Abstract:
Provided is an apparatus and method for transmitting and receiving data using multiple paths in a wireless communication system using a distributed Media Access Control (MAC). More particularly, provided is an apparatus and method for transmitting and receiving data that may select a path with a better channel status from multiple paths that include a direct path using a Line of Sight (LOS) and a relay path passing through a relay apparatus, in a wireless communication system that may transmit data via the LOS using a distributed MAC and a directional antenna.
Abstract:
Provided is a method and apparatus for setting a detour path in a wideband high frequency wireless system using a centralized Media Access Control (MAC) protocol. Here, in a wireless system using the centralized MAC protocol where a time synchronization and a band allocation may be performed by a single central control unit, when a signal blockage occurs while a data communication is being performed via a direct path between a source device and a destination device, the detour path may be quickly provided.
Abstract:
A control apparatus for use in wireless communications includes an antenna unit having antennas, the number of the antennas being equal to a maximum allowable number of connections in a specific frequency band; and a controller for receiving a connection request signal from each terminal attempting to connect to the control apparatus via the antenna unit, and transmitting and receiving a data signal to and from each terminal connected to the control apparatus by using a multiple-input-multiple-output scheme. The controller transmit and receive the data signal to and from each terminal connected to the control apparatus by obtaining a signal value of each antenna based on a predicted channel matrix and the number and types of terminals connected to the control apparatus via the antenna and separating the data signal for each terminal from the signal value according to the multiple-input-multiple-output scheme.
Abstract:
Provided is a lossless/near-lossless image compression apparatus and method. The lossless/near-lossless image compression method may include calculating a predicted value by predicting a pixel of a current location based on adjacent pixels, calculating an error that is a difference between the predicted value and a pixel value, and modulating the error to output the modulated error, encoding the modulated error, and controlling a tolerance based on a slice unit to enable a number of encoded bits to be the same as a target number of encoded bits. The tolerance may be set to be gradually increased or to be decreased to prevent a rapid change in the tolerance.
Abstract:
An adaptive modulation apparatus and method using a multiple antenna selection scheme are provided. The adaptive modulation method using the multiple antenna scheme includes: selecting one transmit antenna from a plurality of transmit antennas; determining a target transmission rate of the selected transmit antenna to transmit the determined target transmission rate to a multiple antenna reception apparatus; receiving, from the multiple antenna reception apparatus, feedback information including information regarding whether to accept the target transmission rate; and transmitting data to the multiple antenna reception apparatus using the received feedback information.
Abstract:
Disclosed are a data transceiver and a method thereof in a wireless communication system, and particularly, is a data transceiver and method thereof using multiple routes in the wireless communication system. The data transmitting/receiving method using the multiple routes in the wireless communication system includes setting a direct route to a corresponding station and a relay route to a relay device, selecting one route from among the direct route and relay route, and transmitting/receiving data through the selected route.
Abstract:
An Unequal Error Protection (UEP) transmission apparatus comprises a bit separator unit configured to, when video data are received, separate pixels of the video data into Most Significant Bits (MSBs) and Least Significant Bits (LSBs) according to a degree of importance on a pixel-component basis; a header generation unit configured to create an MSB sub-frame and a LSB sub-frame based on the respective MSBs and LSBs and create an MSB Medium Access Control (MAC) sub-frame and a LSB MAC sub-frame to which respective headers are added; and a channel coding unit configured to create a channel-encoded MSB data and a channel-encoded LSB data by performing error correction encodings corresponding to the respective MSB MAC sub-frame and LSB MAC sub-frame and add padding bits, corresponding to the respective channel-encoded MSB data and channel-encoded LSB data, to the channel-encoded MSB data and channel-encoded LSB data.
Abstract:
Provided are a transmission/receiving apparatus and method of switching a transmission antenna in a Transmission Switched Diversity (TSD) system. The transmission apparatus includes an announcement command frame reading unit to verify a TSD Information Element (IE) included in an announcement command frame when receiving the announcement command frame from a receiving apparatus, and to verify whether to request a switching of the transmission antenna, an antenna switching unit to select an antenna, not being selected from a plurality of antennas, as a transmission antenna when the announcement command frame requests the switching of the transmission antenna, and to switch a currently used antenna into the selected transmission antenna, and an announcement command frame generation unit to convert transmission antenna information included in the TSD IE into the selected transmission antenna, and to generate a response announcement command frame including the converted TSD IE and transmit to the receiving apparatus.
Abstract:
A data transceiving apparatus and method in a centralized MAC-based wireless communication system are provided. The data transceiving method of a centralized MAC-based device may include: setting a direct path to a device and a relay path to a piconet coordinator (PNC); selecting any one of the direct path and the relay path; and transceiving data via the selected path.
Abstract:
A data transceiving apparatus and method in a centralized MAC-based wireless communication system are provided. The data transceiving method of a centralized MAC-based device may include: setting a direct path to a device and a relay path to a piconet coordinator (PNC); selecting any one of the direct path and the relay path; and transceiving data via the selected path.