Abstract: A visible ray communication system and method that improve transmission rate and remove an influence of inter-color interference to improve the communication quality. A transmission apparatus included in the visible ray communication system allocates each carrier signal component of an OFDM signal, which is modulated into transmission information, to a plurality of LEDs of different colors. The information is added to a combination of a carrier frequency and an LED wavelength, when a carrier signal is allocated to an, in addition to each carrier signal being modulated into the information.

Abstract: Disclosed is a visible ray communication system including a transmission apparatus and a reception apparatus, wherein the transmission apparatus includes: a plurality of light emitting devices; an S/P converter for serial-to-parallel converting transmission data, thereby generating N data streams; a modulator for modulating the generated N data streams for respective carriers with a predetermined number of dimensions, thereby generating N modulated signals; a carrier signal multiplier for multiplying the generated N modulated signals by orthogonal N carrier signals, respectively, thereby generating N transmission signals; and a light emitting control unit for illuminating the plurality of light emitting devices according to the generated N transmission signals.

Abstract: Disclosed is a visible light communication system including a transmission device, including multiple light emitting units emitting light of different colors and mapping transmission data to a chromaticity point, calculating luminescence of each of the light emitting units, generating a preamble signal for channel matrix estimation, and emitting light based on the preamble signal and calculated luminescence amount. A reception device of the visible light communication system includes multiple light receiving units and estimates a channel matrix based on a corresponding optical signal when an optical signal corresponding to the preamble signal is received in each light receiving unit, compensates the optical signal corresponding to the chromaticity point for a propagation path based on the estimated channel matrix, detects a chromaticity point on the chromaticity coordinates based on a signal after the propagation path compensation, and demodulates the transmission data.

Abstract: A multi-input multi-output (MIMO) radio communication apparatus and method are provided. The MIMO apparatus includes a plurality of reception antennas each having a plurality of antenna patterns; a channel matrix estimation unit for estimating a channel matrix between a plurality of transmission antennas and the plurality of reception antennas; a channel capacity calculation unit for calculating a channel capacity corresponding to a combination of antenna patterns of the plurality of reception antennas by using the estimated channel matrix; and an antenna pattern control unit for changing the antenna patterns of the plurality of reception antennas to maximize the channel capacity. According to the MIMO radio communication apparatus and method, direction can be controlled adaptively to a propagation environment.