Patent ID: 6658217
Filing Date: 2003-12-02
Classification: H04B

Abstract:
A telephone station for an optical communication system, comprising:an optical coupler being optically connectable to another telephone station to receive an optical signal transmitted from the other telephone station and output an optical signal output; and an optical receiver for converting an optical signal received into an electrical signal to output the electric signal, said optical receiver being optically connected to said optical coupler to receive the optical signal output of said optical coupler, said optical receiver comprising: a photoelectric converter connected to receive the optical signal output by the optical coupler, and having an electric current signal output; a preamplifier connected to receive the current signal output by the photoelectric converter, and having a voltage signal output; an amplifier having a limiting function and connected to receive the voltage signal output by the preamplifier, to linearly amplify the voltage signal when the voltage signal is different from a reference voltage by less than or equal to a predetermined voltage, and to limitedly amplify said voltage signal when the voltage signal is different from the reference voltage by more than the predetermined voltage; and an automatic-gain-control amplifier connected to receive and amplify the output voltage signal of said amplifier having the limiting function, to output a signal having a constant swing, wherein the output signal swing of said amplifier having the limiting function satisfies the following relation within a desired dynamic range of said optical signal: &Dgr;VAWLwherein &Dgr;VAWL is the output signal swing of said amplifier having the limiting function; &Dgr;t is the time period to be occupied by a single optical bit; and Rs is the slew rate of said amplifier having the limiting function.