Abstract: Disclosed is an apparatus and method for encoding/decoding a space time block code in a mobile communication system using a multiple input multiple output scheme. In a transmitter employing a plurality of transmit antennas in the mobile communication system, if a signal to be transmitted is input, the transmit signal is pre-encoded according to a preset coding scheme, the pre-encoded signal is space-time mapped according to a number of the transmit antennas to employ a preset space time block coding scheme, and the space-time mapped signal is transmitted through the transmit antennas by applying the preset space time block coding scheme to the space-time mapped signal.

Abstract: An apparatus and method for SFBC coding and decoding in a communication system using a plurality of (Nt) Tx antennas are provided. In a transmitter using Nt transmit antennas, a pre-coder pre-codes an input symbol sequence using a pre-coding matrix. The pre-coding matrix is produced by puncturing a unitary matrix in a predetermined method. An encoder generates a plurality of vectors by grouping the symbols of the pre-coded symbol sequence by twos, space-frequency maps each of the vectors by encoding each of the vectors in an Alamouti coding scheme, and provides each of the space-frequency mapped symbols to a predetermined OFDM modulator.

Abstract: A mobile communication system receives a reception signal, and determines a first error value by using a first scheme, and a second error value by using a second scheme, and determines a first scheme application weight according to a difference between the first error value and the second error value, and a second scheme application weight according to the difference between the first error value and the second error value, and generates a third error value using a scheme that combines the first scheme to which the first scheme application weight is applied and the second scheme to which the second scheme application weight is applied, and determines a reception beam weight using the reception signal, the third error value, and an output signal generated by applying the reception beam to the reception signal, wherein the reception beam weight is used for generating the reception beam.

Abstract: A method for transmitting and receiving weight information for creating transmission/reception beams in a mobile communication system using a multiple input multiple output adaptive antenna array scheme. The method includes a receiver receiving a predetermined signal, and differentially providing weights to a first scheme and a second scheme for minimizing an error between the received signal and a predetermined reference signal, thereby obtaining a minimum error value. The receiver generates a despread signal by despreading the received signal, produces a reception weight for creation of a reception beam by the receiver through calculation using the despread signal and the minimum error value, and produces a transmission weight for creation of a transmission beam by a counterpart transmitter through calculation using the reception weight and the minimum error value.

Abstract: A method for receiving a signal from a radio unit in a base station having at least one reception antenna is disclosed. The method includes receiving a reception signal via the reception antenna, and generating an output signal using the reception signal and a reception beam weight for a previous time; calculating a cost function using a desired reception signal transmitted from the radio unit among the reception signal and the generated output signal; calculating a trace vector using the calculated cost function and the reception signal; updating the reception beam weight using the trace vector for a next time; and generating a reception beam by applying the updated reception beam weight.

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: 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: A joint channel and Direction of Arrival (DOA) estimation apparatus and method simplified to efficiently estimate a channel impulse response associated with a spatially selective transmission channel occurring in a mobile radio channel are provided. To uniformly process all directions, angles associated with a beam are predetermined according to a preset method. This selection calculates a linear system model with regular spatial sampling using regular spatial separation of beam angles. The novel beam forming compensates for a difference between an adaptive array antenna and a sector type antenna using appropriate beam steering according to the calculated linear system model, thereby improving performance and facilitating implementation.

Abstract: A method for generating a preamble sequence in an OFDM (Orthogonal Frequency Division Multiplexing) communication system that uses A sub-carriers in a frequency domain and uses N Tx (Transmission) antennas, includes the steps of: generating N sequences, each having a length of ‘B/N’, by dividing B sub-carriers from among the A sub-carriers by the ‘N’ indicative of the number of the Tx antennas; and mapping, for each of the N sequences, individual components of the sequence to the B/N sub-carriers from among the A sub-carriers on a one by one basis in order to assign the components of the sequence to the B/N sub-carriers, and assigning null data to remaining sub-carriers other than the B/N sub-carriers from among the A-sub-carriers, such that a preamble sequence of a corresponding Tx antenna is generated.

Abstract: A method for receiving a signal from a radio unit in a base station having at least one reception antenna is disclosed. The method includes receiving a reception signal via the reception antenna, and generating an output signal using the reception signal and a reception beam weight for a previous time; calculating a cost function using a desired reception signal transmitted from the radio unit among the reception signal and the generated output signal; calculating a trace vector using the calculated cost function and the reception signal; updating the reception beam weight using the trace vector for a next time; and generating a reception beam by applying the updated reception beam weight.

Abstract: In a radio communication system that transmits reference signals for identifying a plurality of base stations from the base station to mobile stations, base station identification patterns for identifying base stations are generated by providing a method for dividing a frequency domain in a frequency-time domain given with the frequency domain and a time domain into a plurality of sub-bands. Reference signal patterns are determined in a predetermined time domain within the time domain at each of the sub-bands. In this way, the number of base stations that can be identified is increased.

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.