Abstract: Provided are a method and device for low-complexity feedback in a multiuser and multipoint cooperative communication system. The base station in the multiuser and multipoint cooperative communication system transmits a feedback stop signal to a terminal in order for the terminal receiving the feedback stop signal to stop feedback for a predetermined period. The terminal receiving the feedback stop signal stops the feedback of channel information for a period indicated by the feedback stop signal.

Abstract: A system and method for transmitting signals via multi-input single-output (MISO) broadcast channel with imperfect channel state information at the transmitter (CSIT). The transmitter receives each CSI of from the plural receivers, determines a transmit power and a transmission rate based on the CSI qualities of the plural receivers calculated from the each CSI, and transmits the signal using the transmit power and the transmission rate. The signal comprises a user specific message, a first common message and a second common message to compensate imperfect CSIT.

Abstract: A transmitter and a receiver of a multiple input multiple output (MIMO) communication system may use two codebooks to share channel information. When the transmitter uses eight transmit antennas, two codebooks may be defined. When the receiver generates two precoding matrix indicators from two codebooks, a combination of the two precoding matrix indicators may indicate a single precoding matrix. Precoding matrix candidates may also be defined.

Abstract: A control information transmission and reception method based on a spatial-multiplexing gain, are provided. The control information may be transmitted by obtaining the spatial-multiplexing gain using an E-PDCCH region, and thus, a transmission efficiency of the control information may be improved. The common control information used for decoding the E-PDCCH may be transmitted via a PDCCH, and thus, a base station supporting both a general terminal and an enhanced terminal may effectively transmit the control information. Information associated with an indicator indicating whether the E-PDCCH is to be used during a subsequent resource allocation period may be transmitted, and thus, whether decoding with respect to the E-PDCCH is to be performed during the subsequent allocation period may be determined.

Abstract: The embodiment of the disclosure discloses a base station, a mobile station and a method thereof. The base station includes a processor and a transceiver. The processor determines a first subgroup to which a first mobile station belongs, wherein the first mobile station is one of a plurality of mobile stations, the plurality of mobile stations are grouped into G groups based on spatial correlation, the mobile stations in each of the G groups are further grouped into S subgroups based on polarization, the mobile stations in a same subgroup have a same polarization and the mobile stations in different subgroups have different polarizations. The transceiver communicates with the first mobile station according to the polarization of the first subgroup. The embodiments of the disclosure utilize polarization jointly with the spatial correlation in dual structured procoding so that feedback overhead can be reduced.

Abstract: A system and method for transmitting signals via multi-input single-output (MISO) broadcast channel with imperfect channel state information at the transmitter (CSIT). The transmitter receives each CSI of from the plural receivers, determines a transmit power and a transmission rate based on the CSI qualities of the plural receivers calculated from the each CSI, and transmits the signal using the transmit power and the transmission rate. The signal comprises a user specific message, a first common message and a second common message to compensate imperfect CSIT.

Abstract: A method for estimating a channel in a wireless communication system in which a plurality of terminals and a base station communicate with each other, according to one embodiment of the present invention, comprises the steps of: receiving reference signals transmitted through a plurality of slots; and estimating a channel by using the reference signals. Here, for the channel estimation, the number of reference signals received through at least one slot among the plurality of slots is different from the number of reference signals received through the other slots.

Abstract: A method and an apparatus for use in a multiuser radio communication system for transmitting and receiving a signal in a Multiple Input and Multiple Output (MIMO) broadcast channel with an imperfect Channel State Information at the Transmitter (CSIT) are provided. The signal transmission/reception method includes receiving CSI from each of a plurality of receivers, determining a transmit power and a transmission rate based on the CSI qualities of the plurality of receivers calculated from the CSI from each of the plurality of receivers, and transmitting the signal using the transmit power and the transmission rate. The present disclosure is capable of maximizing system throughput in wireless communication system.

Abstract: The present invention relates to a method and apparatus for interference alignment in a wireless communication system.

Abstract: A method for transmitting and receiving a codebook subset restriction bitmap is provided. The Codebook Subset Restriction (CSR) bitmap transmission method of an evolved Node B (eNB) in transmission mode 9 for communication with 8 antenna ports includes generating a CSR bitmap including bits corresponding to restricted precoding matrix indicators and rank indicators that are not allowed for reporting and transmitting the CSR bitmap to a User Equipment (UE). The CSR bitmap comprises 53 bits corresponding to a first codebook and 56 bits corresponding to a second codebook, the 53 bits corresponding to a first codebook comprise 16, 16, 4, 4, 4, 4, and 1 bits for layers 1, 2, 3, 4, 5, 6, 7, and 8, respectively, and the 56 bits corresponding to a second codebook comprise 16, 16, 16 and 8 bits for layers 1, 2, 3, and 4, respectively.

Abstract: Provided is a multiple input multiple output (MIMO) communication system using a codebook. A transmitter and a receiver included in the MIMO communication system may generate a codebook having a different size for each eigenvector of a channel matrix or a channel covariance matrix, based on eigenvalues of the channel matrix or the channel covariance matrix.

Abstract: A method for transmitting and receiving a codebook subset restriction bitmap is provided. The Codebook Subset Restriction (CSR) bitmap transmission method of an evolved Node B (eNB) in transmission mode 9 for communication with 8 antenna ports includes generating a CSR bitmap including bits corresponding to restricted precoding matrix indicators and rank indicators that are not allowed for reporting and transmitting the CSR bitmap to a User Equipment (UE). The CSR bitmap comprises 53 bits corresponding to a first codebook and 56 bits corresponding to a second codebook, the 53 bits corresponding to a first codebook comprise 16, 16, 4, 4, 4, 4, and 1 bits for layers 1, 2, 3, 4, 5, 6, 7, and 8, respectively, and the 56 bits corresponding to a second codebook comprise 16, 16, 16 and 8 bits for layers 1, 2, 3, and 4, respectively.

Abstract: A method for transmitting and receiving a codebook subset restriction bitmap is provided. The Codebook Subset Restriction (CSR) bitmap transmission method of an evolved Node B (eNB) in transmission mode 9 for communication with 8 antenna ports includes generating a CSR bitmap including bits corresponding to restricted precoding matrix indicators and rank indicators that are not allowed for reporting and transmitting the CSR bitmap to a User Equipment (UE). The CSR bitmap comprises 53 bits corresponding to a first codebook and 56 bits corresponding to a second codebook, the 53 bits corresponding to a first codebook comprise 16, 16, 4, 4, 4, 4, and 1 bits for layers 1, 2, 3, 4, 5, 6, 7, and 8, respectively, and the 56 bits corresponding to a second codebook comprise 16, 16, 16 and 8 bits for layers 1, 2, 3, and 4, respectively.

Abstract: A method for transmitting and receiving a codebook subset restriction bitmap is provided. The Codebook Subset Restriction (CSR) bitmap transmission method of an evolved Node B (eNB) in transmission mode 9 for communication with 8 antenna ports includes generating a CSR bitmap including bits corresponding to restricted precoding matrix indicators and rank indicators that are not allowed for reporting and transmitting the CSR bitmap to a User Equipment (UE). The CSR bitmap comprises 53 bits corresponding to a first codebook and 56 bits corresponding to a second codebook, the 53 bits corresponding to a first codebook comprise 16, 16, 4, 4, 4, 4, and 1 bits for layers 1, 2, 3, 4, 5, 6, 7, and 8, respectively, and the 56 bits corresponding to a second codebook comprise 16, 16, 16 and 8 bits for layers 1, 2, 3, and 4, respectively.

Abstract: Provided is a multiple input multiple output (MIMO) communication method and system that may exchange information associated with a coordinated rank for a neighbor cell. In a MIMO communication system, a target terminal may feed back the information associated with the coordinated rank to a serving base station, and the serving base station may exchange the information associated with the coordinated rank with the neighbor base station. The serving base station may perform precoding based on the exchanged information associated with the coordinated rank.

Abstract: A method and an apparatus for use in a multiuser radio communication system for transmitting and receiving a signal in a Multiple Input and Multiple Output (MIMO) broadcast channel with an imperfect Channel State Information at the Transmitter (CSIT) are provided. The signal transmission/reception method includes receiving CSI from each of a plurality of receivers, determining a transmit power and a transmission rate based on the CSI qualities of the plurality of receivers calculated from the CSI from each of the plurality of receivers, and transmitting the signal using the transmit power and the transmission rate. The present disclosure is capable of maximizing system throughput in wireless communication system.

Abstract: Provided is a coordinated communication method and apparatus that may perform coordinated communication based on long-term channel information, for each sub-band. Base stations may exchange scheduling information of each sub-band with each other to determine a priority among the base stations, and may perform rescheduling for each sub-band based on the determined priority. The base stations may obtain the long-term channel information, and thus may reduce overhead occurring with exchanging of information between a base station and a terminal or between base stations, and may decrease damage due to a delay of channel information associated with a terminal.

Abstract: Provided is a feedback method and apparatus in a multiple-input multiple-output (MIMO) communication system. A terminal may determine a preferred pre-coding matrix for a neighboring terminal, based on a reference rank determined by a base station and a preferred pre-coding matrix of the terminal. The terminal may calculate a channel quality indicator (CQI) based on the preferred precoding matrix for the neighboring terminal, and may feed the CQI back to the base station.

Abstract: A method for transmitting and receiving a codebook subset restriction bitmap is provided. The Codebook Subset Restriction (CSR) bitmap transmission method of an evolved Node B (eNB) in transmission mode 9 for communication with 8 antenna ports includes generating a CSR bitmap including bits corresponding to restricted precoding matrix indicators and rank indicators that are not allowed for reporting and transmitting the CSR bitmap to a User Equipment (UE). The CSR bitmap comprises 53 bits corresponding to a first codebook and 56 bits corresponding to a second codebook, the 53 bits corresponding to a first codebook comprise 16, 16, 4, 4, 4, 4, and 1 bits for layers 1, 2, 3, 4, 5, 6, 7, and 8, respectively, and the 56 bits corresponding to a second codebook comprise 16, 16, 16 and 8 bits for layers 1, 2, 3, and 4, respectively.

Abstract: Provided is a channel state information (CSI) sharing method and apparatus in a Multiple User Multiple Input Multiple Output (MU-MIMO) environment. Each node may use network-coding to reduce overhead necessary for sharing CSI between all nodes in the MU-MIMO environment. A transmitter may dynamically select, based on the CSI between receivers, a path used for transmitting data to each receiver and a receiver to be used as a relay based on the global CSI. A decoding performance may be improved based on the CSI between the transmitter and the receivers.