Abstract: Provided is method for generating a precoder in a Multi User Multiple Input and Multiple Output (MU MIMO) communication system. The method involves receiving channel information and quality information of a channel from a plurality of stations. It is determined whether a first condition is satisfied on the basis of the received information, if so, a type of matrix inversion is selected from among a plurality of matrix inversion types for precoding. It is determined whether a second condition is satisfied on the basis of the provided information, and a type of decomposition from a plurality of decomposition types for precoding is selected if the second condition is satisfied. A precoder is generated on the basis of the selected result.

Abstract: An operation method of a transmitting device such as an access point providing wireless communication includes receiving a feedback of channel response information from an external communication device, generating a beam steering matrix based on the channel response information, generating a power allocation matrix based on an average SNR for each of a plurality of streams included in the channel response information, and performing beamforming on the external communication device based on the generated power allocation matrix and the generated beam steering matrix. The channel response information is a compressed beamforming feedback of multiple input multiple output single user beamforming. A first power allocated to a first stream, of which an average SNR is a first value, from among the plurality of streams is larger than a second power allocated to a second stream, of which an average SNR is a second value greater than the first value.

Abstract: Provided is method for generating a precoder in a Multi User Multiple Input and Multiple Output (MU MIMO) communication system. The method involves receiving channel information and quality information of a channel from a plurality of stations. It is determined whether a first condition is satisfied on the basis of the received information, if so, a type of matrix inversion is selected from among a plurality of matrix inversion types for precoding. It is determined whether a second condition is satisfied on the basis of the provided information, and a type of decomposition from a plurality of decomposition types for precoding is selected if the second condition is satisfied. A precoder is generated on the basis of the selected result.

Abstract: A beam transmitting device improves performance of a communication channel. The beam transmitting device includes a controller configured to transmit a null data packet (NDP) and receive channel information; and a smoothing circuit configured to smooth a plurality of beamforming vectors in the channel information. The smoothing circuit includes a weight calculator configured to calculate a common phase factor using two adjacent beamforming vectors among the plurality of beamforming vectors, and a moving average filter configured to perform the smoothing using the common phase factor.

Abstract: Provided is method for generating precoder in a Multi User Multiple Input and Multiple Output (MU MIMO) communication system. The method involves receiving channel information and quality information of a channel from a plurality of stations. It is determined whether a first condition is satisfied on the basis of the received information, if so, a type of matrix inversion is selected from among a plurality of matrix inversion types for precoding. It is determined whether a second condition is satisfied on the basis of the provided information, and a type of decomposition from a plurality of decomposition types for precoding is selected if the second condition is satisfied. A precoder is generated on the basis of the selected result.

Abstract: An operation method of a transmitting device such as an access point providing wireless communication includes receiving a feedback of channel response information from an external communication device, generating a beam steering matrix based on the channel response information, generating a power allocation matrix based on an average SNR for each of a plurality of streams included in the channel response information, and performing beamforming on the external communication device based on the generated power allocation matrix and the generated beam steering matrix. The channel response information is a compressed beamforming feedback of multiple input multiple output single user beamforming. A first power allocated to a first stream, of which an average SNR is a first value, from among the plurality of streams is larger than a second power allocated to a second stream, of which an average SNR is a second value greater than the first value.

Abstract: A beam transmitting device improves performance of a communication channel. The beam transmitting device includes a controller configured to transmit a null data packet (NDP) and receive channel information; and a smoothing circuit configured to smooth a plurality of beamforming vectors in the channel information. The smoothing circuit includes a weight calculator configured to calculate a common phase factor using two adjacent beamforming vectors among the plurality of beamforming vectors, and a moving average filter configured to perform the smoothing using the common phase factor.

Abstract: Provided is method for generating precoder in a Multi User Multiple Input and Multiple Output (MU MIMO) communication system. The method involves receiving channel information and quality information of a channel from a plurality of stations. It is determined whether a first condition is satisfied on the basis of the received information, if so, a type of matrix inversion is selected from among a plurality of matrix inversion types for precoding. It is determined whether a second condition is satisfied on the basis of the provided information, and a type of decomposition from a plurality of decomposition types for precoding is selected if the second condition is satisfied. A precoder is generated on the basis of the selected result.

Abstract: A method for wireless communications includes: receiving a sounding packet from an access point; determining a rank of a channel matrix corresponding to a communications channel; and when the rank of the channel matrix is a full rank: selecting at least one of a plurality of pieces of codebook information previously stored in a memory, as beamforming information, transmitting the beamforming information to the access point, and applying channel smoothing to a communications channel provided by the access point.

Abstract: A method for wireless communications includes: receiving a sounding packet from an access point; determining a rank of a channel matrix corresponding to a communications channel; and when the rank of the channel matrix is a full rank: selecting at least one of a plurality of pieces of codebook information previously stored in a memory, as beamforming information, transmitting the beamforming information to the access point, and applying channel smoothing to a communications channel provided by the access point.

Abstract: Methods of operating a wireless communication device for adaptive beamforming of a base station according to a state of a channel are provided. The methods include receiving a sounding packet from the base station through the channel; obtaining channel quality about the channel, using the sounding packet; selecting a feedback mode out of a plurality of feedback modes based on the channel quality; generating a matrix to be a basis of the adaptive beamforming, based on the selected feedback mode; and transmitting channel state information including information on the matrix to the base station.

Abstract: Methods of operating a wireless communication device for adaptive beamforming of a base station according to a state of a channel are provided. The methods include receiving a sounding packet from the base station through the channel; obtaining channel quality about the channel, using the sounding packet; selecting a feedback mode out of a plurality of feedback modes based on the channel quality; generating a matrix to be a basis of the adaptive beamforming, based on the selected feedback mode; and transmitting channel state information including information on the matrix to the base station.