Abstract: This invention provides methods of beam-indexed spatial modulation (BISM) for multiple-input and multiple-output (MIMO) technology. It does not only enhance the efficiency of MIMO using, but also address the compatibility problems in Spatial Modulation (SM-MIMO) and Orthogonal Frequency Division Multiplexing Index Modulation (OFDM-IM). Furthermore, the BISM improves the speed limitation problem and spectral efficiency issue in the current spatial modulation architectures.

Abstract: This invention provides methods of beam-indexed spatial modulation (BISM) for multiple-input and multiple-output (MIMO) technology. It does not only enhance the efficiency of MIMO using, but also address the compatibility problems in Spatial Modulation (SM-MIMO) and Orthogonal Frequency Division Multiplexing Index Modulation (OFDM-IM). Furthermore, the BISM improves the speed limitation problem and spectral efficiency issue in the current spatial modulation architectures.

Abstract: An exemplary projector includes a main body, a lens at a front of the main body and a lens barrier module positioned at the front of the main body for covering the lens when the projector is not in use or exposing the lens when the projector is in use. The lens barrier module includes a front bezel defining an opening aligned with the lens, a lens frame secured to a rear side of the front bezel and separated from the front bezel, and a lens cover slidably received between the front bezel and the lens frame. The lens frame defines an aperture aligned with the opening. The lens cover is positioned in a manner to selectively cover or uncover the lens.

Abstract: A height adjustment apparatus for a projector includes a lifting member and an engaging member. The projector includes a front wall and a bottom wall substantially perpendicular to the front wall. The front wall defines a sliding slot extending along a direction substantially perpendicular to the bottom wall and an opening extending through the bottom wall of the sliding slot. The lifting member includes a lifting portion slidable along the sliding slot, the lifting portion includes two side walls, each side wall includes a toothed surface The engaging member is corresponding to the opening, the engaging member includes a main body and two deformable arms extending into the sliding slot. Each deformable arm includes an engaging portion for engaging with one of the toothed surfaces.

Abstract: An exemplary projector includes a main body, a lens at a front of the main body and a lens barrier module positioned at the front of the main body for covering the lens when the projector is not in use or exposing the lens when the projector is in use. The lens barrier module includes a front bezel defining an opening aligned with the lens, a lens frame secured to a rear side of the front bezel and separated from the front bezel, and a lens cover slidably received between the front bezel and the lens frame. The lens frame defines an aperture aligned with the opening. The lens cover is positioned in a manner to selectively cover or uncover the lens.