Abstract: Disclosed is a method whereby a channel quality indicator is fed back by a terminal in a multiple-antenna wireless communication system. More specifically, the method comprises the steps of: receiving reference signals corresponding to a plurality of data streams from a base station; using the reference signals to calculate a channel quality indicator; and transmitting the calculated channel quality indicator to the base station; and, in the step in which the channel quality indicator is calculated, the channel quality indicator is calculated under the assumption that at least one of the reference signals has been transmitted using wither the spatial-multiplexing technique or the transmit diversity technique, depending on the feedback setting of the terminal.

Abstract: The present application discloses a method in which a base station transmits a reference signal sequence in a wireless communication system. In detail, the method comprises the steps of: generating a pseudo-random sequence using a first m-sequence and a second m-sequence; generating the reference signal sequence using the pseudo-random sequence; and transmitting the reference signal to a mobile station via antenna ports different from one another. The second m-sequence has an initial value containing parameters for discriminating reference signal sequences among users.

Abstract: A method of allocating a channel in a wireless local area network (WLAN) system is provided. The method includes generating a MAC protocol data unit (MPDU) to be transmitted to a target station (STA), generating a PLCP protocol data unit (PPDU) by attaching a physical layer convergence procedure (PLCP) header to the MPDU, and transmitting the PPDU to the STA, wherein the PLCP header includes channel allocation information for transmission of the PPDU.

Abstract: In a system having a plurality of cells participating in a Coordinated Multi-Point (CoMP) operation, a method for transmitting Reference Signals (RSs) to User Equipment (UE) includes generating, by Base Station (BS) included in each of the plurality of cells, a subframe including RSs for a UE located in the each of the plurality of cells, and transmitting the generated subframe to the UE by the BS. The RSs include RSs for channel measurement, and RSs for data demodulation, the plurality of cells are grouped according to frequency shift values applied to the RSs for channel measurement and RS allocation patterns are determined for two cells among the plurality of cells according to a predetermined rule.

Abstract: A method for efficiently scheduling virtual resource blocks to physical resource blocks is disclosed. In a wireless mobile communication system, for distributed mapping of consecutively allocated virtual resource blocks to physical resource blocks, when nulls are inserted into a block interleaver used for the mapping, they are uniformly distributed to ND divided groups of the block interleaver, which are equal in number to the number (ND) of physical resource blocks to which one virtual resource block is mapped.

Abstract: A method of transmitting a Physical Layer Convergence Procedure (PLCP) frame in a Very High Throughput (VHT) Wireless Local Area Network (WLAN) system includes generating a MAC Protocol Data Unit (MPDU) to be transmitted to a destination station (STA), generating a PLCP Protocol Data Unit (PPDU) by adding a PLCP header, including an L-SIG field containing control information for a legacy STA and a VHT-SIG field containing control information for a VHT STA, to the MPDU, and transmitting the PPDU to the destination STA. A constellation applied to some of Orthogonal Frequency Division Multiplex (OFDM) symbols of the VHT-SIG field is obtained by rotating a constellation applied to an OFDM symbol of the L-SIG field.

Abstract: A method for efficiently scheduling virtual resource blocks to physical resource blocks is disclosed. In a wireless mobile communication system, for distributed mapping of consecutively allocated virtual resource blocks to physical resource blocks, when nulls are inserted into a block interleaver used for the mapping, they are uniformly distributed to ND divided groups of the block interleaver, which are equal in number to the number (ND) of physical resource blocks to which one virtual resource block is mapped.

Abstract: Disclosed in a method for a terminal to receive a downlink signal in a multi user MIMO (MU-MIMO) wireless communication system. More specifically, the method comprises the steps of: receiving downlink control information (DCI) from a base station; obtaining a parameter for a downlink demodulating-reference signal (DM-RS) included in the downlink control information; receiving the downlink DM-RS specified to the terminal on the basis of the parameter; and receiving a downlink data signal on the basis of the downlink DM-RS specified in the terminal, wherein the parameter includes information on a rank which is set in the terminal and a logical antenna port in which the downlink DM-RS is defined.

Abstract: A method for efficiently scheduling virtual resource blocks to physical resource blocks is disclosed. In a wireless mobile communication system, for distributed mapping of consecutively allocated virtual resource blocks to physical resource blocks, when nulls are inserted into a block interleaver used for the mapping, they are uniformly distributed to ND divided groups of the block interleaver, which are equal in number to the number (ND) of physical resource blocks to which one virtual resource block is mapped.

Abstract: A method for transmitting data by applying a precoding matrix in an open-loop multiple input multiple output (MIMO) system is disclosed. The method comprises selecting a precoding matrix and applying the selected precoding matrix to data during initial transmission; selecting a precoding matrix and applying the selected precoding matrix to data to be retransmitted; and retransmitting the data to which the precoding matrix is applied, wherein an index of the precoding matrix applied to the data is determined based on the times of current retransmission times of the data and index of the precoding matrix applied during initial transmission of the data.

Abstract: A method for efficiently providing data and a reference signal (RS) when antennas are added to an existing system is provided. The method includes transmitting an RS in a downlink MIMO system that supports a first user equipment (UE) and a second UE, the first UE recognizing four predetermined transmitting antennas among eight transmitting antennas and the second UE recognizing the eight transmitting antennas, generating a subframe that can be recognized by both the first UE and the second UE and transmitting the generated subframe to the first UE and the second UE, where the first UE and the second UE recognize all orthogonal frequency division multiplexing (OFDM) symbols of the subframe.

Abstract: The present application discloses a method in which a base station transmits a reference signal sequence in a wireless communication system. In detail, the method comprises the steps of: generating a pseudo-random sequence using a first m-sequence and a second m-sequence; generating the reference signal sequence using the pseudo-random sequence; and transmitting the reference signal to a mobile station via antenna ports different from one another. The second m-sequence has an initial value containing parameters for discriminating reference signal sequences among users.

Abstract: The present application discloses a method for transmitting a downlink signal in a multi-antenna wireless communication system. In detail, the method comprises: a step of mapping a signal of a codeword domain to a signal of a layer domain; a step of mapping the signal of the layer domain to a signal of a virtual antenna port domain using a precoding matrix; and a step of transmitting the signal of the virtual antenna port domain to a physical antenna port, wherein the precoding matrix is changed in a channel measurement unit, and the signal of the layer domain is layer-permutated in the channel measurement unit. Preferably, the channel measurement unit is constituted by one or more resource blocks (RBs).

Abstract: A method for efficiently scheduling virtual resource blocks to physical resource blocks is disclosed. In a wireless mobile communication system, for distributed mapping of consecutively allocated virtual resource blocks to physical resource blocks, when nulls are inserted into a block interleaver used for the mapping, they are uniformly distributed to ND divided groups of the block interleaver, which are equal in number to the number (ND) of physical resource blocks to which one virtual resource block is mapped.

Abstract: A method of transmitting signals by a transmitting end in a wireless communication system comprises sharing control information related to reference signal with a receiving end; generating one or more precoded reference signals considering a given rank; allocating the one or more precoded reference signals to have a specific pattern within a subframe, wherein the specific pattern is varied depending on the control information; and transmitting the subframe through multiple antennas to the receiving end.

Abstract: A radio communication system is provided. An uplink transmission method of a user equipment in a radio communication system includes performing Fourier transform on one or more data sequences to generate one or more first frequency-domain sequences, applying precoding for multi-antenna transmission to the one or more first frequency-domain sequences to generate one or more second frequency-domain sequences; performing inverse Fourier transform on the one or more second frequency-domain sequences to generate one or more transmission symbols, and transmitting the one or more transmission symbols via multiple antennas.

Abstract: A method of transmitting signals by a transmitting end in a wireless communication system comprises sharing control information related to reference signal with a receiving end; generating one or more precoded reference signals considering a given rank; allocating the one or more precoded reference signals to have a specific pattern within a subframe, wherein the specific pattern is varied depending on the control information; and transmitting the subframe through multiple antennas to the receiving end.

Abstract: A method for transmitting channel quality information based on a differential scheme is disclosed. When channel quality information of a predetermined number of sub-bands selected by a receiver in a frequency selective channel is transmitted, total average channel information is transmitted. Channel information of the selected sub-bands is transmitted as sub-band differential information associated with average channel information. In this case, the sub-band differential information may be denoted by a specific value contained in a differential-value range including only positive (+) values. If at least two channel quality information is transmitted by a MIMO system, channel quality information of one channel is transmitted, then channel quality information of the other channel is transmitted as spatial differential information. In this case, the spatial differential information is denoted by a specific value contained in a differential-value range asymmetrical on the basis of “0”.

Abstract: The present invention relates to a method for operating a power save mode in a wireless LAN system. The method involves transmitting a power save multi-poll (PSMP) frame containing a power save mode (PSM) of a non-access point (AP) station (STA) to a first station and to a second station which are paired with an AP on the basis of multiple input multiple output (MIMO) technology. Information on the PSM contains downlink transmission start offset which indicates the point in time of starting a downlink transmission period, a downlink transmission duration which indicates the duration of the downlink transmission period, and transmission object station identification information. The method further involves transmitting a data frame to the first station and to the second station on the basis of the MIMO technology during the downlink transmission period.

Abstract: A method for transmitting downlink reference signal in a multi-antenna wireless communication system is disclosed. The method includes allocating RSs for a first antenna group to a subframe having a predetermined area with different access levels for user equipments having different access capabilities, pairing RSs for a second antenna group with RSs for the first antenna group, allocating the paired RSs to the predetermined area of the subframe in code division multiplexing, and transmitting the subframe on the downlink.