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 method for transmitting moving picture experts group (MPEG)-2 transport stream (TS) broadcasting data for a broadcasting service based on a physical layer transmission standard defined in a Data over Cable Service Interface Specification (DOCSIS) 3.1. The apparatus includes a converter configured to receive an input of broadcasting data including a plurality of MPEG-2 TS packets and to convert the broadcasting data to a first file with a forward error correction (FEC) codeword structure, and an encoder configured to encode the first file.

Abstract: Provided are an apparatus and method for broadcasting-communications convergence in a hybrid fiber coax (HFC) network. The apparatus includes an optical connector configured to receive broadcast data and communication data from a cable broadcasting station through an optical cable, a channel switch configured to receive the broadcast data from the optical connector and select a piece of broadcast data to be transmitted to a subscriber from among pieces of the broadcast data, and a convergence processor configured to receive the communication data from the optical io connector, receive the selected piece of broadcast data from the channel switch, generate broadcasting-communications convergence data by multiplexing the received communication data and the selected piece of broadcast data, and transmit the broadcasting-communications convergence data.

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: Disclosed are an apparatus and a method for soft-decision demodulating in non-square quadrature amplitude modulation. The apparatus includes: a signal receiving unit receiving a quadrature amplitude modulation (QAM) modulated signal at an m modulation degree at a transmitting side; a soft-decision bit calculating unit determining a soft-decision bit value by calculating log likelihood ratios (LLRs) for m bits of the received QAM modulated signal; and a signal decoding unit restoring the received QAM modulated signal based on the determined soft-decision bit value, in which the soft-decision bit calculating unit defines a log likelihood ratio calculation equation by approximating soft-decision boundary points of constellation points for m bits of non-square QAM having odd bits, respectively.

Abstract: An apparatus and a method for converting an upstream radio frequency (RF) signal to a digital signal and transmitting the digital signal via an Internet protocol (IP) packet based on an optical network in a cable broadcasting network is provided. The apparatus for transmitting an upstream RF signal includes a detector configured to detect an upstream RF signal, and a transmitter configured to digitize the detected upstream RF signal and transmit the digitized RF signal to a headend via an IP packet.

Abstract: A broadcasting transmitting apparatus configures one broadcasting channel as at least two video streams, generates a program map table (PMT) representing configuration information of a stream included within the broadcasting channel, sets a program type provided through the corresponding broadcasting channel within the PMT, multiplexes the at least two video streams and signaling information, and transmits the multiplexed two video streams and signaling information through a broadcasting network.

Abstract: Provided is a channel switching method and channel reception method to enhance spectrum use efficiency and a channel switching apparatus and channel reception apparatus using the same. The channel switching method may include extracting, based on received information associated with a virtual channel currently viewed by a user, broadcasting data on a corresponding virtual channel in a physical channel, determining communication data to be added to an idle frequency band in the physical channel including the extracted broadcasting data, and transmitting a transmission data stream generated based on communication data and broadcasting data included in the physical channel, wherein the physical channel comprises broadcasting data on a plurality of virtual channels and uses a predetermined frequency band.

Abstract: A demultiplexing apparatus, a multiplexing apparatus, and a multi-channel transmission and reception method using the same are provided. The demultiplexing apparatus includes a broadcasting data reception unit for separating a broadcasting data stream into N input packets, an output packet generation unit for generating (N+1) output packets by connecting a pre-header, including a field for multi-channel transmission, with each of the N input packets, and a packet distribution unit for distributing the (N+1) output packets over at least two channels.

Abstract: A method for transmitting broadcast and data streams in an HFC-based cable network includes a first transmission step of a broadcast transmission apparatus sending broadcast and data service streams in an IP-based stream or RF signal form through an optical section up to a cell node that is a contact point between the optical section and a cable section of a cable network and a second transmission step of the cell node converting the broadcast and data service streams into one of RF signal, IP-based stream, and RF/IP convergence service stream forms depending on a service type of a subscriber terminal and sending the converted broadcast and data service streams to the subscriber terminal through the cable section.

Abstract: Disclosed are a method and apparatus for estimating symbol timing in a non-synchronized OFDM system. The present invention includes synchronizing a frame of a received signal, estimating the symbol timing of each symbol of the frame based on the synchronization, compensating for the symbol timing using a phase difference attributable to a Symbol Timing Offset (STO), variably changing within a Cyclic Prefix (CP) interval due to the frequency offset of a sampling clock and thermal noise, and performing channel equalization using a preamble based on output including corrected phase rotation.

Abstract: A method and apparatus for providing a mobile broadcasting service over a cable broadcasting network are provided. A mobile broadcast signal and a cable broadcast signal are transmitted over the cable broadcast network. The cable broadcast signal and the mobile broadcast signal are filtered to pass the mobile broadcast signal, and the passed mobile broadcast signal is sent to a mobile broadcast terminal.

Abstract: In an orthogonal frequency division multiplexing (OFDM) wireless communication system, when path delay information is received from a reception apparatus through a return path after data transmission, a length of a cyclic prefix included in a transmitted signal is adjusted on the basis of a delay value included in the path delay information.

Abstract: In an orthogonal frequency division multiplexing (OFDM) wireless communication system, when path delay information is received from a reception apparatus through a return path after data transmission, a length of a cyclic prefix included in a transmitted signal is adjusted on the basis of a delay value included in the path delay information.

Abstract: A broadcasting transmitting apparatus splits a piece of broadcast content into an audio signal and a video signal, encodes the audio signal to generate an audio bit string, encodes the video signal to generate a video bit string, multiplexes the audio bit string and the video bit string, and modulates the multiplexed bit strings into a symbol. The encoded audio bit string is allocated to some bits of the symbol, and the encoded audio bit string is allocated to the remaining bits of the symbol.

Abstract: An apparatus for combining a broadcasting channel may include a channel detector to detect a vacant Radio Frequency (RF) broadcasting channel used by a photoelectric converter that converts a first broadcast program as an optical signal to a first RF signal, a broadcast receiving interface to receive at least one second broadcast program, a broadcast modulator to generate a second RF signal by modulating the second broadcast program using the vacant RF broadcasting channel, and a channel combiner to combine a broadcasting channel used for the first RF signal and the vacant RF broadcasting channel.

Abstract: A broadcasting transmitting apparatus configures one broadcasting channel as at least two video streams, generates a program map table (PMT) representing configuration information of a stream included within the broadcasting channel, sets a program type provided through the corresponding broadcasting channel within the PMT, multiplexes the at least two video streams and signaling information, and transmits the multiplexed two video streams and signaling information through a broadcasting network.

Abstract: A method for receiving contents using a mobile terminal according to the present invention is provided. The method includes generating a security channel connected to system being in charge of a service and content protection (SCP) client through an agent downloaded and installed in a mobile terminal; downloading and installing one or multiple SCP client software of different kind from the system through the security channel generated by the agent; and playing back the service or content provided in protected state by a content provider among the one or multiple SCP client software of different kind by driving the decodable SCP client software.

Abstract: Disclosed are a network protocol for contents protection in a digital cable broadcasting service and a conditional access system using the protocol. A method for renewing conditional access client software (CACS) by a conditional access module in a renewable conditional access system (RCAS) may include: receiving an RCAS announcement message from a headend; transmitting to the headend a key registration request message for requesting an authorization key when the RCAS announcement message is authenticated; receiving a key registration response message including the authorization key from the headend; and generating security factors based on the authorization key and renewing the CACS by using the security factors.