Abstract: Disclosed is an apparatus for measuring a bit error rate (BER) in an orthogonal frequency division multiplexing (OFDM) communication system. A transmitter includes a pilot pattern inserter for inserting a first reference pilot pattern in subchannels of input data, and an OFDM modulator for OFDM-modulating the reference pilot pattern-inserted transmission data. A receiver includes a pilot pattern detector for OFDM-demodulating a data symbol received in a frame unit and detecting only a pilot pattern, and a BER operator for comparing the demodulated pilot pattern with a second reference pilot pattern, detecting and accumulating the number of pilot errors, and measuring a bit error rate by dividing the accumulated number of the pilot errors by the number of total received pilot patterns.

Abstract: A two-dimensional driving apparatus including: a plurality of support wires for elastically supporting a movable mount; a first driving device connected to the movable mount by a first driving wire capable of being elastically deformed for linearly moving the movable mount in a first direction; and a second driving device connected to the movable mount by a second driving wire capable of being elastically deformed, and installed at the same height of the first driving device for linearly moving the movable mount in a second direction perpendicular to the first direction.