Abstract: The present disclosure provides a method and a receiver for detecting synchronization in a Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) system. The receiver includes a reception unit that receives a synchronization signal including an interference signal from at least one adjacent cell; and a synchronization detector that cancels the interference signal included in the synchronization signal based on a serial interference cancellation, and detects the synchronization based on the synchronization signal, from which the interference signal is canceled.

Abstract: A multi-path search apparatus and a method in a wireless communication system are provided. The multi-path search apparatus includes a correlator configured to get a 1st correlation value between a received signal and a 1st code, and to get a 2nd correlation value between the received signal and a 2nd code, a coupler configured to couple the 1st correlation value and the 2nd correlation value, and a multi-path information generator configured to get the correlation energy of the output of the coupler and to generate multi-path information.

Abstract: The present disclosure provides a method and a receiver for detecting synchronization in a Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) system. The receiver includes a reception unit that receives a synchronization signal including an interference signal from at least one adjacent cell; and a synchronization detector that cancels the interference signal included in the synchronization signal based on a serial interference cancellation, and detects the synchronization based on the synchronization signal, from which the interference signal is canceled.

Abstract: A method of acquiring initial synchronization in a code division multiple access mobile communication system is provided. The method includes quantizing a received signal into a plurality of levels, calculating correlation values of the quantized received signal and a local code, calculating absolute values of the correlation values, and detecting a position of a maximum value which exceeds a threshold among the absolute values and an ID of a downlink synchronization (SYNC-DL) sequence and determining timing values of available cells and energy values corresponding to the timing values.

Abstract: A method and an apparatus for acquiring downlink frame synchronization are provided. The method includes phase-rotating a mid-amble of a first Time Slot (TS) of a received sub-frame within an area and estimating a Channel Impulse Response (CIR), calculating a Maximum Likelihood (ML) between a downlink synchronization code of the received sub-frame and a downlink synchronization code generated in a terminal by using the estimated CIR, correlating downlink synchronization codes of a plurality of sub-frames and the downlink synchronization code generated and calculating ML values of the plurality of sub-frames with respect to the plurality of sub-frames corresponding to M Transmission Time Intervals (TTIs), and calculating hypothesis values of hypotheses according to a frequency interval and a phase offset of the generated downlink synchronization code based on the calculated ML values of the plurality of sub-frames and drawing a frequency offset and a hypothesis corresponding to a maximum value.

Abstract: A multi-path search apparatus and a method in a wireless communication system are provided. The multi-path search apparatus includes a correlator configured to get a 1st correlation value between a received signal and a 1st code, and to get a 2nd correlation value between the received signal and a 2nd code, a coupler configured to couple the 1st correlation value and the 2nd correlation value, and a multi-path information generator configured to get the correlation energy of the output of the coupler and to generate multi-path information.

Abstract: A method and an apparatus for acquiring downlink frame synchronization are provided. The method includes phase-rotating a mid-amble of a first Time Slot (TS) of a received sub-frame within an area and estimating a Channel Impulse Response (CIR), calculating a Maximum Likelihood (ML) between a downlink synchronization code of the received sub-frame and a downlink synchronization code generated in a terminal by using the estimated CIR, correlating downlink synchronization codes of a plurality of sub-frames and the downlink synchronization code generated and calculating ML values of the plurality of sub-frames with respect to the plurality of sub-frames corresponding to M Transmission Time Intervals (TTIs), and calculating hypothesis values of hypotheses according to a frequency interval and a phase offset of the generated downlink synchronization code based on the calculated ML values of the plurality of sub-frames and drawing a frequency offset and a hypothesis corresponding to a maximum value.

Abstract: A method of acquiring initial synchronization in a code division multiple access mobile communication system is provided. The method includes quantizing a received signal into a plurality of levels, calculating correlation values of the quantized received signal and a local code, calculating absolute values of the correlation values, and detecting a position of a maximum value which exceeds a threshold among the absolute values and an ID of a downlink synchronization (SYNC-DL) sequence and determining timing values of available cells and energy values corresponding to the timing values.

Abstract: An apparatus and a method for interference cancellation in a Multiple Input Multiple Output (MIMO) wireless communication system. The method for interference cancellation includes equalizing first reception signals received through two or more reception antennas to estimate transmission signals transmitted through two or more transmission antennas, generating two or more second reception signals in which a mutual interference between the transmission signals is removed from the first reception signals by using the estimated transmission signals, independently equalizing the generated two or more second reception signals, and combining the independently equalized two or more second reception signals to estimate a transmission signal in which an interference is removed.

Abstract: An apparatus and a method for interference cancellation in a Multiple Input Multiple Output (MIMO) wireless communication system. The method for interference cancellation includes equalizing first reception signals received through two or more reception antennas to estimate transmission signals transmitted through two or more transmission antennas, generating two or more second reception signals in which a mutual interference between the transmission signals is removed from the first reception signals by using the estimated transmission signals, independently equalizing the generated two or more second reception signals, and combining the independently equalized two or more second reception signals to estimate a transmission signal in which an interference is removed.

Abstract: A method for performing Forward Error Correction (FEC) in a Turbo-Bell Labs Layered Space-Time (BLAST) Multiple-Input Multiple-Output (MIMO) communication system. The FEC method includes performing soft decision on a frame received via a plurality of antennas; performing iterative decoding on the soft decision result value a predetermined number of times, and outputting Log Likelihood Ratio (LLR) values for information bits and first parity bits constituting the frame; generating second parity bits by coding information bits calculated from the LLR values, and comparing the first parity bits calculated from the LLR values with the coded second parity bits; and if the first parity bits are identical to the second parity bits, outputting the information bits, determining that there is no error, and if the first parity bits are not identical to the second parity bits, feeding back the LLR values as a-priori information of the soft decision, and returning to the performing of soft decision.

Abstract: An apparatus and method for estimating a frequency offset in an Orthogonal Frequency Division Multiplexing (OFDM) system are provided. Two time domain signals are generated from one received OFDM symbol through two observation windows with different delay times. The two time domain signals are compensated for a candidate frequency offset. A discrete Fourier transform process and a phase compensation process in a frequency domain are performed. A difference between two frequency domain signals compensated for a phase difference is computed with respect to each candidate frequency offset. For all candidate frequency offsets, difference values are compared with each other. A candidate frequency offset mapped to a minimum difference value is detected as an optimal frequency offset. The frequency offset can be more exactly estimated without consuming a bandwidth and increasing hardware complexity of a receiver.

Abstract: A method for performing Forward Error Correction (FEC) in a Turbo-Bell Labs Layered Space-Time (BLAST) Multiple-Input Multiple-Output (MIMO) communication system. The FEC method includes performing soft decision on a frame received via a plurality of antennas; performing iterative decoding on the soft decision result value a predetermined number of times, and outputting Log Likelihood Ratio (LLR) values for information bits and first parity bits constituting the frame; generating second parity bits by coding information bits calculated from the LLR values, and comparing the first parity bits calculated from the LLR values with the coded second parity bits; and if the first parity bits are identical to the second parity bits, outputting the information bits, determining that there is no error, and if the first parity bits are not identical to the second parity bits, feeding back the LLR values as a-priori information of the soft decision, and returning to the performing of soft decision.

Abstract: An apparatus and method of detecting whether data exists in a received signal while a mobile communication terminal is in discontinuous transmission mode. The apparatus and method comprises generating and transmitting a forward power control command for providing the forward power control, and performing forward power control in a mobile communication system. According to the forward power control method, a power control command is generated based on a received frame including a plurality of slots each of which includes power control bits.

Abstract: Disclosed is a mobile station for determining a data rate for a packet data service in a mobile communication system including a base station, and the mobile station being provided with a voice service and a packet data service from the base station. In the mobile station, a receiver receives orthogonal code allocation information indicating the number of orthogonal codes allocated for the packet data service, a measurer measures a CIR using a received pilot channel, and a controller determines a data rate corresponding to the measured CIR, controls the determined data rate based on the number of the allocated orthogonal codes, and determines a controlled data rate.

Abstract: An apparatus and method for estimating a frequency offset in an Orthogonal Frequency Division Multiplexing (OFDM) system are provided. Two time domain signals are generated from one received OFDM symbol through two observation windows with different delay times. The two time domain signals are compensated for a candidate frequency offset. A discrete Fourier transform process and a phase compensation process in a frequency domain are performed. A difference between two frequency domain signals compensated for a phase difference is computed with respect to each candidate frequency offset. For all candidate frequency offsets, difference values are compared with each other. A candidate frequency offset mapped to a minimum difference value is detected as an optimal frequency offset. The frequency offset can be more exactly estimated without consuming a bandwidth and increasing hardware complexity of a receiver.

Abstract: A device and method for controlling communication on a reverse link in a mobile communication system includes a measurer, a controller, and a reverse link transmitter according to an embodiment of the present invention. The measurer detects a power control bit from a channel signal received on a forward link and measures the reception strength of the channel signal using the detected power control bit. The controller compares the reception strength with a threshold and generates a signal for controlling transmission on a reverse link if the channel status of the forward link is determined to be bad during the comparison. The reverse link transmitter stops channel transmission on the reverse link in response to the transmission control signal.

Abstract: Disclosed is a base station transmission apparatus in a mobile communication system using transmit antenna diversity between a base station with a plurality of antennas and a mobile station. A modulator generates a complex symbol in response to a coded symbol. A first spreader generates a plurality of different complex symbols in response to the complex symbol, and generates a plurality of first spread complex symbols by spreading the generated complex symbols with a first orthogonal code assigned to the mobile station. A second spreader generates a plurality of same complex symbols in response to the complex symbol from the modulator, spreads the same complex symbols with a second orthogonal code, and generates a plurality of second spread complex symbols by multiplying the spread complex symbols by weights for the antennas, determined based on feedback information indicating reception status of a base station signal. A summer sums up the first complex symbols and the second complex symbols.

Abstract: A receiving device in a multi-carrier CDMA communication system. In the receiving device, a time compensation means has a time tracker for each of signals received on multi-carriers and generates a time delay compensation signal by combining time errors of the carriers received from the time trackers. A first PN sequence generator generates a first PN sequence whose time delay is compensated for by the time delay compensation signal. A plurality of PN despreaders PN-despread the signals received on the multi-carriers by the first PN sequence. A frequency compensation means detects pilot signals corresponding to the PN-despread signals, generates frequency error signals for the carriers by the detected pilot signals, and compensates for frequency errors of the signals received on the multi-carriers. A phase compensation means compensates for phases for the carriers using the PN-despread signals and the pilot signals. A multiplexer multiplexes the phase-compensated signals.

Abstract: An apparatus and method of detecting whether data exists in a received signal while a mobile communication terminal is in discontinuous transmission mode. The apparatus and method comprises generating and transmitting a forward power control command for providing the forward power control, and performing forward power control in a mobile communication system. According to the forward power control method, a power control command is generated based on a received frame including a plurality of slots each of which includes power control bits.