Flexible bandwidth allocation based orthogonal frequency-division multiplexing passive optical network

Abstract

A flexible bandwidth allocation based orthogonal frequency-division multiplexing passive optical network in the field optical communication comprises a laser device, an electric absorption modulator, an erbium-doped optical fiber amplifier, a dimmable filter, a beam splitter, a signal generator and a plurality of ONU, wherein the laser device, the electric absorption modulator, the erbium-doped optical fiber amplifier, the dimmable filter and the beam splitter are arranged on an optical line terminal and connected sequentially, the output end of the signal generator is connected with a radio frequency port of the electric absorption modulator and outputs an analog OFDM signal, an orthogonal frequency-division multiplexing signal produced by the signal generator loaded to an optical carrier waves emitted by the laser device through the electric absorption modulator to form an optical signal, is sequentially subjected to modulation, signal amplification, filtering and denoising and is sent to all signal receiving ends by the beam splitter to be recovered into downlink data. The flexible bandwidth allocation based orthogonal frequency-division multiplexing passive optical network reasonably allocates ONU on subcarrier waves of an OFDM for the downlink data, and accordingly avoids the influence off power loss caused by chromatic dispersion and chirp. Therefore, the subcarrier waves of the OFDM can be modulated through a high-order QAM code pattern, and large-capacity transmission is achieved.

Description

technical field [0001] The invention relates to a technology in the communication field, in particular to a flexible bandwidth allocation scheme to realize a large-capacity, low-cost and long-distance Orthogonal Frequency Division Multiple Access Passive Optical Network (OFDMA PON). Background technique [0002] At present, with the rapid development of science and technology, the process of social informatization is accelerating, the Internet is widely popularized, data services are increasing greatly, and people's demand for broadband services is growing rapidly. [0003] Due to its simple structure, low cost and flexible configuration, passive optical network (PON) technology not only avoids the electromagnetic interference and environmental impact of external equipment, reduces the failure rate of lines and external equipment, improves the reliability of the system, and saves It reduces maintenance costs and has become a competitive solution for users to realize broadban...

AI Technical Summary

Problems solved by technology

However, this scheme still has the following disadvantages: the OFDM signal generated by the above-mentioned transmitter is a double sideband (DSB) signal, which will cause serious power loss caused by dispersion and chirp

Although this technology can improve the sensitivity of the receiver, it cannot flexibly allocate bandwidth according to the distance, resulting in the waste of some frequency bands, which in turn limits the transmission capacity of the system

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