Optimisation of subcarrier intensity modulation binary phase-shift keying free space optical link with avalanche photodiode receiver influenced by gamma–gamma atmospheric turbulence and pointing errors

2016 ◽  
Vol 10 (12) ◽  
pp. 1473-1479 ◽  
Author(s):  
Milica I. Petkovic ◽  
Dejan N. Milic ◽  
Goran T. Djordjevic
Keyword(s):  
Phase Shift ◽  
Atmospheric Turbulence ◽  
Free Space ◽  
Avalanche Photodiode ◽  
Phase Shift Keying ◽  
Free Space Optical ◽  
Optical Link ◽  
Pointing Errors ◽  
Shift Keying ◽  
Binary Phase Shift Keying

Performance Comparison of Free-Space Optical (FSO) Communication Link Under OOK, BPSK, DPSK, QPSK and 8-PSK Modulation Formats in the Presence of Strong Atmospheric Turbulence

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
A. K. M. Sharoar Jahan Choyon ◽  
Ruhin Chowdhury
Keyword(s):  
Phase Shift ◽  
Atmospheric Turbulence ◽  
Free Space ◽  
Communication Systems ◽  
Communication Link ◽  
Phase Shift Keying ◽  
Free Space Optical ◽  
Modulation Formats ◽  
Shift Keying ◽  
Ber Performance

AbstractFree-space optical (FSO) communication system provides several advantages over radio frequency (RF) system offering high bandwidth, low cost, small space requirements and more secure transmission which is free from Electromagnetic Interference (EMI). However, when the transmitted light signal passes through the atmosphere it experiences attenuation and fluctuations due to atmospheric turbulence. This paper analyzes the bit error rate (BER) performance of FSO communication systems under strong atmospheric turbulence for on-off keying (OOK), binary phase-shift keying (BPSK), differential phase shift keying (DPSK), quadrature phase shift keying (QPSK) and 8-phase shift keying (8-PSK) for link distances of 500, 1,000, 1,500 and 2,000 m. The probability density function (pdf) of the received irradiance is modelled using the gamma-gamma distribution model. It is found that the system exhibits the best BER performance and compensates the lowest power penalty at BER of 10 - 9 for BPSK modulation compared with other modulation techniques which makes BPSK more appropriate to be used with FSO turbulent system.

scholarly journals Performance Improvement for Mixed RF–FSO Communication System by Adopting Hybrid Subcarrier Intensity Modulation

2019 ◽  
Vol 9 (18) ◽  
pp. 3724 ◽  
Author(s):  
Jiang ◽  
Zhao ◽  
Liu ◽  
Deng ◽  
Luo ◽  
...  
Keyword(s):  
Atmospheric Turbulence ◽  
Channel Capacity ◽  
Communication System ◽  
Rayleigh Distribution ◽  
Intensity Modulation ◽  
Phase Shift Keying ◽  
Free Space Optical ◽  
Pointing Error ◽  
Shift Keying ◽  
Binary Phase Shift Keying

The improvement for hybrid radio frequency–free space optical (RF–FSO) communication system in wireless optical communications has acquired growing interests in recent years, but rarely improvement is based on hybrid modulation. Therefore, we conduct a research on end-to-end mixed RF–FSO system with the hybrid pulse position modulation–binary phase shift keying–subcarrier intensity modulation (PPM–BPSK–SIM) scheme. The RF link obeys Rayleigh distribution and the FSO link experiences Gamma–Gamma distribution. The average bit error rate (BER) for various PPM–BPSK–SIM schemes has been derived with consideration of atmospheric turbulence influence and pointing error condition. The outage probability and the average channel capacity of the system are discussed as well. Simulation results indicate that the pointing error aggravates the influence of atmospheric turbulence on the channel capacity, and the RF–FSO systematic performance is improved obviously while adopting PPM–BPSK–SIM under strong turbulence and severe pointing error conditions, especially, when the system average symbol length is greater than eight.

scholarly journals Bit Error Rate Analysis of Different Modulation Schemes in Free Space Optics Link using Gamma-Gamma Turbulence Model

2019 ◽  
Vol 8 (4) ◽  
pp. 8292-8295
Keyword(s):  
Phase Shift ◽  
Gamma Distribution ◽  
Bit Error Rate ◽  
Error Rate ◽  
Free Space ◽  
Channel Model ◽  
Distribution Model ◽  
Phase Shift Keying ◽  
Free Space Optical ◽  
Shift Keying

Free Space Optical (FSO) link using gamma-gamma channel model has been studied in this paper. Comparison of the probability density function of gamma-gamma distribution under weak and strong turbulence regime has been performed. Performance of Bit error rate (BER) using different subcarrier-intensity modulation (SIM) schemes such as binary phase shift keying (BPSK), M-ary phase shift keying (M-PSK) and quadrature amplitude modulation (QAM) have been also investigated. Using MATLAB software, the BER is plotted with respect to normalized signal to noise ratio (SNR) and the link distance. All the analysis has been done using the Gamma-Gamma distribution model. In this work we found that the effectiveness of each modulation technique depends on the environment.

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