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: The disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). A feedback transmission method for a receiving device in a multiple input multiple output system according to one embodiment comprises: a step of measuring channel state information; a first quantization step of quantizing the channel state information using a first codebook; a second quantization step of quantizing the channel state information using second and third codebooks which are different from the first codebook; and a step of feeding back the channel state information on the basis of a selection result of one of the first and second quantization steps.

Abstract: The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). A channel information feedback in a wireless communication system and a method of a receiving node of a wireless communication system are provided. The method includes transmitting an indication representing an indexing rule for channel values and block-wise quantized channel information, and receiving beamformed signals mapped to an antenna based on the indexing rule.

Abstract: The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). A feedback transmission method for a receiving device in a multiple input multiple output system according to one embodiment comprises: a step of measuring channel state information; a first quantization step of quantizing the channel state information using a first codebook; a second quantization step of quantizing the channel state information using second and third codebooks which are different from the first codebook; and a step of feeding back the channel state information on the basis of a selection result of one of the first and second quantization steps.

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: 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: 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 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: The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). A channel information feedback in a wireless communication system and a method of a receiving node of a wireless communication system are provided. The method includes transmitting an indication representing an indexing rule for channel values and block-wise quantized channel information, and receiving beamformed signals mapped to an antenna based on the indexing rule.

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: 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.

Abstract: A multiple-input multiple-output (MIMO) communication system and method using a codebook, are provided. A transmitter and at least one receiver included in the MIMO communication system may use at least one codebook from among a plurality of codebooks. Codeword matrices included in one of the codebooks may correspond to vectors included in a block diagonal matrix, and another codebook may be configured by rotating the vectors. The codeword matrices of the remaining codebooks may include the rotated vectors and random vectors.

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: 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 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: Provided is a method of generating an adaptive codebook and a multiple input multiple output (MIMO) communication system using the adaptive codebook. A transmitter and a receiver may generate, from a base codebook based on a matrix associated with statistics of a channel matrix, the adaptive codebook maintaining a unitary characteristic. The transmitter may perform scheduling, transmit filter design, and precoding using adaptive codebook based feedback information.

Abstract: Provided is a multiple-input multiple-output (MIMO) communication system that may provide a plurality of feedback modes. A receiver may feed back, to a transmitter, a base codeword indicator indicating one of base codewords included in the base codebook, a differential codeword indicator indicating one of differential codewords included in the differential codebook, and/or a correlation codeword indicator indicating one of correlation codewords included in the correlation codebook. The transmitter may generate a precoding matrix using at least one of the base codeword indicator, the differential codeword indicator, and the correlation codeword indicator.

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: 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: 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.