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.

Abstract: A multiple input multiple output (MIMO) communication method using a codebook is provided. The MIMO communication method may use one or more codebooks and the codebooks may change according to a transmission rank, a channel state of a user terminal, and/or a number of feedback bits. The one or more codebooks may be adaptively updated according to a time correlation coefficient of a channel.

Abstract: In a multi-user multiple input multiple output (MIMO) communication, each of receivers may use a different channel codebook and a transmitter may determine beamforming vectors using a beamforming codebook corresponding to each of the receivers.

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: An apparatus and method of generating a codebook. The codebook generation apparatus includes a matrix extender to generate a candidate matrix set by multiplying a base matrix and at least one diagonal matrix, wherein the at least one diagonal matrix includes elements of a constrained set as diagonal elements; and a codebook generator to generate the codebook where a minimum distance between the elements is maximized, based on the candidate matrix set. According to aspects of the present invention, it is possible to provide a precoding codebook that can reduce an amount of feedback from a terminal.

Abstract: Communication between a base station with multiple transmission antennas and a mobile station is provided. The base station and the mobile station may recognize or estimate, respectively, a channel between the base station and the mobile station, and update a previous codebook with a new codebook based on a variation of the channel. In this instance, the mobile station may provide feedback information to the base station using the new codebook, and the base station may generate a transmission signal for the mobile station using the new codebook and the feedback information.

Abstract: A transmission/reception apparatus and a method thereof in a codebook-based multiple antenna system is provided. In a transmission method in a codebook-based Multiple Input Multiple Output (MIMO) system, feedback information is received from a receiver. A downlink Open-Loop Single User MIMO (OL SU-MIMO) codebook subset is determined within a base cookbook based on the feedback information. At least one data stream is transmitted via at least one antenna using the determined downlink OL SU-MIMO codebook subset.

Abstract: A multiple input multiple output (MIMO) communication system using an explicit feedback is provided. In the MIMO communication system using the explicit feedback, a receiver may generate an explicit feedback vector by calculating an explicit channel matrix, and by vectorizing the explicit channel matrix or an explicit channel matrix processed using a predefined function. Feedback information generated based on the explicit feedback vector may be provided to a transmitter. The transmitter may reconfigure the explicit channel matrix or the processed explicit channel matrix based on the feedback information. The transmitter and the receiver may share the explicit channel matrix or the processed explicit channel matrix using an adaptively transformed codebook.

Abstract: A method for operating a Mobile Station (MS) in a Multiple Input Multiple Output (MIMO) wireless communication system is provided. The method includes measuring channel quality for a serving Base Station (BS), if the channel quality is less than a threshold, measuring interference power from one or more neighbor BSs, determining a Precoding Matrix Index (PMI) and a priority metric for each neighbor BS, and feeding back at least one of the PMI, a PMI type indicator, the priority metric, and the channel quality to the serving BS.

Abstract: A rotating reference codebook used in a multiple input multiple output (MIMO) communication system is provided. The reference codebook includes codewords from a discrete Fourier transform (DFT) codebook. A base station and a terminal may calculate a rotation matrix based on a previous preferred codeword and a random codeword among codewords included in the DFT codebook. A reference codebook may be rotated using the rotation matrix and may be transformed to a new codebook. The reference codebook may include codewords of a polar cap codebook and the codewords of the DFT codebook. Even though the codewords of the DFT codebook are rotated, the codewords of the DFT codebook may remain in the new codebook as elements of the DFT codebook.

Abstract: A multiple input multiple output (MIMO) communication system and communication method of configuring a codebook are provided. A channel may be formed between a transmitter and a receiver, and a cross-polarization discrimination value (XPD) may be detected. The XPD may vary based on a location of the transmitter and the receiver, a mobility thereof, or a peripheral environment, among other factors. The codebook may be configured based on the XPD.

Abstract: A multiple input multiple output (MIMO) communication method using a codebook is provided. The MIMO communication method may use one or more codebooks and the codebooks may change according to a transmission rank, a channel state of a user terminal, and/or a number of feedback bits. The one or more codebooks may be adaptively updated according to a time correlation coefficient of a channel.

Abstract: A subscriber station is provided. The subscriber station comprises a receiver configured to listen for downlink control information for coordinated multipoint (CoMP) joint transmission only from an anchor cell, and to receive the downlink control information for CoMP joint transmission from the anchor cell.

Abstract: A terminal and method for generating a codebook for a multiple-input multiple-output (MIMO) system is provided. The codebook generation includes: assigning a single-polarized precoding matrix to diagonal blocks among a plurality of blocks arranged in a block diagonal format in which a number of diagonal blocks corresponds to a number of polarization directions of transmitting antennas; and assigning a zero matrix to remaining blocks excluding the diagonal blocks.

Abstract: A multiple input multiple output (MIMO) communication method using a codebook is provided. The MIMO communication method may use one or more codebooks and the codebooks may change according to a transmission rank, a channel state of a user terminal, and/or a number of feedback bits.

Abstract: A method provides mixed analog/digital beamforming by a transmitter in a mobile communication system. The method includes converting a modulation symbol into a parallel symbol stream, performing digital beamforming on the parallel symbol stream, performing an IFFT operation on the digital-beamformed parallel symbol stream to generate a time-domain symbol, converting the IFFT-operated time-domain symbol into a serial time-domain symbol, inserting a CP into the serial time-domain symbol, performing a DAC operation on the CP-inserted symbol to generate an analog signal, and performing analog beamforming by multiplying the analog signal by the analog beamforming precoder optimized for the first subcarrier transmitted through at least one RF channel.

Abstract: A method of generating a codebook for a multiple-input multiple-output (MIMO) system is provided. The codebook generation method includes: assigning a single-polarized precoding matrix to diagonal blocks among a plurality of blocks arranged in a block diagonal format in which a number of diagonal blocks corresponds to a number of polarization directions of transmitting antennas; and assigning a zero matrix to remaining blocks excluding the diagonal blocks.

Abstract: A method and system for resource allocation for data and control channels is provided. A downlink transmission method of a base station in a the system includes determining, by the base station, whether resources for a terminal are restricted; determining a sub-set of resource blocks for the terminal from among all resource blocks, if the resources for the terminal are restricted; transmitting information about the sub-set of the resource blocks to the terminal; and allocating a first sub-sub-set of the sub-set of the resource blocks for control channel transmission, and a second sub-sub-set of the sub-set of the resource blocks for data channel transmission.

Abstract: Provided are a beamforming vector determining method and an apparatus which may compute a normalization factor of each of a plurality of terminals by normalizing a predetermined reference value using noise power occurring in each of the terminals. A leakage channel of each of the terminals may be estimated, and a beamforming vector for each of the terminals may be determined with respect to a plurality of base stations based on the leakage channel of each of the terminals.

Abstract: Provided is an uplink feedback channel allocation method and apparatus used to feedback data to indicate whether data packets corresponding an enhanced physical downlink control channel (E-PDCCH) were successfully decoded. A terminal may use an additional resource area of an uplink feedback channel or may use an empty resource area of the uplink feedback channel to which feedback information of a data packet corresponding to a physical downlink control channel (PDCCH) is not allocated, to perform feedback.