ROF-PON full duplex system based on optical comb and carrier wave reuse

• Main Authors: LI CHAO, ZHENG JINGJING, CHEN HONGYAO, YUAN JIN, ZHANG CHAN, NING TIGANG
• Format: Patent
• Language: English
• Published: 15.07.2015
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; MULTIPLEX COMMUNICATION; TRANSMISSION

The utility model discloses a ROF-PON full duplex system based on an optical comb and carrier wave reuse. The scheme is shown as the drawing 1. A local oscillation source with a frequency of 10GHz drives an electric absorption modulator connected to a phase modulator and an intensity modulator to generate the flat optical comb with a frequency space of 10GHz. A central carrier wave is separated from other carrier waves through a raster filter having a wave length same as that of the central carrier wave of the optical comb and an optical circulator. The separated central carrier wave comprises two paths, one of which is used as beat frequency light of a down link without loading any signal carrier wave reuse, and the other one of which is used as an up carrier wave for loading an up data and converting the up data to an electrical signal of a base band through a low-speed photoelectric detector. A down wireless data is modulated to the other carrier waves except from the central carrier wave and is transmitted to RN through an optical fiber. The RN receives optical signals sent from OLT; the optical signals are separated according to different wave lengths via an array waveguide raster; and any one sideband carrying down data is selected and is combined with a central carrier wave of an un-modulated data to form an optical millimeter wave ROF signal having a frequency of 60GHz; and the optical millimeter wave ROF signal is subjected to photovoltaic conversion through a photoelectric detector and is sent to a wireless user through an amplifier and an antenna. The optical comb and carrier wave reuse are used in the system, so that a reuse system shared by a single light source and an up/down light source is realized, and a balance between economical efficiency and system performance can be realized.