Electronics and Telecommunications Research Institute

Lg Electronics Inc.

Dong Joon Choi

Nam Ho Hur

Joon Young Jung

Namho Hur

Je Won Lee

Myeong Kyoo Yang

Joung Sea Park

Soo In Lee

Jae Ho Lee

Han Seung Koo

Jae Hwui Bae

Jin Hyuk Song

Sang Jung Ra

Sung Ik Park

O Hyung Kwon

Sang-Jung Ra

Young Kwon Hahm

Yang Su Kim

Jae-Young Lee

Heung Mook Kim

Hoi Yoon Jung

Soon Choul Kim

Jae-Ho Lee

Hyun-Jeong Yim

Ho Sub Lee

Eun Hee Hyun

Ho-Sook Lee

Ho Sook Lee

Ye Yong Kim

Hye Ju Oh

Woongshik You

Kwan Woong Ryu

An operation method of a terminal in a communication system may comprise: receiving downlink control information (DCI) for scheduling uplink transmission from a base station; identifying a communication node initiating a channel occupancy time associated with the uplink transmission based on a channel access parameter included in the DCI; and performing the uplink transmission scheduled by the DCI within the channel occupancy time initiated by the communication node, wherein the communication node is the terminal or the base station.

Method and apparatus for channel access in communication system supporting unlicensed band

According to an embodiment of the present disclosure, there is provided a method and apparatus for transmitting/receiving a digital broadcast. The method for transmitting a digital broadcast, the method comprising: configuring AV data; configuring broadcast data; configuring application signaling information (ASI) by considering at least one of the AV data and the broadcast data or combination thereof; configuring an MPEG-based transport stream by multiplexing the AV data, the broadcast data and the ASI; and transmitting the MPEG-based transport stream, wherein the ASI includes data for driving an application executed by a broadcast receiver.

Method and apparatus for transmitting/receiving digital broadcast

An adaptive multi-view streaming processing method and apparatus for a multi-view stream is disclosed. Specifically, disclosed herein is a method and apparatus for adaptively processing or transmitting adaptive streaming by reflecting network states and changes in transmission environments in a multi-view streaming service environment where several or more multiple videos are simultaneously transmitted at an arbitrary moment. An adaptive streaming processing method for a multi-view stream may comprise selecting and downloading an i-th segment of a main view stream with a first quality level, inferring a size of an i-th segment of downloadable neighboring view streams based on a download time and transfer rate of the i-th segment of the main view stream, and selecting a second quality level corresponding to the inferred size of the i-th segment of the neighboring view streams and downloading the i-th segment of the neighboring view streams based on the selected second quality level.

Method and apparatus for processing adaptive multi-view streaming

Disclosed are an apparatus and method for providing an offloading service. A method of providing an offloading service according to an example embodiment includes streaming, to a user terminal including a cellular network receiver and a broadcast network receiver, media content data through a cellular network, transmitting, to the user terminal, an offloading service providing signal for activating the broadcast network receiver of the user terminal through the cellular network, transmitting, to the user terminal, a broadcast signal including connection information of a broadcast network to which the user terminal is to be connected so as to receive the media content data, through the cellular network, and broadcasting the media content data through the broadcast network.

Apparatus and method for providing offloading service

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.

Roll-off period detecting method, symbol starting point detecting method, fractional frequency offset estimating method, and OFDM downstream system thereof

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.

Apparatus and method for IP based transmission of upstream RF signal in cable broadcasting network

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.

Method for acquiring synchronization, and PHY transmitter and PHY receiver for cable network

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.

Frequency offset estimation and compensation method

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.

Apparatus and method for soft-decision demodulating in non-square quadrature amplitude modulation

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.

Apparatus and method for transmitting and receiving broadcasting

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. The multiplexing apparatus includes a packet restoration unit for detecting first field information for restoration and second field information for synchronization from each of pre-headers included in (N+1) output packets received through at least two channels and generating N restoration packets using the first field information and an output synchronization unit for performing output timing synchronization between the N restoration packets using the second field information.

Demultiplexing apparatus, multiplexing apparatus, and multi-channel transmission and reception method using the same

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.

Method and system for transmitting broadcast and data stream and method and apparatus for converting broadcast and data stream in HFC-based cable network

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.

Method and apparatus for compensating for variable symbol timing using cyclic prefix in non-synchronized OFDM system

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.

Method for transmitting data using variable guard interval and apparatus thereof

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.

Growing community of inventors

Daejeon, South Korea

Dong Joon Choi