Abstract: A motor-driving apparatus for driving a motor having a plurality of windings respectively corresponding to a plurality of phases is provided. The motor-driving apparatus includes a first inverter having a plurality of first switching devices and connected to first ends of the plurality of windings and a second inverter having a plurality of second switching devices and connected to second ends of the plurality of windings. A third switching device is configured to selectively connect and disconnect points at which a number of turns of each of the windings is divided in a preset ratio. A controller is configured to adjust an on/off state of the first to third switching devices based on required output of the motor.

Abstract: 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.

Abstract: 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.