Abstract: A method for automatic gain control of a front-end for a digital video receiver is provided. The method includes the following steps. First, a radio frequency signal is received and converted to an intermediate frequency signal. Then, the IF signal is amplified according to a gain. Next, the amplified IF signal is demodulated into a base-band signal, and the base-band signal is encoded into a transport stream. After that, a DC level of a pulse width modulation signal is controlled by at least one variable resistor to adjust the gain, the PWM signal being related to a setting of the gain. Afterwards, a BER measurement at each potential setting of the gain and the variable resistor under one or more power levels of the RF signal is read, and an optimum setting of the gain and the variable resistor is selected according to the BER measurements.

Abstract: A method for automatic gain control of a front-end for a digital video receiver is provided. The method includes the following steps. First, a radio frequency signal is received and converted to an intermediate frequency signal. Then, the IF signal is amplified according to a gain. Next, the amplified IF signal is demodulated into a base-band signal, and the base-band signal is encoded into a transport stream. After that, a DC level of a pulse width modulation signal is controlled by at least one variable resistor to adjust the gain, the PWM signal being related to a setting of the gain. Afterwards, a BER measurement at each potential setting of the gain and the variable resistor under one or more power levels of the RF signal is read, and an optimum setting of the gain and the variable resistor is selected according to the BER measurements.

Abstract: A data processing method of fast Fourier transform/inverse Fourier transform (FFT/IFFT) performed by a FFT/IFFT processor for used in a communication system is also disclosed. The FFT/IFFT processor includes a plurality of butterfly addition (BF) stages, the data includes a plurality of points, and each point includes a sign bit, at least one integral bit, and a plurality of decimal bits. The method comprises the steps of determining an overflow may occur in which of the BF stages when performing butterfly addition on the points of the data through detecting a preamble signal; and reserving one of the decimal bits of each point of the data to be an additional integral bit before performing the butterfly addition by the BF stage in which the overflow may occur.