Optical-fiber wireless system for full-duplex communication

Abstract

The invention relates to an optical-fiber wireless system for full-duplex communication, which consists of a central station and a base station, wherein the central station and the base station are connected through an optical-fiber transmission links; the central station generates subcarrier signals by mixing baseband signals with radio frequency sine-wave signals, generates optical double-sideband differential phase-shift keying signals through the modulation of an optical phase modulator, performs power amplification, and then transmits the signals to the base station; the base station separates the signals transmitted by the central station; the signals are divided into an upper way and a lower way through an optical splitter; the upper way generates carrier-suppressed differential phase-shift keying optical-carried millimeter waves which are converted into downlink millimeter wave signals through photoelectric conversion and then sent to wireless terminals through antennas; the lower way generates reference local oscillator signals through photoelectric conversion, mixes the reference local oscillator signals with uplink millimeter wave signals, and generates uplink baseband signals through down conversion; and central carrier waves are re-modulated by the uplink baseband signals and then transmitted back to the central station. The system has the advantages of simplifying generation devices for optical-carried millimeter waves and reducing cost, along with simple flexible structure, strong extensibility, more compact structure and easiness for integration.

Description

technical field [0001] The present invention relates to a kind of optical fiber-wireless (Radio-Over-Fiber, abbreviated as ROF) communication technology, especially a kind of generation of carrier suppression-differential phase shift keying optical carrier millimeter wave signal, and realize the full duplex of optical fiber wireless system communication. technical background [0002] Optical fiber-wireless communication technology uses optical fiber links to transmit radio signals, and organically combines the characteristics of broadband wireless communication such as mobility and point-to-multipoint access with the ultra-bandwidth and high reliability of optical fiber communication to provide large-capacity, low-cost Wired transmission of radio signals and ultra-broadband wireless access exceeding Gbit / s provide an ideal solution. For fiber-optic wireless systems, the generation of high-quality optical-borne millimeter waves is one of the key technologies for realizing co...

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Problems solved by technology

However, since the two-electrode M-Z modulator used in this system is based on carrier suppression modulation, it is necessary to load a pair of anti-phase subcarrier drive signals on the upper and lower arms of the two-electrode M-Z modulator; and it is also necessary to configure complex peripherals Control Circuits to Eliminate DC Bias Drift Problems of Two-Electrode M-Z Modulators

Therefore, the system requires a large number of electrical components, and the signal processing in the electrical domain is relatively complicated.

On the other hand, since the system use

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