Fixed threshold on-off keying differential detection for satellite optical communications

Shin, Won Ho; Choi, Jae Young; Han, Sang Kook

doi:10.1364/oe.27.001590

Cited by 13 publications

(9 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, as the SNR decreased, we find a higher likelihood for the neural network to improperly classify 'OFF' as 'ON' . implemented, including more complex adaptive threshold methods [47,48]. The neural network outperformed the threshold model in both scenarios.…”

Section: Resultsmentioning

confidence: 99%

Deep learning for enhanced free-space optical communications

Bart,

Savino,

Regmi

et al. 2023

Mach. Learn.: Sci. Technol.

View full text Add to dashboard Cite

Atmospheric effects, such as turbulence and background thermal noise, inhibit the propagation of light used in ON–OFF keying (OOK) free-space optical (FSO) communication. Here we present and experimentally validate a convolutional neural network (CNN) to reduce the bit error rate of FSO communication in post-processing that is significantly simpler and cheaper than existing solutions based on advanced optics. Our approach consists of two neural networks, the first determining the presence of bit sequences in thermal noise and turbulence and the second demodulating the bit sequences. All data used for training and testing our network is obtained experimentally by generating OOK bit streams, combining these with thermal light, and passing the resultant light through a turbulent water tank which we have verified mimics turbulence in the air to a high degree of accuracy. Our CNN improves detection accuracy over threshold classification schemes and has the capability to be integrated with current demodulation and error correction schemes.

show abstract

Section: Resultsmentioning

confidence: 99%

Deep learning for enhanced free-space optical communications

Bart,

Savino,

Regmi

et al. 2023

Mach. Learn.: Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Thus, the turbulence in the FSO channel is a time-dependent process and varies slowly (in the order of milliseconds) with the environment temperature and wind velocity [16]. Previous studies did not consider the effect of the slowly varying nature of the turbulent channel which is very important for Gbps rate transmission as the FSO channel varies at kHz rate [15], [17], [18]. Moreover, works have reported the performances of the BPSK coherent polarization division multiplexed (PDM) systems for FSO communication [19] to increase transmission capacity.…”

Section: Introductionmentioning

confidence: 99%

“…As the PDM-DPSK transmission performance gets affected by polarization, phase, and intensity fluctuation, it is needed to take into account the variations of these parameters as well.The strength of the polarization and phase fluctuations are also the function of (C 2 n ) value, so we can consider these fluctuations also time-dependent and varying slowly, similar to the turbulence channel states [12], [20], [21]. Thus for a Gbps rate FSO system, the turbulent channel coefficients remain constant for a block of bits [18] and a proper channel model needs to be implemented for estimating the performance of the PDM-DPSK system. The temporal irradiance fluctuation at the receiver has been observed in [9] and the temporally correlated Gamma-Gamma channel samples have been generated by using a time series generator.…”

Section: Introductionmentioning

confidence: 99%

Performance estimation of polarization multiplexed DPSK signal transmission over temporally correlated free space optical channel

Shukla

Gupta

2023

Opt Quant Electron

View full text Add to dashboard Cite

The performance of polarization division-mul tiplexing (PDM) differential phase-shift keying (DPSK) modulated signal transmission over a slow varying turbulence channel is estimated in this paper. The turbulent free space optical channel is simulated using a stochastic differential equation (SDE)-based numerical channel simulator that takes into account the temporal correlation effect of the channel. The SDE-based channel simulator model may significantly ease the free space optical (FSO) communication system design since it enables the simulation of channel states according to predefined first-and second-order statistics, namely channel distribution and auto-covariance. We report the performance comparison of the PDM-DPSK system over an uncorrelated fast-varying FSO channel and a time-correlated slow-varying channel. Furthermore, to incorporate the effects of polarization and phase fluctuations in the FSO link, both time-dependent and Gaussian-distributed, simulated using SDE methods. The bit error rate (BER) performance obtained from the numerical simulation of the PDM-DPSK system shows that the impact of intensity fluctuations is more severe than polarization and phase fluctuation. The power penalty relative to back-to-back (B2B) is 0.5 dB, 2.5 dB, and 7 dB for a 1 km FSO link to achieve a threshold BER of 10 −3 for weak, moderate, and strong turbulence

show abstract

“…The results are remarkable; however, only the gain saturation effect on the on-off keying (OOK) format was analyzed. In terms of symbol detection from the random fluctuation of the received light intensity, studies have been conducted to estimate the decision threshold on the OOK format [12][13][14][15]. The optimum decision needs perfect instantaneous channel state information (CSI), unavailable in practical systems.…”

Section: Introductionmentioning

confidence: 99%

“…Maximum likelihood (ML) symbol-by-symbol detection and ML sequence detection techniques were introduced theoretically. The receiver is assumed to know the channel model instead of instantaneous CSI [12,13]. Both ML symbol-by-symbol detection and ML sequence detection need the accurate marginal distribution of the turbulence-induced fading.…”

Section: Introductionmentioning

confidence: 99%

Stochastic Approximation Aided Adaptive Thresholding for Optical Detection in PAM4 Based FSO Transmission

2021

Self Cite

View full text Add to dashboard Cite

This study proposes an adaptive thresholding optical detection technique using a stochastic approximation (SA) to enhance receiver performance in multi-level pulse amplitude modulation (PAM) based free-space optical (FSO) transmission. When the receiver detects the symbol by fixed threshold decision (FTD) scheme, the detection performance of high order modulation, including PAM4, becomes degraded due to a random fluctuation of the received signal. Owing to the slow varying characteristic of atmospheric turbulence, we used an adaptive linear prediction (ALP) filter to predict the decision threshold of the upcoming frame. The experiment was conducted on various degrees of turbulence channels. A Mach-Zehnder modulator (MZM) based turbulence channel emulator was used to experimentally investigate the turbulence-induced scintillation effect. The experiment results confirmed that the proposed technique yielded improved receiver performance compared to FTD. In the case of considering the amplified spontaneous emission (ASE) noise of erbium-doped fiber amplifier (EDFA), the adaptive threshold decision (ATD) scheme obtained about 3dB gain compared with an even-valued threshold (EVT) decision scheme when the average EDFA input optical power was below -16dBm.

show abstract

Fixed threshold on-off keying differential detection for satellite optical communications

Cited by 13 publications

References 9 publications

Deep learning for enhanced free-space optical communications

Deep learning for enhanced free-space optical communications

Performance estimation of polarization multiplexed DPSK signal transmission over temporally correlated free space optical channel

Stochastic Approximation Aided Adaptive Thresholding for Optical Detection in PAM4 Based FSO Transmission

Contact Info

Product

Resources

About