Abstract: Disclosed is an AGC (automatic gain control) device and method of an OFDM system with a DC offset compensation function, and a recording medium storing a program including the method. The AGC device calculates an energy of input signals with DC offsets as the summation of the square of the input signals, and calculates an energy of the DC offsets in the input signals as the summation of the square of the DC offsets. Pure signal energy without DC offsets is produced by subtracting the energy of the DC offsets from the energy of the calculated input signal. The energy and an AGC reference value are then compared, and feedback of a comparison result is performed.

Abstract: A method for calculating frequency offset using arc tangent calculations according to real part and imaginary part input values received externally. The method includes converting arc tangent equations for determining frequency offset into equations to perform log calculations; calculating frequency offset using linear approximation and the converted log equations; and dividing the real part input value to bit values of a predetermined size to realize a size similar to that of the imaginary part input value if a range of the frequency offset value to be calculated is small. With the use of the method, hardware area and power consumption may be reduced, and precise frequency offset may be calculated.

Abstract: There are provided inorganic/polymer composite particles having good UV-scattering efficiency and improved dispersion stability in organic formulation; and a method for preparing the same, which comprises the following steps of