Abstract: An apparatus and method for transmitting a reference signal in an Orthogonal Frequency Division Multiple Access (OFDMA) communication system in which a total frequency band is divided into a plurality of subcarrier bands. A time division multiplexer performs time division multiplexing such that the reference signal is transmitted for a first duration in a predetermined number of subcarrier bands from among the plurality of the subcarrier bands, and a signal other than the reference signal is transmitted for a second duration other than the first duration. A transmitter transmits the time-division multiplexed subcarrier band signals.

Abstract: A mobile communication system and method utilizing Orthogonal Frequency Division Multiplexing (OFDM) receives channel quality information (CQIs) for subcarriers through which reference signals are transmitted and subcarriers through which data signals are transmitted, in subbands, each including a predetermined number of subcarriers among a plurality of the subcarriers. The CQIs are received from respective receivers. Resources are dynamically assigned to the respective receivers according to the feedback CQIs, thereby enabling dynamic resource assignment with minimized signaling overhead.

Abstract: An apparatus and method for switching between an AMC mode and a diversity mode adaptively according to a channel environment in a broadband wireless communication system are provided. According to the present invention, a transmitter (a base station) determines a transmission mode according to frequency-domain and time-domain channel measurement information received from a receiver (a mobile station). If the transmission mode is the AMC mode, the transmitter selects a coding and modulation scheme according to a frequency-domain CQI received from the receiver. If the transmission mode is a diversity mode, the transmitter selects a predetermined coding and modulation scheme.

Abstract: A transmitting and receiving apparatus and method for optimizing performance of an adaptive modulation and coding (AMC) in a multiple input and multiple output antenna (MIMO) communication system. When the AMC is applied to the MIMO system, the optimal scheme is different depending on the MIMO channel situation, the maximum transmission power, and the maximum modulation order. The transmitting apparatus includes an ordering selector that selects a successive interference cancellation (SIC) scheme in order to obtain a maximum MIMO-AMC performance, and the receiving apparatus includes a channel quality information (CQI) generator corresponding to the SIC scheme selected at the transmitting apparatus.

Abstract: Provided are a method and apparatus for generating a playlist of media content and a method and apparatus for playing media content. The method of generating a playlist of media content includes providing a user interface for setting a playlist while media content is being played and generating a playlist of media content to be played according to playlist settings set through the user interface.

Abstract: An apparatus and method for generating an octal code for identifying cells in a mobile communication system. In the octal code generating apparatus, a binary code generator generates a binary code with a predetermined minimum Hamming distance. A column permutator permutes the order of columns of the binary code in a predetermined interleaving method. A 3-bit combiner generates a plurality of codewords using the column-permuted binary code as a generator matrix and groups the bits of each of the codewords by threes. An octal code generator converts the 3-bit grouped binary codewords to octal code sequences.

Abstract: Disclosed is a method for transmitting/receiving data by use of feedback information in a closed loop multi input multi output (MIMO) mobile communication system. The method includes the steps of feeding back transmission eigenvector selection information determined through a singular value decomposition (SVD) of a channel matrix and transmitting the transmission eigenvector selection information to a transmitter; and receiving the feedback transmission eigenvector selection information, selecting transmission data according to the received transmission eigenvector selection information, mapping the selected transmission data to at least one transmission antenna, and transmitting the transmission data to a receiver.

Abstract: An apparatus and method for transmitting/receiving a pilot pattern set to distinguish a base station in an FDM communication system. The method divides a total frequency bandwidth into at least two sub-bandwidths including a plurality of sub-carriers in an OFDMA (Orthogonal Frequency Division Multiple Access) mobile communication system, configures a single frame cell (FC) using one sub-bandwidth from among the sub-bandwidths and a plurality of OFDM (Orthogonal Frequency Division Multiplexing) symbol intervals, and assigns a pilot signal to a time-frequency cell comprised of at least one OFDM symbol and at least one sub-carrier within the FC. The method includes the steps of spreading a pilot signal and a data signal using different orthogonal codes, synthesizing the spread pilot and data signals, and performing a CDM (Code Division Multiplexing) process; and mapping the CDM-processed pilot and data signals to a predetermined time-frequency cell in the FC.

Abstract: A method and apparatus for synchronizing feed information are provided. A podcasting client includes a synchronization-processing unit which synchronizes first feed information acquired from a connected device with pre-stored second feed information, and a communication interface which transmits feed information of content that is podcast based on the synchronized feed information to the connected device.

Abstract: A transmitter for a mobile communication system based on an OFDM scheme and a method for controlling the same. The transmitter can implement a characteristic of a multiple access scheme based on an OFDM scheme, a characteristic of a CDMA scheme, and a characteristic of a frequency hopping scheme which has very strong resistance to the frequency selective fading.

Abstract: In a mobile communication system including a transmitter and a receiver, an LDPC code is generated by encoding received information data such that a fifth partial matrix obtained by combining a second partial matrix having even-numbered columns of a first partial matrix corresponding to the information data with a fourth partial matrix having odd-numbered columns of a third partial matrix corresponding to a parity, and an eighth partial matrix obtained by combining a sixth partial matrix having odd-numbered columns of the first partial matrix with a seventh partial matrix having even-numbered columns of the third partial matrix correspond to a ninth partial matrix obtained by exclusive-ORing the first partial matrix and the third partial matrix and a parity check matrix having a predetermined rank in a binary field. A space-time LDPC code is generated by spatial-mapping the LDPC code according to a predetermined spatial mapping scheme.

Abstract: A trellis encoding device includes a plurality of trellis encoders to perform trellis-encoding of a transport stream into which a supplementary reference signal (SRS) has been inserted, and performs a memory reset in a region that precedes an SRS; and a parity compensation unit to compensate for parities of the transport stream in accordance with values stored in memories included in the trellis encoders. The plurality of trellis encoders may be implemented in diverse types. The trellis encoding device can perform a memory reset selectively using the stored value of the memory and the inverted value thereof, or selectively using the stored value of the memory and a fixed value. By properly resetting the memory in processing the transport stream into which the SRS has been inserted, DC offset can be reduced.

Abstract: Disclosed is a signal constructing method according to an adaptive packet format in a MIMO-WLAN (Multi-input multi-output Wireless LAN) system. A method is used to construct a plurality of signals in a MIMO-WLAN, with transmitting a data packet as a plurality of signals via a plurality of antennas. The method includes the steps of: constructing a data packet to include a preamble for packet transmission, an additional information region for data packet transmission in MIMO-WLAN system, and a service data unit; distributing data of the preamble to at least one of the plurality of signals; distributing data of the additional information region to at least one of the plurality of signals; and distributing data of the service data unit to at least one of the plurality of signals. The method is compatible with existing wireless LAN technology standard mode, and also provides high-speed data transmission rate.

Abstract: A method and apparatus for managing contents distributed on a home network are provided. The distributed content management apparatus includes: a content information database processor which aggregates information regarding contents stored in at least one content reproducing apparatus and creates or updates an integrated content information database; and a synchronization processor which performs content synchronization to synchronize the information regarding the contents stored in the content reproducing apparatus with contents defined in a synchronization list set by a user, using the integrated content information database. The apparatus further includes a content change information receiver which receives changed contents from the content reproducing apparatus if contents information stored in a content reproducing apparatus changes; and a content information database updating unit which updates the integrated content information database to reflect the changed contents.

Abstract: Provided are a synchronization identifier generating method for synchronizing digital contents and an apparatus for the same. The synchronization identifier generating method includes setting a sampling level that indicates a frequency of sampling digital contents; sampling the digital contents on the basis of the set sampling level; generating a first message digest on the basis of data sampled during the sampling the digital contents; and generating a synchronization identifier including the set sampling level and the first message digest.

Abstract: A base station having at least one reception antenna generates a reception beam using a previous reception beam weight and a despread signal of a current reception signal, calculates an error value indicating a difference between the current reception signal and a desired reception signal, and calculates a current reception beam weight using the previous reception beam weight, the despread signal and the error value. The base station generates a reception beam weight step value using the error value and an output signal, calculates a difference between the previous reception beam weight and a product of the reception beam weight step value, the despread signal, and a conjugate value of the error value, as the current reception beam weight, and selects the reception beam weight step value such that the current reception beam weight becomes the optimal reception beam.

Abstract: A subcarrier assignment apparatus and a subcarrier assignment method, in which each of a plurality of Base Stations (BSs) constituting an Orthogonal Frequency Division Multiple Access (OFDMA) communication system provides services in the capacity of a serving BS to Mobile Stations (MSs). Channel quality information for the respective MSs are fed-back from the respective BSs. Subcarriers are assigned to the respective MSs according to a corresponding scheduling scheme in consideration of the channel quality information for the respective MSs, which are fed-back from the respective BSs, and then BSs which manage the subcarriers assigned to the respective MSs according to the corresponding scheduling scheme are selected. These operations provide site diversity to each of the MSs, and thus system capacity is maximized.

Abstract: A method and apparatus for synchronizing multimedia content with a client device which supports a multi-server environment are provided. The server includes a synchronization policy management unit which acquires a synchronization policy; a synchronization information collector which collects log information of a previously performed synchronization and of a change occurring after the previously performed synchronization; a synchronization processor which performs synchronization in accordance with the collected log information; a change log management unit which stores a result of the synchronization; an interface unit which transmits the log information; and a storage unit which stores the multimedia content and the meta data of the multimedia content.

Abstract: Provided are a method and apparatus for publishing content through a blog. A publisher terminal publishes content and metadata of the content to a blog and transmits a rich site summary (RSS) including information on the published content from a web server for managing the blog to a RSS client and a publisher terminal. Thus, the content and the metadata can be shared through the blog, and metadata of local content of a publisher and the RSS client and metadata of content of the web server for managing the blog can be synchronized.

Abstract: Disclosed are a pilot tone generation apparatus and a pilot tone generation method for improving channel estimation performance in an OFDMA/CDM communication system. In a pilot tone generation method for channel estimation in a broadband wireless access communication system, if given data symbols and a pilot symbol are input, the input data symbols are code-division multiplexed. A pilot symbol value for generating a sub-carrier of a specific position into the pilot tone is produced and spread, correspondingly to a code-division multiplexed result value of the data symbols Also, a spreading value for the pilot symbol value and the resulting code-division multiplexed value of the data symbols are added up, and the pilot tone is generated at a given position on a frequency axis, which position is predetermined through a result of the adding up.