Abstract: Embodiments of the present invention may provide an apparatus and a method for transmitting and receiving a random access channel (RACH) in a single carrier-frequency division multiple access (SC-FDMA) system. A frequency domain RACH signal may be mapped to a localized sub-frequency band of an entire frequency band available to the SC-FDMA system. A guard band including at least one sub carrier may be allocated between the RACH signal band and other channel signal bands. A guard time may be allocated between the RACE signal and other channel signals in the time domain. The RACH signal may include a short message including information related to a mobile station. The RACE signal may be detected in a frequency based method, a time based method or a sliding matched filter based method. Receiver complexity can be decreased if the RACH signal includes a CAZAC code sequence for a preamble. In such a case, a receive delay may be simply calculated and then adjusted more accurately.

Abstract: Embodiments of the present invention may provide an apparatus and a method for transmitting and receiving a random access channel (RACH) in a single carrier-frequency division multiple access (SC-FDMA) system. A frequency domain RACH signal may be mapped to a localized sub-frequency band of an entire frequency band available to the SC-FDMA system. A guard band including at least one sub carrier may be allocated between the RACH signal band and other channel signal bands. A guard time may be allocated between the RACE signal and other channel signals in the time domain. The RACH signal may include a short message including information related to a mobile station. The RACH signal may be detected in a frequency based method, a time based method or a sliding matched filter based method. Receiver complexity can be decreased if the RACH signal includes a CAZAC code sequence for a preamble. In such a case, a receive delay may be simply calculated and then adjusted more accurately.

Abstract: Embodiments of the present invention may provide an apparatus and a method for transmitting and receiving a random access channel (RACH) in a single carrier-frequency division multiple access (SC-FDMA) system. A frequency domain RACH signal may be mapped to a localized sub-frequency band of an entire frequency band available to the SC-FDMA system. A guard band including at least one sub carrier may be allocated between the RACH signal band and other channel signal bands. A guard time may be allocated between the RACE signal and other channel signals in the time domain. The RACH signal may include a short message including information related to a mobile station. The RACH signal may be detected in a frequency based method, a time based method or a sliding matched filter based method. Receiver complexity can be decreased if the RACH signal includes a CAZAC code sequence for a preamble. In such a case, a receive delay may be simply calculated and then adjusted more accurately.

Abstract: Embodiments of the present invention may provide an apparatus and a method for transmitting and receiving a random access channel (RACH) in a single carrier-frequency division multiple access (SC-FDMA) system. A frequency domain RACH signal may be mapped to a localized sub-frequency band of an entire frequency band available to the SC-FDMA system. A guard band including at least one sub carrier may be allocated between the RACH signal band and other channel signal bands. A guard time may be allocated between the RACE signal and other channel signals in the time domain. The RACH signal may include a short message including information related to a mobile station. The RACE signal may be detected in a frequency based method, a time based method or a sliding matched filter based method. Receiver complexity can be decreased if the RACH signal includes a CAZAC code sequence for a preamble. In such a case, a receive delay may be simply calculated and then adjusted more accurately.

Abstract: Embodiments of the present invention may provide an apparatus and a method for transmitting and receiving a random access channel (RACH) in a single carrier-frequency division multiple access (SC-FDMA) system. A frequency domain RACH signal may be mapped to a localized sub-frequency band of an entire frequency band available to the SC-FDMA system. A guard band including at least one sub carrier may be allocated between the RACH signal band and other channel signal bands. A guard time may be allocated between the RACH signal and other channel signals in the time domain. The RACH signal may include a short message including information related to a mobile station. The RACH signal may be detected in a frequency based method, a time based method or a sliding matched filter based method. Receiver complexity can be decreased if the RACH signal includes a CAZAC code sequence for a preamble. In such a case, a receive delay may be simply calculated and then adjusted more accurately.

Abstract: An apparatus and a method for interference cancellation using a multi-user multiple input multiple output (MU-MIMO) scheme in a single carrier frequency division multiple access (SC-FDMA) system are disclosed. Received data of every terminal are classified into first received data and second received data. The first received data has lower reliability and the second received data has higher reliability than the first received data. The second received data is transmitted to an upper layer. Interference signals are formed with the second received data based on a channel estimation value. The interference signals are removed from the first received data, and the interference signal free first received data is transmitted to the upper layer.

Abstract: An apparatus and a method for interference cancellation using a multi-user multiple input multiple output (MU-MIMO) scheme in a single carrier frequency division multiple access (SC-FDMA) system are disclosed. Received data of every terminal are classified into first received data and second received data. The first received data has lower reliability and the second received data has higher reliability than the first received data. The second received data is transmitted to an upper layer. Interference signals are formed with the second received data based on a channel estimation value. The interference signals are removed from the first received data, and the interference signal free first received data is transmitted to the upper layer.

Abstract: An apparatus and method for maximizing throughout for HARQ transmissions is provided. Systematic and prodeduralized RV selection is facilitated by determining the parameter “s” by using two important factors affecting the system throughout, specifically the coding gain varying according to the code rate and the balance between energy per systematic bit and energy per parity bit.

Abstract: Apparatus and method for determining a fixed point in a mobile communication system are disclosed. An initial fixed point is set through simulation and a saturation for an output of a target device is compared with a reference saturation. Then, the position of the initial fixed point is adaptively changed according to the change in the output range of the target device. Therefore, when a floating point is converted into a fixed point, the performance of the system can be improved while the complexity of the hardware can be reduced.

Abstract: Embodiments of the present invention may provide an apparatus and a method for transmitting and receiving a random access channel (RACH) in a single carrier-frequency division multiple access (SC-FDMA) system. A frequency domain RACH signal may be mapped to a localized sub-frequency band of an entire frequency band available to the SC-FDMA system. A guard band including at least one sub carrier may be allocated between the RACH signal band and other channel signal bands. A guard time may be allocated between the RACH signal and other channel signals in the time domain. The RACH signal may include a short message including information related to a mobile station. The RACH signal may be detected in a frequency based method, a time based method or a sliding matched filter based method. Receiver complexity can be decreased if the RACH signal includes a CAZAC code sequence for a preamble. In such a case, a receive delay may be simply calculated and then adjusted more accurately.

Abstract: An apparatus and method for maximizing throughout for HARQ transmissions is provided. Systematic and prodeduralized RV selection is facilitated by determining the parameter “s” by using two important factors affecting the system throughout, specifically the coding gain varying according to the code rate and the balance between energy per systematic bit and energy per parity bit.

Abstract: A communication system having multiple channels is disclosed. An apparatus for controlling outer loop power in the communication system having the multiple channels includes a step adjustment unit for re-setting height of a step size for power controlling with reference to a CRC result, when the CRC result is received from a base station; and a power controller for determining a target signal to interference ratio (SIR) with reference to the CRC result and the re-set step size information, and transmitting the determined target SIR to the base station. Power controlling operation can be more effectively performed in the communication system having the multiple channels.

Abstract: Apparatus and method for determining a fixed point in a mobile communication system are disclosed. An initial fixed point is set through simulation and a saturation for an output of a target device is compared with a reference saturation. Then, the position of the initial fixed point is adaptively changed according to the change in the output range of the target device. Therefore, when a floating point is converted into a fixed point, the performance of the system can be improved while the complexity of the hardware can be reduced.

Abstract: An adaptive beamforming apparatus and method of an array antenna in a communication system. First, a tentative symbol decision value is obtained by processing a traffic signal vector, and a final updated coefficient value is obtained by performing a least mean square (LMS) algorithm at least once with respect to the tentative symbol decision value and a pilot signal vector on the assumption that the tentative symbol decision value is a transmitted symbol value. Then an adaptive beam which corresponds to a final symbol decision value is formed using the traffic signal vector and the final updated coefficient value.