a symbol in which a channel preamble exists is detected from the received signal and a position of a frequency in which a channel subcarrier exists is detected from the detected symbol by performing a cross correlation operation on the received signal and the channel preamble.

Abstract: Disclosed is a an apparatus for reducing a reducing a peak to average power ratio (PAPR) for layer division multiplexing (LDM) in an orthogonal frequency division multiplexing (OFDM) system, the apparatus may include a peak remover configured to detect a peak power value of a subcarrier signal that is input and generate a peak removal signal that decreases the detected peak power value, and a processor configured to perform constellation remapping on a first signal generated by combining the subcarrier signal and the peak removal signal and then generate a second signal into which additional data is inserted.

Abstract: An apparatus and a method of channel estimation and equalization based on pilot signals, which acquire a channel estimation vector and effectively perform channel equalization by using scattered pilots and continuous pilots in a communication system to which an OFDM symbol is applied, such as a DOCSIS 3.1 Down stream PHY system using multiple carriers.

Abstract: An image processing apparatus using a smart glass is provided, the image processing apparatus including an extractor to extract a first target to be observed by a user from a first image received from the smart glass and generate a second image using the extracted first target, an information collector to collect information related to the first target, and an image generator to reconstruct a third image using at least one of the second image and the information related to the first target, based on user settings.

Abstract: Provided is a Multiple Input Multiple Output (MIMO) transmission method in a digital broadcasting system. The method includes generating a plurality of first modulation symbols by modulating first information bits; generating a plurality of second modulation symbols by modulating second information bits; generating a plurality of first pre-coded symbols and a plurality of second pre-coded symbols by pre-coding the plurality of first modulation symbols and the plurality of second modulation symbols; and allocating the plurality of first pre-coded symbols and the plurality of second pre-coded symbols staggeringly through a first antenna and a second antenna and transmitting them.

Abstract: There is disclosed a method of synchronizing a first image and a second image forming multiple images in broadcasting service based on the multiple images. The method includes receiving a stream regarding the first stream and a stream regarding the second stream through a plurality of channels, obtaining the first image and the second image by decoding the stream regarding the first stream and the stream regarding the second stream and obtaining a base Program Clock Reference (PCR) descriptor in at least one of the stream regarding the first stream and the stream regarding the second stream, selecting a base stream based on the base PCR descriptor and determining a base PCR based on the base PCR descriptor, and synchronizing the first image and the second image based on the base PCR.

Abstract: An image processing apparatus using a smart glass is provided, the image processing apparatus including an extractor to extract a first target to be observed by a user from a first image received from the smart glass and generate a second image using the extracted first target, an information collector to collect information related to the first target, and an image generator to reconstruct a third image using at least one of the second image and the information related to the first target, based on user settings.

Abstract: Provided is a Multiple Input Multiple Output (MIMO) transmission method in a digital broadcasting system. The method includes generating a plurality of first modulation symbols by modulating first information bits; generating a plurality of second modulation symbols by modulating second information bits; generating a plurality of first pre-coded symbols and a plurality of second pre-coded symbols by pre-coding the plurality of first modulation symbols and the plurality of second modulation symbols; and allocating the plurality of first pre-coded symbols and the plurality of second pre-coded symbols staggeringly through a first antenna and a second antenna and transmitting them.

Abstract: Provided are an apparatus and method for selecting an optimal signal using auxiliary equalization in a diversity receiver. The optimal signal selecting apparatus includes: a plurality of sync recovery units for extracting sync information from baseband signals, which are candidate signals, except a baseband signal selected as a current optimal signal a plurality of auxiliary equalizers for channel-equalizing the candidate signals based on the extracted sync information; a plurality of SNR measuring units for measuring signal-to-noise ratios (SNRs) of the candidate signals inputted to the auxiliary equalizers and the candidates signals equalized in the auxiliary equalizers; and an optimal signal selector for selecting an optimal candidate signal from the candidate signals by using the extracted sync information and the measured SNRs, and replacing the optimal signal with the optimal candidate signal when reception quality of the current optimal signal is poor.

Abstract: A method for providing social broadcasting services by a broadcasting station is registered. The method for providing social broadcasting services includes receiving from a social network server like function related information triggering transmission of an interest indicator indicating that a user of a user equipment has an interest in broadcasting programs provided by a content provider; and transmitting both of the broadcasting programs and additional data including the like function related information to the user equipment. By the configuration, the exemplary embodiments of the present invention can share the personal's opinion and thoughts and the additional data associated with the corresponding programs through the social circle while the user viewing the broadcasting programs in real time during the movement.

Abstract: Provided are a beam combining and hybrid beam selection method that can improve digital broadcasting reception performance by combining more than two beam output signals (beam combination type) instead of simply selecting one of beam output signals (beam selection type), or even selecting an optimal method between the beam selection type and the beam combination type, and a digital broadcasting receiving apparatus using the same.