Sejong University

Lg Electronics Inc.

Ji Hye Oh

Hyoung Kyu Song

In Ho Lee

Won Seok Lee

Jae Woong Jeong

Young Hwan You

Thanh Binh Nguyen

Ji Sung Jung

Beom Sik Shin

Min A Kim

Abrar Shakil Sejan Mohammad

Yeong Rong Lee

The present disclosure relates to a method for feeding back reliable downlink channel state information from a receiver to a transmitter in a multi-user massive MIMO system based on a reconfigurable intelligent surface, and more particularly, to a method for the receiver to transform acquired downlink channel state information into downlink channel state information in an angle domain and compress the downlink channel state information through a compressed-sensing scheme, and then feed the compressed result back to the transmitter, and for the transmitter to acquire the reliable downlink channel state information through a recovery algorithm. According to the present disclosure, the downlink channel state information is compressed according to a compression and recovery algorithm in an mmWave environment, and only a codeword index suitable for the compressed result is fed back to the transmitter to obtain the effect of reduction in feedback overhead in the entire communication system.

Channel state information feedback method in reconfigurable intelligent surface-based massive MIMO system

The present inventive concept relates to a method for designing an optimal analog precoder for improving frequency spectrum efficiency in a millimeter wave-based multi-user massive MIMO-based hybrid beamforming system and a hybrid beamforming system applying the same, and more specifically, to a method for designing an optimal analog precoder using an approximation technique and an iterative optimization algorithm, and a hybrid beamforming system to which the same is applied.

Millimeter wave-based multi-user massive MIMO-based hybrid beamforming system and analog precoder matrix acquisition method applied thereto

Disclosed is a method of operating an air purifier by executing an artificial intelligence (AI) algorithm and/or a machine learning algorithm in a fifth generation (5G) environment connected for the Internet of Things. A method for operating an air purifier comprises determining whether an indoor situation is a situation in which protection of a filter is necessary based on sensor information from at least one sensor, in response to a determination that the indoor situation is the situation in which protection of the filter is necessary, suspending an air purifying function, and operating one or more ventilation devices. According to the present disclosure, it is possible to protect the air purifier from a situation in which a life of the filter of the air purifier can be drastically shortened.

Air purifier and operating method of the same

Growing community of inventors

Seoul, South Korea

Ji Hye Oh