Abstract: A method for transmitting and receiving signals, performed by a terminal, in a C-RAN environment, includes sequentially transmitting fixed beams; receiving, from at least one first TRP determined as TRP(s) performing signal transmission and reception with the terminal among the plurality of TRPs, control information including information on whether to transmit a reference signal for reception of downlink data and an index of a transmission beam selected for uplink transmission; and receiving the downlink data from the at least one first TRP, and demodulating the downlink data by using a reception beam weight derived from a weight used for transmission of the fixed beams or by using the reference signal.

Abstract: An operation method performed by a terminal in a communication system may include: receiving, from a TRP, a first discovery signal including an identifier of a first transmission beam by using a first reception beam; measuring a first received signal strength of the first discovery signal; receiving, from the TRP, a second discovery signal including an identifier of a second transmission beam by using a second reception beam; measuring a second received signal strength of the second discovery signal; transmitting, to the TRP, first beam pair information including the identifier of the first transmission beam and an identifier of the first reception and the first received signal strength information; and transmitting, to the TRP, second beam pair information including the identifier of the second transmission beam and an identifier of the second reception beam and the second received signal strength information.

Abstract: A method for transmitting and receiving signals, performed by a terminal, in a C-RAN environment, includes sequentially transmitting fixed beams; receiving, from at least one first TRP determined as TRP(s) performing signal transmission and reception with the terminal among the plurality of TRPs, control information including information on whether to transmit a reference signal for reception of downlink data and an index of a transmission beam selected for uplink transmission; and receiving the downlink data from the at least one first TRP, and demodulating the downlink data by using a reception beam weight derived from a weight used for transmission of the fixed beams or by using the reference signal.

Abstract: An apparatus and method for detecting synchronization and signals using block data processing in a receiving system are provided. To process an input signal, a cumulative matrix is obtained from an input vector signal for each frame generated from the signal. A primary eigenvector is extracted from the cumulative matrix, and the maximum value of a correlation vector is calculated from the extracted primary eigenvector. A time delay is detected by comparing the calculated maximum value of the correlation vector with a first threshold value, and a delay correlation vector is calculated from the detected time delay. Finally, synchronization and signals are detected by comparing the calculated delay correlation vector with a second threshold value.

Abstract: A method and apparatus for estimating a channel in a wireless local area network (WLAN) are provided. A channel estimation apparatus may include a channel estimation information combiner to combine at least one channel estimation information based on a difference between cyclic delay diversity (CDD) values, and a phase applier to generate a first phase value and to apply the first phase value to the combined channel estimation information.

Abstract: An apparatus and method for detecting synchronization and signals using block data processing in a receiving system are provided. To process an input signal, a cumulative matrix is obtained from an input vector signal for each frame generated from the signal. A primary eigenvector is extracted from the cumulative matrix, and the maximum value of a correlation vector is calculated from the extracted primary eigenvector. A time delay is detected by comparing the calculated maximum value of the correlation vector with a first threshold value, and a delay correlation vector is calculated from the detected time delay. Finally, synchronization and signals are detected by comparing the calculated delay correlation vector with a second threshold value.

Abstract: Disclosed are methods and apparatuses for power saving in a Wireless Local Area Network (WLAN) system. A method for communication may comprise receiving a capability notification frame including first capability-related information from a second station; and configuring a power saving mode of the first station based on the first capability-related information. According to the present invention, power consumption efficiency of the communication system can be enhanced.

Abstract: Provided is a method and apparatus for estimating a frequency offset in a wireless local area network (WLAN), the apparatus including a field information combiner to combine a training sequence and a control field signal, and a frequency offset estimator to estimate a frequency offset based on information obtained by combining the training sequence and the control field signal.

Abstract: A method and apparatus for estimating a channel in a wireless local area network (WLAN) are provided. A channel estimation apparatus may include a channel estimation information combiner to combine at least one channel estimation information based on a difference between cyclic delay diversity (CDD) values, and a phase applier to generate a first phase value and to apply the first phase value to the combined channel estimation information.

Abstract: Provided is a user identification method and apparatus in a multi-user wireless communication system, the method including generating first identification information by reflecting masking identification (ID) information to group ID information associated with a received signal, generating second identification information based on a correspondence relationship between the generated first identification information and possible group ID (PGU) information transferred from an available access point (AP), and determining a user position based on the generated second identification information.

Abstract: Provided is a data transmission method and apparatus for maximizing data transmission efficiency by transmitting data through a flexible network transition in a network linked with a heterogeneous system.

Abstract: Disclosed are a signal distortion component adjusting apparatus and method capable of adjusting error vector magnitude of subcarriers of a predetermined position by adjusting a signal distortion component occurring while decreasing a peak to average power ratio (PAPR) in a communication system of an orthogonal frequency division multiplexing (OFDM) technology or an orthogonal frequency division multiple access (OFDMA) scheme, and a system using the same. The present invention includes a signal distortion component adjusting unit to add an additional signal distortion component Pe((n+N/2) % N) to a signal distortion component e(n) that is obtained by subtracting a threshold Th value, set to decrease peak power, from an absolute value of a time domain signal x(n) of an input signal, and to thereby adjust the signal distortion component. The present invention may transmit a highly reliable signal by adjusting error vector magnitude of subcarrier of a frequency domain.

Abstract: The method for transmitting a signal of an orthogonal frequency division multiplexing type according to an exemplary embodiment of the present invention has a configuration allowing a radio unit (RU) to perform a component adding a compression component and a decompression component before/after a serial interface interlocking between a digital unit (DU) and the radio unit (RU) and a component inserting a cyclic prefix (CP) into a signal so as to secure orthogonality of an orthogonal frequency division multiplexing (OFDM) signal, in a structure in which a base station is physically divided into the DU and the RU.

Abstract: An apparatus for canceling interference includes a plurality of converters, a plurality of interference cancellation units, a plurality of variance detectors, and an output selecting unit. The plurality of converters converts a plurality of received signals to a plurality of frequency domain signals, respectively. The plurality of interference cancellation units cancel interference in the plurality of frequency domain signals using a plurality of interference cancellation schemes to generate a plurality of interference-canceled signals corresponding to the plurality of interference cancellation schemes, respectively. The plurality of variance detectors measure a plurality of amounts of residual interference corresponding to the plurality of interference-canceled signals, respectively.

Abstract: When a base station of a time division duplex based mobile communication system receives an initial ranging request signal from a subscriber station, the base station generates initial ranging information including delay time information to the subscriber station, and receives uplink data delayed and transmitted using a delay time from the subscriber station. Also, when the subscriber station transmits an initial ranging request signal to the base station and receives initial ranging information including delay time information from the base station, the subscriber station establishes a transmission parameter value by using the transmission parameter value included in the initial ranging information and transmits uplink data by using the established delay time.

Abstract: Disclosed is a method and apparatus for composing a received symbol signal modulated with a bit reflected Gray code into bit information. According to an embodiment of the present invention, a positive integer of the received symbol signal having bits is assigned according to the Gray mapping rule, and a sign is determined. A value that is indicative of an arrangement of the bits constituting the received symbol signal is calculated. A boundary value in at least one bit group consisting of the bits constituting the received symbol signal is acquired, and a difference from an absolute value of the received symbol signal is calculated. The received symbol signal is converted into information per bit using a value of the received symbol signal based on the positive integer and the determined sign, the value that is indicative of the bit arrangement, and the difference from the absolute value.

Abstract: Disclosed are a signal distortion component adjusting apparatus and method capable of adjusting error vector magnitude of subcarriers of a predetermined position by adjusting a signal distortion component occurring while decreasing a peak to average power ratio (PAPR) in a communication system of an orthogonal frequency division multiplexing (OFDM) technology or an orthogonal frequency division multiple access (OFDMA) scheme, and a system using the same. The present invention includes a signal distortion component adjusting unit to add an additional signal distortion component Pe((n+N/2) % N) to a signal distortion component e(n) that is obtained by subtracting a threshold Th value, set to decrease peak power, from an absolute value of a time domain signal x(n) of an input signal, and to thereby adjust the signal distortion component. The present invention may transmit a highly reliable signal by adjusting error vector magnitude of subcarrier of a frequency domain.

Abstract: The method for transmitting a signal of an orthogonal frequency division multiplexing type according to an exemplary embodiment of the present invention has a configuration allowing a radio unit (RU) to perform a component adding a compression component and a decompression component before/after a serial interface interlocking between a digital unit (DU) and the radio unit (RU) and a component inserting a cyclic prefix (CP) into a signal so as to secure orthogonality of an orthogonal frequency division multiplexing (OFDM) signal, in a structure in which a base station is physically divided into the DU and the RU.

Abstract: The present invention relates to a method and apparatus for estimating a channel in a mobile communication network. In particular, the present invention relates to a method of estimating a channel under a channel environment where interference between neighboring base stations exists in a mobile communication network using an orthogonal frequency division multiplexing (OFDM) method. In order to estimate a channel, one cluster is divided into two sub-clusters, and pilot sub-carrier signals included in at least one sub-cluster in an OFDM symbol direction are used. Therefore, it is possible to further improve performance as compared to a method of estimating a channel by using pilot sub-carriers included in one cluster.

Abstract: Disclosed is a method of detecting signals at a receiver of a communication system with a multiple input multiple output antenna. With the signal detection method, a square of the distance between a received signal vector and a channel status-considered transmission symbol vector is calculated first, and the square of the distance is then classified into first and second components. The first component is minimized to calculate a plurality of first soft symbol estimates. A solution set of the first component is calculated on the basis of the plurality of first soft symbol estimates. The second component is minimized to calculate a plurality of second soft symbol estimates. A solution set of the second component is calculated on the basis of the plurality of second soft symbol estimates. A final solution set is calculated by doing the sum of the first component solution set and the second component solution.