Patent ID: 7885290

Claim:
A communication terminal apparatus for an optical network unit, that receives a management signal transmitted at a first bit rate and a data signal transmitted at a second bit rate, which is higher than the first bit rate, through a common line, the communication terminal apparatus comprising a band limiting unit that reduces a noise component contained in a received waveform by limiting a band; a signal regenerating unit that regenerates a waveform transmitted through the line as a signal having the first bit rate or the second bit rate; a timing controlling unit that controls timing for obtaining a data signal destined for the communication terminal apparatus based on a signal having the first bit rate regenerated by the signal regenerating unit, the timing controlling unit controlling the band limiting unit to limit the band at timing of receipt of the management signal and controlling the band limiting unit to lessen band limitation at timing of receipt of the data signal; and a data signal obtaining unit that obtains the data signal from a signal having the second bit rate regenerated by the signal regenerating unit according to timing control of the timing controlling unit, wherein the band limiting unit limits the band by modifying a resistance value of a feedback resistor in a preamplifier circuit that amplifies an input signal.