Abstract: A data communication apparatus according to the present invention includes a channel determination unit for determining frequency channels to be monitored on the basis of a current location of the ship station, a performance measurement unit for measuring channel performance for each of the determined frequency channels, a channel selection unit for selecting one frequency channel from among the determined frequency channels on the basis of the measured channel performance, and a data communication unit for performing data communication with the coast station using the selected frequency channel.

Abstract: Disclosed are an apparatus for transmitting multi-carrier signals, including: a signal spreading unit configured to generate band-spread signals through band spreading of a plurality of symbol-mapped signals; and a modulation unit configured to generate a modulation signal by mixing the band-spread signals with a plurality of sub-carriers and adding up the mixed band-spread signals, and a method for transmitting multi-carrier signals.

Abstract: Provided are a method and apparatus for transmitting control information and packet data. The method includes generating control channels which transmit the control information; generating control indication channel which indicates whether the control channels are transmitted or not; generating data channels in order to transmit the packet data based on the control information; multiplexing the control channels, the control indication channels, and the data channels; and transmitting the control channels, the control indication channels, and the data channels. According to the present invention, when control information and packet data are transmitted in downlink, by transmitting additional information indicating whether control channels are transmitted or not, resources not actually allocated to control channels can be allocated to data channel and the mobile station can receive data channel using the control indication information.

Abstract: The present invention relates to signal transmitting/receiving apparatuses. The signal transmitting apparatus includes an inverse discrete Fourier transform module, a cyclic prefix adding module, a preamble adding module, and a digital-analog converting module. The inverse discrete Fourier transform module receives modulated data, performs inverse discrete Fourier transform, and generates a first symbol. The cyclic prefix adding module adds a predetermined cyclic prefix to the first symbol, and generates a second symbol. The preamble adding module adds a predetermined preamble to the second symbol, and generates a third symbol. The digital-analog converting module converts the third symbol including the cyclic prefix and the preamble into an analog symbol.

Abstract: Provided are a fixed station receiver for a Multi-Input Multi-Output (MIMO) communication system and an uplink adaptation method thereof. In the uplink adaptation method, a sounding reference signal (SRS) is received from a terminal including a plurality of transmission antennas. A complex channel matrix (H) corresponding to a channel response and a noise variance (?2) corresponding to a noise power is calculated from the sounding reference signal. A signal-to-interference and noise ratio (SINR) on each transmission symbol is calculated with reference to the complex channel matrix (H) and the noise variance (?2). A pre-coding matrix of the terminal is selected with reference to the signal-to-interference and noise ratio (SINR).

Abstract: Provided is a data transmission system for transmitting control information from a terminal to a base station. The terminal may multiplex the control information, and may transmit the multiplexed control information to the base station using a plurality of transmit antennas. The base station may receive the multiplexed control information and combine the control information. The base station may transmit data to the terminal using the control information.

Abstract: Provided is a decoding apparatus and method using orthogonal space-time block codes (OSTBCs) robust against timing errors. The decoding apparatus may include: a cyclic prefix removal unit to receive a signal, and to remove a cyclic prefix in the signal; an inverse discrete Fourier transform (IDFT) unit to apply an IDFT to the signal with the removed cyclic prefix; a guard band removal unit to remove a guard band in the inverse discrete Fourier transformed signal, and to generate a complex matrix; a channel estimation unit to transmit a carrier corresponding to the complex matrix and channel status information associated with transmit and receive antennas; and a decoder to calculate a channel status vector with respect to a complex symbol included in the complex matrix, using the channel status information, and to calculate an inner product between the channel status vector and the complex matrix, to restore the complex symbol.

Abstract: Provided are a method and apparatus for transmitting control information and packet data. The method includes generating control channels which transmit the control information; generating control indication channel which indicates whether the control channels are transmitted or not; generating data channels in order to transmit the packet data based on the control information; multiplexing the control channels, the control indication channels, and the data channels; and transmitting the control channels, the control indication channels, and the data channels. According to the present invention, when control information and packet data are transmitted in downlink, by transmitting additional information indicating whether control channels are transmitted or not, resources not actually allocated to control channels can be allocated to data channel and the mobile station can receive data channel using the control indication information.

Abstract: The present invention relates to signal transmitting/receiving apparatuses. The signal transmitting apparatus includes an inverse discrete Fourier transform module, a cyclic prefix adding module, a preamble adding module, and a digital-analog converting module. The inverse discrete Fourier transform module receives modulated data, performs inverse discrete Fourier transform, and generates a first symbol. The cyclic prefix adding module adds a predetermined cyclic prefix to the first symbol, and generates a second symbol. The preamble adding module adds a predetermined preamble to the second symbol, and generates a third symbol. The digital-analog converting module converts the third symbol including the cyclic prefix and the preamble into an analog symbol.