Abstract: Proposed is a method in which a server presents content through a chat room. The method may include acquiring information about a keyword or theme of the content, information about a condition for presenting the content, and information about the chat room, wherein the chat room is related to the keyword or theme and a plurality of users are able to participate in the chat room. The method may also include providing the chat room to a user terminal in association with the information about the keyword or theme of the content. The method may further include searching for the content in a content pool based on the keyword or theme, and when the condition for presenting the content is satisfied, presenting at least some items of the searched content to the user terminal through the chat room.

Abstract: A wireless receiving apparatus includes a plurality of wireless receiving modules that receive a plurality of sub-streams constituting a video frame from a wireless transmitting apparatus and a data processing module that determine whether an error occurs in each of the plurality of sub-streams, in response to determining that an error does not occur in any of the plurality of sub-streams, merges the plurality of sub-streams to generate the video frame, transmits the video frame to a display electrically connected to the wireless receiving apparatus, and in response to determining that an error occurs in at least one of the plurality of sub-streams, transmits an immediately-preceding video frame to the display.

Abstract: A wireless receiving apparatus includes a plurality of wireless receiving modules that receive a plurality of sub-streams constituting a video frame from a wireless transmitting apparatus and a data processing module that determine whether an error occurs in each of the plurality of sub-streams, in response to determining that an error does not occur in any of the plurality of sub-streams, merges the plurality of sub-streams to generate the video frame, transmits the video frame to a display electrically connected to the wireless receiving apparatus, and in response to determining that an error occurs in at least one of the plurality of sub-streams, transmits an immediately-preceding video frame to the display.

Abstract: A method and an apparatus for mapping a quadrature amplitude modulation (QAM) symbol. The QAM symbol mapping apparatus includes a frequency checker, which checks frequencies of sub-carriers in an orthogonal frequency division multiplexing (OFDM) symbol; and a data categorizer, which maps data coded for error correction and uncoded data to the sub-carriers based on the checked frequencies, wherein the data categorizer maps a combination of the coded data and the uncoded data with respect to sub-carriers having frequencies lower than a reference frequency.

Abstract: A method and an apparatus for mapping a quadrature amplitude modulation (QAM) symbol. The QAM symbol mapping apparatus includes a frequency checker, which checks frequencies of sub-carriers in an orthogonal frequency division multiplexing (OFDM) symbol; and a data categorizer, which maps data coded for error correction and uncoded data to the sub-carriers based on the checked frequencies, wherein the data categorizer maps a combination of the coded data and the uncoded data with respect to sub-carriers having frequencies lower than a reference frequency.