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 retransmitting data in synchronous Hybrid Automatic Repeat reQuest (HARQ) to support Multiple Input Multiple Output (MIMO) is disclosed. The method includes transmitting a plurality of unit data blocks to a receiver, receiving from the receiver a control channel signal including first feedback information indicating whether the transmission of the plurality of unit data blocks is successful, and retransmitting at least one of the plurality of unit data blocks according to a predetermined order, each unit data block in one Transmission Time Interval (TTI), if a rank is 1 and the first feedback information indicates that the transmission of the plurality of unit data blocks is failed.

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: Methods for receiving ACK/NACK signals in a mobile communication system are disclosed. One of the methods including receiving reference signal information and a resource block index corresponding to resource block allocated for transmission of data; identifying ACK/NACK resource information through the reference signal information and the resource block index; and receiving an ACK/NACK signal of the data using the ACK/NACK resource information.

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 for transmitting uplink signals, which include ACK/NACK signals, control signals other than the ACK/NACK signals, and data signals, is disclosed. The method comprises serially multiplexing the control signals and the data signals; sequentially mapping the multiplexed signals within a specific resource region in accordance with a time-first mapping method, the specific resource region including a plurality of symbols and a plurality of virtual subcarriers; and arranging the ACK/NACK signals at both symbols near symbols to which a reference signal of the plurality of symbols is transmitted. Thus, the uplink signals can be transmitted to improve receiving reliability of signals having high priority.

Abstract: A method of allocating resources for transmitting a signal in a Multiple-Input Multiple-Output (MIMO) wireless communication system is disclosed. The method includes allocating one or more spatial resources of a plurality of spatial resources corresponding to first Single Carrier-Frequency Division Multiple Access (SC-FDMA) symbols to a first transport block, allocating one or more other spatial resources of the plurality of spatial resources corresponding to the first SC-FDMA symbols to a second transport block, and allocating spatial resources corresponding to second SC-FDMA symbols to the first transport block and the second transport block.

Abstract: Transmitting an acknowledgement/negative acknowledgement (ACK/NACK) signal in association with a packet transmitted on an uplink is disclosed. The method includes the steps of receiving a packet transmitted from a user equipment, decoding the packet, and determining whether the packet has been successfully decoded, transmitting an ACK signal or a NACK signal, based on the decoding result. Different transmission powers are allocated for the ACK signal and the NACK signal. Alternatively, the transmission power for the NACK signal selectively has an OFF level. The present invention optimizes the transmission powers for downlink ACK/NACK signals in accordance with the required reception quality of each of the ACK/NACK signals, and thus, enables the system to operate efficiently.

Abstract: A method and system for transmitting and receiving data using a plurality of antennas are disclosed. The method of transmitting includes the steps of receiving feedback information from a receiving end, the feedback information including group selection information and weight values for the plurality of antennas, grouping the plurality of antennas into a plurality of antenna groups based on the group selection information included in the feedback information, and transmitting, to a receiving end, a plurality of data streams through the plurality of antenna groups, respectively, based on the weight values.

Abstract: A method for efficiently transmitting and receiving control information through a Physical Downlink Control Channel (PDCCH) is provided. When a User Equipment (UE) receives control information through a PDCCH, the received control information is set to be decoded in units of search spaces, each having a specific start position in the specific subframe. Here, a modulo operation according to a predetermined first constant value (D) is performed on an input value to calculate a first result value, and a modulo operation according to a predetermined first variable value (C) corresponding to the number of candidate start positions that can be used as the specific start position is performed on the calculated first result value to calculate a second result value and an index position corresponding to the second result value is used as the specific start position. Transmitting control information in this manner enables a plurality of UEs to efficiently receive PDCCHs without collisions.

Abstract: A method for efficiently transmitting and receiving control information through a Physical Downlink Control Channel (PDCCH) is provided. When a User Equipment (UE) receives control information through a PDCCH, the received control information is set to be decoded in units of search spaces, each having a specific start position in the specific subframe. Here, a modulo operation according to a predetermined first constant value (D) is performed on an input value to calculate a first result value, and a modulo operation according to a predetermined first variable value (C) corresponding to the number of candidate start positions that can be used as the specific start position is performed on the calculated first result value to calculate a second result value and an index position corresponding to the second result value is used as the specific start position. Transmitting control information in this manner enables a plurality of UEs to efficiently receive PDCCHs without collisions.

Abstract: Methods for receiving ACK/NACK signals in a mobile communication system are disclosed. One of the methods including receiving reference signal information and a resource block index corresponding to resource block allocated for transmission of data; identifying ACK/NACK resource information through the reference signal information and the resource block index; and receiving an ACK/NACK signal of the data using the ACK/NACK resource information.

Abstract: A method of acquiring information on a resource region for transmitting PHICH and a method of receiving PDCCH using the same are disclosed. The resource region for transmitting the PHICH can be specified by first information corresponding to the per-subframe PHICH number and second information corresponding to a duration of the PHICH within the subframe. The first information can be specified into a form resulting from multiplying a predetermined basic number by a specific constant. And, the specific constant can be transmitted via PBCH. Moreover, the second information can be acquired from the PBCH as well.

Abstract: In a mobile communication system using both a discontinuous transmission scheme and a compressed mode transmission scheme, if a preamble and/or a postamble of a channel including control information for transmitting a specific channel overlaps a compressed mode (CM) gap, an overall transmission unit is not transmitted or remaining signals of the transmission unit excluding the preamble and/or the postamble overlapping the CM gap are transmitted.

Abstract: The present invention provides for spreading a first signal using a plurality of spreading codes, multiplexing the first spread signal by code division multiplexing, transmitting the first multiplexed signal via a plurality of neighboring frequency resources of an OFDM symbol of a first antenna set, spreading a second signal using a plurality of spreading codes, multiplexing the second spread signal by code division multiplexing, transmitting the second multiplexed signal via a plurality of neighboring frequency resources of the OFDM symbol of the first antenna set, transmitting the first multiplexed signal via a plurality of neighboring frequency resources of an OFDM symbol of a second antenna set, and transmitting the second multiplexed signal via a plurality of neighboring frequency resources of the OFDM symbol of the second antenna set, wherein the first multiplexed signal is transmitted on frequency resources that neighbor frequency resources that the second multiplexed signal is transmitted on.

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: 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: A method of allocating channels in a user equipment is disclosed. In particular, a method of allocating a plurality of Dedicated Physical Channels (DPCHs) and Enhanced Dedicated Channels (E-DCHs) in a user equipment of a multicode transmission system. The method includes determining whether a High Speed Downlink Shared Channel (HS-DSCH) is configured for the user equipment (UE) and determining a number of codes used by the DPCH and the E-DCH. The method further includes allocating the DPCH and the E-DCH channels to an I branch or a Q branch based on the number of codes used by the DPCH and the E-DCH and the HS-DSCH configuration.

Abstract: The present invention provides for transmitting a spread signal in a mobile communication system. The present invention includes spreading a signal using a plurality of spreading codes, wherein the plurality of spreading codes have a spreading factor, multiplexing the spread signal by code division multiplexing, transmitting the multiplexed signal via a plurality of neighboring frequency resources of one OFDM symbol of a first antenna set, and transmitting the same multiplexed signal via a plurality of neighboring frequency resources of one OFDM symbol of a second antenna set.

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.