Passive optical network system and implementation method based on Nyquist wavelength division multiplexing

Abstract

The invention discloses a passive optical network system based on Nyquist wavelength division multiplexing and a realization method. The system comprises an OLT (optical line terminal) and N ONUs(optical network unit), wherein the OLT is provided with a multi-carrier generation device and one three-port optical circulator; the multi-carrier generation device generates N paths of optical carriers with an equal frequency interval; N paths of downlink Nyquist wavelength division multiplexing signals are sent to the ONUs via a downlink feed line optical fiber; the three-port optical circulator transmits the N paths of optical carriers to the ONUs via an uplink feed line optical fiber for uplink modulation; and an uplink Nyquist wavelength division multiplexing signal from the ONUs is transmitted to the OLT via the uplink feed line optical fiber. According to the passive optical network system and the realization method., uplink and downlink both adopt the Nyquist wavelength division multiplexing technology, the advantage of WDM-PON (wavelength division multiplexing-passive optical network) is kept, the servable user amount is greatly increased by utilizing the high spectrum efficiency of the WDM-PON, and realization is simple.

Description

technical field [0001] The invention relates to a passive optical network, in particular to a passive optical network system and an implementation method based on Nyquist wavelength division multiplexing. Background technique [0002] With the rapid development of various high-bandwidth services, users' demand for network access bandwidth has increased significantly, and Passive Optical Network (PON, Passive Optical Network) has become an important technical means for user access. The PON system includes an optical line terminal (OLT: Optical Line Terminal) and an optical network unit (ONU: Optical Network Unites). Each ONU is connected to the OLT located in the central office through a remote node (RN: Remote Node). [0003] Wavelength division multiplexing PON (WDM-PON) is a technology with great advantages in transmission distance and capacity, and has become the mainstream of communication networks. In WDM-PON, each ONU works at different wavelengths. In the downlink tr...

AI Technical Summary

Problems solved by technology

However, limited by the principle of OFDM technology, when the upstream signal is multiplexed by OFDM at the remote node, it is necessary to ensure that the symbols from each ONU are aligned, which brings great difficulty to its implementation.

In addition, the digital signal processing of OFDM is relatively complex, and the bandwidth requirements of power generation and power receiving devices are relatively high. These are also obstacles that need to be overcome for the practical application of OFDM-PON.

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