Abstract: In a complex modulation/demodulation method and system, the data frequency f.sub.C1 of data signals I and Q inputted to a constellation mapping circuit is converted by a digital interpolation circuit into a sampling frequency f.sub.C2 equal to f.sub.S /N, where f.sub.S is an operation sampling frequency and N is selected such that the signal maximum frequency of the data signals I and Q becomes lower than f.sub.C2 /2. The interpolated data signals I and Q are respectively inputted to real and imaginary input terminals of a complex coefficient band pass filter to extract a real signal output. An output signal of the complex coefficient band pass filter is converted by a DA converter into an analog signal from which desired frequency components are extracted by an analog band pass filter, thereby performing a quadrature modulation.

Abstract: The object of the present invention is to provide an aluminum plate for fabrication which has an excellent formability, easy degrease after fabrication, coating properties, and less tendency of flawing, in which the aluminum plate for fabrication which is plated, and coated with a lubricant containing (A) a fatty acid ester of polyol, (B) an alkaline or alkaline metal salt of sulfonate, and (C) a controlling agent, and having saponification value of 20 or more.