Deep Learning for Improving Performance of OOK Modulation Over FSO Turbulent Channels

Laialy Darwesh,Natan S Kopeika

doi:10.1109/access.2020.3019113

Laialy Darwesh, Natan S Kopeika

Open Access

https://doi.org/10.1109/access.2020.3019113

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Abstract

Free space optical (FSO) communication technology has become increasingly advanced with capabilities of high speed, high capacity, and low power consumption. However, despite the great potential of FSO, its performance is limited in a turbulent atmosphere. Atmospheric turbulence causes scintillation in the FSO propagated signals, leading to an increase in the bit error rate (BER) performance of the recovered signals at the receiver. In this paper, we demonstrate that the use of deep learning (DL) detection methods could overcome these limitations. We present a new detection method of on-off keying (OOK) modulated signals by using different models of DL over different strength FSO turbulent channels, without the need for prior knowledge of the parameters of the channel. The demonstrated DL decoders improve the performance of the FSO turbulent channel and decrease the power consumption. Moreover, the demonstrated DL models also work faster than maximum likelihood (ML) methods with perfect channel estimation decoders, with even slightly better performance because of the turbulence, thus enabling realization of FSO over turbulent atmospheric channels.

Highlights

Free space optical (FSO) communication has gained significant attention in recent years due to its high bandwidth and data rate capabilities
FSO transmitted signals are very sensitive to these fluctuations that lead to changes in the amplitude and the phase of the received signal. This can affect the performance of FSO systems and lead to significant increases in the values of the bit error rate (BER), which can limit the implementation of FSO communication systems in real environments such as in data centers
The results indicate that our deep learning (DL) decoders performed approximately like the maximum likelihood (ML) decoder with perfect channel state information (CSI) when the channel is described by weak atmospheric turbulence

Summary

Introduction

Free space optical (FSO) communication has gained significant attention in recent years due to its high bandwidth and data rate capabilities. B. PROPOSED DL DETECTION MODELS we present a new DL detection method for OOK with IM/DD modulation to enable the use of FSO communication in different turbulent channels without the need of prior channel.

Results

Conclusion