US 2007/0177874 A1 · Optical access network system

Abstract

An optical access network system capable of transmitting and receiving high-speed signals and which allows the number of subscribers to be increased without increasing the number of wavelengths used is provided. An optical line terminal and an optical network unit are joined via an optical fiber transmitting line, a star coupler, and a plurality of branching optical fiber transmitting lines. The optical line terminal and optical network unit are constituted comprising an optical processing section and an electrical processing section. The optical processing section comprises a light-emitting element and a light-receiving element. The electrical processing section comprises a transmitting signal processing section that generates an encoded transmitting signal in the form of an electrical signal by encoding a transmitting signal and a receiving signal processing section that obtains a receiving signal by decoding a code-division-multiplexed signal that has been converted from optical-signal form to electrical-signal form by the light-receiving element. The optical access network system is characterized in that the decoding processing circuit that the receiving signal processing section comprises is constituted comprising an analog matched filter and a decision circuit.

Claims10

Dependent claims

An optical access network system in which a star coupler is provided at one end of an optical fiber transmitting line and which performs bidirectional optical communication by means of code division multiplexing, by allocating mutually different codes to each of a plurality of optical network units that are each joined to a plurality of branching optical fiber transmitting lines formed split by said star coupler, between an optical line terminal that is joined to the other end of said optical fiber transmitting line and said plurality of optical network units, wherein

each of said plurality of optical network units and said optical line terminal comprises:
a transmitting signal processing section for generating an encoded transmitting signal by encoding a transmitting signal and outputting said encoded transmitting signal;
and a receiving signal processing section for receiving a code-division-multiplexed signal that is transmitted after being code-division-multiplexed and for obtaining a receiving signal by decoding said code-division-multiplexed signal, and
said receiving signal processing section comprises a decoding processing circuit that decodes said code-division-multiplexed signal and said decoding processing circuit comprises an analog matched filter and a decision circuit,
said analog matched filter comprising an analog shift register, a positive signal adder, a negative signal adder, an analog adder that adds output signals from each of said positive signal adder and said negative signal adder, and a lowpass filter.

2 more elements

An optical access network system in which a star coupler is provided at one end of an optical fiber transmitting line, comprising an optical line terminal that is joined to the other end of said optical fiber transmitting line, and optical network units that are joined to each of N branching optical fiber transmitting lines (N is a natural number of two or more) formed with N branches by said star coupler, and in which first to Nth channels are allocated sequentially to said N optical network units and bidirectional communication using code-division-multiplexing is performed between said optical line terminal and said N optical network units, wherein

each of said N optical network units and said optical line terminal comprises a transmitting signal processing section that generates an encoded transmitting signal by encoding a transmitting signal and outputs said encoded transmitting signal, and a receiving signal processing section that receives an encoded receiving signal that is transmitted after being encoded and decodes said encoded receiving signal to extract and output a receiving signal, and
code that is set for said transmitting signal processing section that an optical network unit of a kth channel (k is a natural number from 1 to N) comprises which encodes and outputs an uplink signal which is a signal for transmitting from said optical network unit of said kth channel to said optical line terminal, and code that is set for said transmitting signal processing section that said optical line terminal comprises which encodes and outputs a downlink signal which is a signal for transmitting from said optical line terminal to said optical network unit of said kth channel are mutually different.

Dependencies are inferred from the claim text.

Optical access network system

Life of this patent

Optical access network system

Life of this patent

Abstract

Claims10