Abstract: A beamforming transmission device includes a control unit, at least one radio frequency unit, and at least one signal transmission unit. The control unit is configured to receive a radio frequency signal and channel state information of at least two pieces of user equipment, and to generate a control signal according to the radio frequency signal and the channel state information of the at least two pieces of user equipment. The radio frequency unit is coupled to the control unit. The radio frequency unit is configured to receive the control signal and generate a beamforming signal according to the control signal. The signal transmission unit is coupled to the radio frequency unit. The signal transmission unit is configured to transmit the beamforming signal to the at least two pieces of user equipment.

Abstract: A millimeter wave channel estimation method comprises sending signals through a millimeter wave channel according to a first beamforming matrix, performing a channel estimation on the millimeter wave to generate a first measured matrix, and estimating and obtaining at least one angle of departure of the millimeter wave channel according to the first measured matrix and an angle compressive sensing matrix. The first beamforming matrix comprises a plurality of first beamforming vectors, and the first beamforming vectors respectively corresponds to a plurality of first beamforming patterns. The first measured matrix comprises a plurality of first measured parameters respectively corresponding to the first beamforming vectors.

Abstract: A millimeter wave channel estimation method comprises sending signals through a millimeter wave channel according to a first beamforming matrix, performing a channel estimation on the millimeter wave to generate a first measured matrix, and estimating and obtaining at least one angle of departure of the millimeter wave channel according to the first measured matrix and an angle compressive sensing matrix. The first beamforming matrix comprises a plurality of first beamforming vectors, and the first beamforming vectors respectively corresponds to a plurality of first beamforming patterns. The first measured matrix comprises a plurality of first measured parameters respectively corresponding to the first beamforming vectors.

Abstract: A method for manufacturing a polycrystalline silicon ingot includes steps of: a) melting a silicon material in a container disposed in a thermal field to form a molten silicon; b) controlling the thermal field to provide heat to the molten silicon from above the container and to solidify a portion of the molten silicon contacting a base part and at least a portion of a wall part proximate to the base part of the container to form a solid silicon crystalline isolation layer; and c) controlling the thermal field to continuously provide heat to the rest of the molten silicon from above the container and to solidify the rest of the molten silicon gradually from a bottom to a top of the rest of the molten silicon to form a polycrystalline silicon ingot.

Abstract: A method for manufacturing a polycrystalline silicon ingot includes steps of: a) melting a silicon material in a container disposed in a thermal field to form a molten silicon; b) controlling the thermal field to provide heat to the molten silicon from above the container and to solidify a portion of the molten silicon contacting a base part and at least a portion of a wall part proximate to the base part of the container to form a solid silicon crystalline isolation layer; and c) controlling the thermal field to continuously provide heat to the rest of the molten silicon from above the container and to solidify the rest of the molten silicon gradually from a bottom to a top of the rest of the molten silicon to form a polycrystalline silicon ingot.

Abstract: A method for manufacturing a polycrystalline silicon ingot includes steps of: a) melting a silicon material in a container disposed in a thermal field to form a molten silicon; b) controlling the thermal field to provide heat to the molten silicon from above the container and to solidify a portion of the molten silicon contacting a base part and at least a portion of a wall part proximate to the base part of the container to form a solid silicon crystalline isolation layer; and c) controlling the thermal field to continuously provide heat to the rest of the molten silicon from above the container and to solidify the rest of the molten silicon gradually from a bottom to a top of the rest of the molten silicon to form a polycrystalline silicon ingot.