Abstract: An apparatus and method for generating a codebook in a wireless communication system are disclosed. The codebook generation method includes determining one or more dominant singular vectors in a channel matrix for antennas and setting each of the dominant singular vectors as a random non-zero vector, generating a first codebook having codewords, a minimum distance between the code-words being maximized, using the random non-zero vector in a region that includes unit norm vectors each having a Euclidean distance to each of the dominant singular vectors, equal to or less than a predetermined value, generating a second codebook corresponding to a unitary matrix that rotates the random non-zero vector toward the dominant singular vectors, and generating a final codebook using the first and second codebooks.

Abstract: The present invention relates to a method and to an apparatus for transmitting/receiving data in a relay communication system. The method comprises the steps of: setting, as a guard band, the first predetermined number of symbol transmission slots of a data transmission period in a subframe resource element of a downlink channel constituted by a control signal transmission period to which a control signal is allocated and the data transmission period to which downlink data is allocated; allocating reference signals to symbols of the data transmission period; puncturing the symbols corresponding to the guard band from among the symbols to which said reference signals are allocated; and transmitting signals to which said reference signals are allocated.

Abstract: Disclosed are an apparatus and method for determining a frame structure for reducing interference between users using the same frequency band in a communication system using a cognitive radio, the method including, collecting channel status information related to a primary user with a priority to occupancy of a predetermined frequency band, executing spectrum sensing for the frequency band to check whether the primary user's traffic exists, deciding a length of a data frame to be transmitted in consideration of interference to the primary user based upon the collected channel status information if a channel in which the primary user's traffic is not present is sensed through the spectrum sensing, constructing a data frame based upon the decided frame length to transmit via the sensed channel, and re-executing the spectrum sensing for the channel, if data to be additionally transmitted exists, and rechecking whether the primary user's traffic is present.

Abstract: A method for cooperative control of power among base stations and a base station device which performs the same are discussed. A first receiving unit is configured such that a specific base station in a cooperative unit receives, from a specific terminal located on a cell edge of the specific base station, token value information which indicates an average transmission rate of the specific terminal and the up-to-date level of satisfaction of the minimum average transmission rate of the specific terminal. A second receiving unit receives, from one or more other base stations in the cooperative unit, information containing an average transmission rate of terminals located on edges of each of the base stations, token values of terminals located on cell edges of each of the base stations, and the current power levels of each of one or more base stations.

Abstract: Systems and methodologies are described that facilitate searches for a cell in a wireless communication environment. A mobile device can employ a searcher that can detect timing information respectively associated with PSCs and cells to determine the cell with the highest correlation. The searcher can detect SSCs, which can include detecting associated phase information, to determine the SSC with the highest correlation, CP length, and/or other information to facilitate identifying a desired cell having the strongest signal to establish communication between the mobile device and the desired cell. PSCs respectively associated with cells can have different positions in the symbol sequences, and SSCs can respectively be phase shifted at different angles to facilitate detection and identification of a cell(s), where a PSC can be utilized as a phase reference by the associated SSC.

Abstract: Disclosed are a method for transmitting scheduling information in a mobile communication system and a femtocell base station using the method. A femtocell base station transmits scheduling information using a layered scheduling system in which the femtocell base station receives an allocated resource from a macrocell base station, and allocates the resource to femtocell users within a resource region thereof.

Abstract: A method for signal transmission in a wireless communication system is provided. The method includes: transmitting backhaul resource allocation information by a base station to a relay node; decoding the backhaul resource allocation information by the relay node; and transmitting backhaul downlink control information and backhaul downlink data by the base station to the relay node, wherein a start position of a symbol for transmitting the backhaul downlink control information is fixed to a specific symbol of a backhaul link subframe, and the backhaul resource allocation information includes information on a radio resource for transmitting the backhaul downlink data.

Abstract: Disclosed are a method and apparatus capable of enhancing a closed loop multi-input multi-output (MIMO) capacity through distributed discrete power control in the case of cooperatively transmitting information to multiple users through a downlink.

Abstract: A method of transmitting data in a multi-cell cooperative wireless communication system is provided. The method includes dividing the data into common data and private data, determining a transmission rate and/or a transmission power of the common data and the private data, respectively and transmitting the common data and the private data at the determined transmission rate and/or transmission power. It is possible to mitigate inter-cell interference and improve the performance of the system.

Abstract: A method for processing traffic destined for a BS received from one or more terminals in an intermediate access point supporting two or more communication schemes is disclosed. The method includes receiving traffic from the one or more terminals according to a first communication scheme, measuring a congestion level of the received traffic, transmitting a first traffic being part of the received traffic to a second intermediate access point according to a second communication scheme, if the congestion level is a predetermined threshold or higher, and transmitting a second traffic being remaining traffic of the received traffic except the first traffic to the BS.

Abstract: Disclosed is a method for receiving data in a Multi Input Multi Output (MIMO) system, the method comprising: decoding data transmitted from a transmitter by using one beam-forming vector included in a codebook that beam-forming vectors are formed in a hierarchical structure according to at least one of change directions of radio channels, the number of channel change directions, and a change rate; determining whether to update the beam-forming vector based on the radio channel changes; selecting other beam-forming vector included in the codebook having a hierarchical structure when it is determined that update for the beam-forming vector is required; feed-backing information about an index indicating where the selected beam-forming vector is located in the hierarchical structure of the codebook to the transmitter; and decoding data received from the transmitter by using the selected beam-forming vector.

Abstract: Provided are a method and apparatus for the feedback of channel information in a wireless communication system. User equipment transmits a recommended rank to a base station. The user equipment receives, from the base station, an indicating rank that has been determined in consideration of the recommended rank, and transmits a channel status determined on the basis of the indicating rank to the base station.

Abstract: Disclosed are a feedback-transmitting method and data-transmitting method, and a method for generating a codebook that can be used in a system such as LTE-A. When multiple base stations operate in a cooperative mode, using a codebook generated according to the present invention, an existing codebook for single cell transmission can be used to generate a codebook for cooperative transmission.

Abstract: A method of transmitting PMI (precoding matrix indicator) information in an uplink MIMO system is disclosed.

Abstract: Provided is a method for transmitting a sounding reference signal (SRS) of a relay station. The method includes: receiving SRS parameters; allocating a radio resource by using the SRS parameters; and transmitting the SRS to a base station by using the radio resource, wherein the radio resource indicated by the SRS parameters includes a symbol in which a guard time for switching signal transmission and reception is located in a time domain.

Abstract: A cooperative multiple point transmission and reception (CoMP) method of a user equipment (UE) receiving signals from a plurality of base stations (BSs) comprises receiving a first signal from a serving BS, receiving a second signal from an interfering BS, and restoring data, included in the first signal, using the second signal. The second signal comprises a downlink signal, transmitted from the interfering BS to a UE connected to the interfering BS, and a dummy signal for canceling interference of the downlink signal with the first signal. In a wireless communication system composed of multiple cells, CoMP using DPC can be performed even without data sharing between the cells.

Abstract: The present invention relates to a method for transmitting a sounding reference signal from a terminal in an uplink coordinative multi-point (CoMP) communication system. Specifically, the method comprises the steps of: receiving parameters for transmitting a sounding reference signal from a serving base station included in a CoMP set; assigning a resource for the sounding reference signal on the basis of the parameters; and transmitting the sounding reference signal to the serving base station included in the CoMP set and to at least one neighboring base station according to the assigned resource, wherein basis sequences of the parameters for the sounding reference signal are different for base stations included in the CoMP set.

Abstract: The present invention discloses a method in which a base station transmits a downlink signal in a wireless communication system. In detail, the method comprises the following steps: allocating a transmitting resource to data symbols for transmitting downlink signals, in the direction of increasing a frequency index; and transmitting the downlink signal to a terminal, using the allocated resource. The frequency band of preset orthogonal frequency division multiplexing (OFDM) symbols, from among the transmitting resource, contains a control domain and a segment band. The step of allocating the transmitting resource comprises the step of puncturing the data symbol using a control channel, to which the control domain contained in the preset OFDM symbols is allocated.

Abstract: Techniques for multiplexing pilots in a wireless transmission are described. In one aspect, a transmitter station generates multiple pilot sequences for multiple transmit antennas, with each pilot sequence comprising pilot symbols sent in the time domain on a different set of subcarriers. The transmitter station further generates multiple pilot transmissions for the transmit antennas based on the pilot sequences. In another aspect, a transmitter station generates multiple pilot sequences for multiple transmit antennas based on frequency-domain code division multiplexing (FD-CDM) of a Chu sequence defined by a transmitter-specific value. The transmitter station further generates multiple pilot transmissions for the transmit antennas based on the pilot sequences.

Abstract: Successive interference cancellation is performed with improved computational efficiency while offering performance approaching that of full CRC-based successive interference cancellation. In a “blind” interference cancellation technique, reconstructed streams are used for interference cancellation without regard to whether the reconstructed streams were properly decoded. In a “semi-blind” interference cancellation technique, decoder outputs from linear equalization can be used instead of decoder outputs from successive interference cancellation in those cases where linear equalization produces accurate decoding but successive interference cancellation does not.