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: 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: 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: The present invention relates to a 5th-generation (5G) or pre-5G communication system which is provided for supporting a higher data transfer rate after a 4th-generation (4G) communication system such as a long term evolution (LTE). The present invention provides a method for selecting, by an access point (AP), a beam in a communication system supporting a beamforming scheme, the method comprising: a step of transmitting information which indicates whether or not a duplicated beacon transmission interval (BTI) is operated; and a step of performing a transmit sector sweep (TXSS) process at least twice during the duplicated BTI.

Abstract: The present invention relates to a 5th-generation (5G) or pre-5G communication system which is provided for supporting a higher data transfer rate after a 4th-generation (4G) communication system such as a long term evolution (LTE). The present invention provides a method for selecting, by an access point (AP), a beam in a communication system supporting a beamforming scheme, the method comprising: a step of transmitting information which indicates whether or not a duplicated beacon transmission interval (BTI) is operated; and a step of performing a transmit sector sweep (TXSS) process at least twice during the duplicated BTI.

Abstract: A display device includes a lamp unit, a dimming signal controller, and an inverter device. The dimming signal controller receives a lamp brightness signal and an external environment illumination signal, selects the lamp brightness signal or a signal based on the received external environment illumination signal, and outputs the selected signal as a dimming signal. The inverter device may operate to control brightness of the lamp unit based on the dimming signal.

Abstract: A quenching apparatus for a reactor is disclosed. The quenching apparatus includes a quenching unit (31) and a mixing unit (41). The quenching unit includes fluid distribution pipes (33) which branch off from a central portion of the quenching unit in radial directions and eject quenching fluid, and one or more first fluid outlets (35) which are formed through the bottom of the quenching unit. The mixing unit includes inclined baffles (43), one or more partitions (42) and a second fluid outlet (45). The inclined baffles are respectively disposed under the first fluid outlets. The partitions partition a space between inner and outer sidewalls of the mixing unit into a plurality of separated spaces in which the inclined baffles are respectively disposed. Fluid guided by the inclined baffles and the partitions is discharged out of the mixing unit through the second fluid outlet.

Abstract: A full bridge switching circuit includes a converter circuit including first and second converters. The first converter includes a first transformer and a first switching element part to control the first transformer in response to a first switching signal. The second converter includes a second transformer and a second switching element part to control the second transformer in response to a second switching signal. The first and second transformers are controlled by the first and second switching element parts to output first and second feedback signals, respectively. The full bridge switching circuit further includes a third switching element part having a third switching input connected to the first and second transformers, and an IC circuit to generate an OR signal by an OR operation of a first control signal generated from the first feedback signal and a second control signal generated from the second feedback signal.

Abstract: A control circuit of a switching power supply for supplying a drive voltage to a light emitting element is provided. The control circuit includes a pulse width modulator which generates a pulse signal whose duty ratio is adjusted such that a detection voltage corresponding to an output voltage of the switching power supply is equal to a predetermined reference voltage, a driver which drives a switching element of the switching power supply based on the pulse signal, and a standby control unit which stops driving of the switching element once a predetermined time has passed after a standby signal steps down to a level indicating a standby state, and to shut down the control circuit and a current source.

Abstract: A display device includes a lamp unit, a dimming signal controller, and an inverter device. The dimming signal controller receives a lamp brightness signal and an external environment illumination signal, selects the lamp brightness signal or a signal based on the received external environment illumination signal, and outputs the selected signal as a dimming signal. The inverter device may operate to control brightness of the lamp unit based on the dimming signal.

Abstract: A full bridge switching circuit includes a converter circuit including first and second converters. The first converter includes a first transformer and a first switching element part to control the first transformer in response to a first switching signal. The second converter includes a second transformer and a second switching element part to control the second transformer in response to a second switching signal. The first and second transformers are controlled by the first and second switching element parts to output first and second feedback signals, respectively. The full bridge switching circuit further includes a third switching element part having a third switching input connected to the first and second transformers, and an IC circuit to generate an OR signal by an OR operation of a first control signal generated from the first feedback signal and a second control signal generated from the second feedback signal.

Abstract: A quenching apparatus for a reactor is disclosed. The quenching apparatus includes a quenching unit (31) and a mixing unit (41). The quenching unit includes fluid distribution pipes (33) which branch off from a central portion of the quenching unit in radial directions and eject quenching fluid, and one or more first fluid outlets (35) which are formed through the bottom of the quenching unit. The mixing unit includes inclined baffles (43), one or more partitions (42) and a second fluid outlet (45). The inclined baffles are respectively disposed under the first fluid outlets. The partitions partition a space between inner and outer sidewalls of the mixing unit into a plurality of separated spaces in which the inclined baffles are respectively disposed. Fluid guided by the inclined baffles and the partitions is discharged out of the mixing unit through the second fluid outlet.

Abstract: A control circuit of a switching power supply for supplying a drive voltage to a light emitting element is provided. The control circuit includes a pulse width modulator which generates a pulse signal whose duty ratio is adjusted such that a detection voltage corresponding to an output voltage of the switching power supply is equal to a predetermined reference voltage, a driver which drives a switching element of the switching power supply based on the pulse signal, and a standby control unit which stops driving of the switching element once a predetermined time has passed after a standby signal steps down to a level indicating a standby state, and to shut down the control circuit and a current source.