Optical orthogonal frequency division multiplexing system and method based on avalanche photodiode

Abstract

The invention provides an optical orthogonal frequency division multiplexing system based on an avalanche photodiode and a method thereof. The method comprises the steps that an off-line DSB (Double Side-Band Transmission) module of a signal source device in the system produces a path of digital electrical signals with the modulation format being 4QAM-OFDM, and a digital-to-analog converter converts the digital electrical signals into analog electrical signals; an optical link device modulates the received analog electrical signals to optical carrier wave to be uploaded to a distant receiving terminal, and performs photoelectric detection on the analog electrical signals through the avalanche photodiode with high sensitivity, so as to realize optoelectronic conversion and obtain the analog electrical signals; and a signal processing device performs bandpass filtering, analog-to-digital conversion and demodulation on the received analog electrical signals, so as to obtain high-speed data bit including information, thereby realizing the transmission of optical orthogonal frequency division multiplexing.

Description

Technical field [0001] The present invention involves communication technology, and specially involves a system and method of optical orthopedic frequency reuse based on the high -sensitivity of the avalanche optoelectronics diode. Background technique [0002] Since the development of communication technology, it is divided into two periods: simulation modulation and digital modulation in terms of modulation method.During the digital modulation phase, it has also undergone multiple stages such as amplitude modulation (ASK), frequency shifting key control (FSK), migrant key control (PSK), and multi -advancement modulation.Especially in the field of PSK research and application, the improvement of spectrum utilization and error rates has been continuously innovated, thus the evolution from 2PSK to MPSK, including the most widely used in the mobile communications industry (the minimum shift frequency key of the Gaussian filtering frequency keyControl) GMSK.Today, a new type of modu...

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Problems solved by technology

[0013] The above is the existing OOFDM system, which can preliminarily realize the transmission of the low-power OFDM electrical signal in the light. The bit error rate of the OFDM electrical signal after the modulation format is high, which limits the long-distance transmission of the high bit rate modulation format of the OFDM electrical signal on the optical fiber to a large extent.

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