OFDM-WDM-PON method and system for reducing PAPR by using DFT spread spectrum technology

Abstract

The invention discloses an OFDM-WDM-PON method and system for reducing PAPR by using DFT spread spectrum technology. The method comprises the following steps: generating a pseudorandom binary bit stream as downlink data; after serial / parallel conversion, carrying out 16QAM digital modulation mapping, and carrying out M-point discrete Fourier transform and N-M point subcarrier mapping on the modulated signal to realize DFT-S, performing N-point fast Fourier inversion and cyclic prefix adding, parallel / serial conversion and digital / analog conversion to obtain DFT-S OFDM signal; in an optical line terminal, loading DFT-S OFDM signal to an optical carrier by a Mach-Zehnder modulator, synthesizing optical signals with different wavelengths into one path of optical signal through a coupler, transmitting the optical signal to an optical network unit through an ODN, converting the optical signal into an electric signal through a photoelectric detector, and recovering the original signal through an inverse process of a transmitting end; and transmitting the uplink data from the ONU to the OLT through an inverse process of the downlink data.

Description

technical field [0001] The invention relates to the field of optical fiber communication, in particular to an OFDM-WDM-PON method and system for reducing PAPR by using DFT spread spectrum technology. Background technique [0002] With the diversified development of network services, the demand for broadband of various services continues to increase. The OFDM-WDM-PON system has become a better choice for the next-generation access network technology because of its unique advantages in solving the bottleneck of the access network technology rate. . Compared with the traditional WDM-PON system, after introducing Orthogonal Frequency Division Multiplexing (OFDM) technology into the optical passive access network (Passive optical network, PON), the transmission rate, anti-dispersion ability and network management etc. The advantages are obvious. However, since OFDM is a multi-carrier technology, the superimposed transmission of each carrier will lead to a higher peak-to-average...

AI Technical Summary

Problems solved by technology

However, since OFDM is a multi-carrier technology, the superimposed transmission of each carrier will lead to a higher peak-to-average power ratio (Peak-to-Average Power Ratio, PAPR), which requires network devices to have a larger linear range, thereby increasing system costs

At the same time, a higher peak-to-average power ratio (PAPR) will also aggravate the nonlinearity of optical fiber transmission, degrading system performance

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