Wavelength division multiplexing OFDM-PON transmission system based on remote difference frequency detection

Abstract

The invention provides a wavelength division multiplexing OFDM-PON transmission system based on remote difference frequency detection. The system comprises an optical line terminal, a feed-in type optical fiber network, a far-end node, multiple distribution type optical fiber networks and multiple optical network units which are connected in turn. The optical network units are used for processing a downlink OFDM signal and extracting a specific X-polarized optical carrier used for modulating an uplink OFDM signal. Heterodyne detection of the downlink OFDM signal and a downlink local oscillator optical signal is realized by the optical network units, and the uplink OFDM signal is outputted to the far-end node and the optical line terminal via the distribution type optical fiber networks simultaneously. The optical line terminal receives the uplink OFDM signal and performs self-homodyne detection on the uplink OFDM signal. With adoption of an OFDM and WDM reuse mode, effective transmission channels and data transmission rate are increased so that larger transmission capacity is realized. Meanwhile, receiving sensitivity is enhanced by adopting the difference frequency detection technology so that transmission in longer distance is realized.

Description

technical field [0001] The present invention relates to a system and method in the technical field of optical communication, in particular to a wavelength division multiplexing OFDM-PON transmission system based on remote difference frequency detection. Background technique [0002] Some scholars have proposed to integrate WDM technology into OFDM-PON due to the optical beat frequency interference generated by the signal at the OLT receiving end, and OFDM-PON to achieve high uplink and downlink rates, large capacity, and high stability. At present, the OFDM-PON system based on WDM technology (WDM-OFDM-PON) is considered to be a relatively ideal and promising optical access network technology. However, the multi-wavelength light source problem brought by WDM-OFDM-PON will lead to an increase in system cost, so the colorless technology of ONU is the key technology of WDM-OFDM-PON system. [0003] After searching the existing literature, it was found that Jianjun, Y.H and othe...

AI Technical Summary

Problems solved by technology

[0006] The system provided by the present invention modulates downlink data and control signaling on an optical carrier generated by the double sideband suppressed carrier module, and then couples with another unmodulated optical carrier (downlink local oscillator) and transmits them to the optical network unit ONU , and the remote heterodyne detection is realized through ordinary photodetectors at the optical network unit, reducin

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