scholarly journals Study and Simulation of Transporting Radio Frequency Signals over Free Space Optics for Achieving High Data Rate and Power Saving

2021 ◽  
Vol 15 (16) ◽  
pp. 79
Author(s):  
Isam Aameer Ibrahim ◽  
Tahreer Safa’a Mansour
Keyword(s):  
Mathematical Model ◽  
Radio Frequency ◽  
Free Space ◽  
Free Space Optics ◽  
Space Optics ◽  
Rf Signals ◽  
Shift Keying ◽  
Radio Frequency Signals ◽  
Simulation Results ◽  
Modulation Schemes

The remarkable technology for seamless integration of wireless and optical networks is radio frequency signals over Free Space Optics (FSO). This research study and simulation examine the design and evaluation performance of Radio Frequency over FSO (RF-FSO) wireless communication technology. These systems are implemented through medium communication link ranges to overcome excessive sensitivity of atmosphere medium and meet the requirements of a wide variety of optical wireless applications. There are two ways to achieve the application of the design mentioned above. The first way is the application of the  Three modulation schemes of technology that is Amplitude shift keying (ASK), Quadrature amplitude modulation (QAM), and Quadrature phase-shift keying (QPSK) of digital modulation. The design of these modulation schemes is realized by using optiwave software to study the transmission of RF signals over the FSO channel and compare the three modulation techniques into the RF-FSO system. RF signals with the frequency range from (20 to 60) GHz is used in RF-FSO system and many carrier optical signals where the higher RF has a wider bandwidth to carrying larger information. To increase the transmission of data rates Wavelength Division Multiplexing (WDM) technology is used. The second way is based on a mathematical model which has been proposed for this study. This mathematical model calculates optimal beacon period (BI), and optimal listen interval (LI) to preventing the overlapping of time between the signals and the decrease in the required power. Using different weather conditions samples, the simulation results revealed that the best performance of the RF-FSO system is from link range, and the receiver is more sensitive. The simulation results are as follows: Two independent channels are transmitted 20 Gbps over ranges from (263 m to 6.55 km), while four channels are transmitted 40 Gbps over ranges from (257 m to 5.95 km), and eight independent channels transmit 80 Gbps over distance from (203 m to 5.2 km)

Free space optics communication channel with amplitude/frequency shift keying modulation technique based raised cosine line coding

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mahmoud M.A. Eid ◽  
Vishal Sorathiya ◽  
Sunil Lavadiya ◽  
Ismail A. Abd El-Aziz ◽  
Ahmed Nabih Zaki Rashed
Keyword(s):  
Frequency Shift ◽  
Free Space ◽  
Optical Signal ◽  
Channel Length ◽  
Free Space Optics ◽  
Noise Power ◽  
Frequency Shift Keying ◽  
Space Optics ◽  
Shift Keying ◽  
Modulation Schemes

Abstract The objective of the study is to simulate frequency shift keying (FSK)/amplitude shift keying (ASK) modulation schemes with raised cosine line coding based free space optics channel in clear weather conditions. The max. Q and optical signal/noise ratio (OSNR) with FSO channel length variations are simulated for the previous and proposed models at DRs of 10 Gbps, and also the max. Q factor with data rate (DR) variations is demonstrated for the previous and proposed models at 10 km FSO channel length. Max. Q, min. BER, signal power (SP), noise power, and total optical power (TOP) based FSK and ASK modulation schemes are illustrated through APD receiver with FSO channel length of 10 km.

Mitigation of Atmospheric Turbulences Using Mode Division Multiplexing based on Decision Feedback Equalizer for Free Space Optics

2020 ◽  
Vol 41 (2) ◽  
pp. 185-193 ◽  
Author(s):  
Abdullah Almogahed ◽  
Angela Amphawan ◽  
Yousef Fazea
Keyword(s):  
Free Space ◽  
Minimum Mean Square Error ◽  
Decision Feedback ◽  
Free Space Optics ◽  
Decision Feedback Equalizer ◽  
Free Space Optical ◽  
Space Optics ◽  
Link Distance ◽  
Mode Division Multiplexing ◽  
Simulation Results

AbstractIn mode division multiplexing (MDM) free space optical (FSO) communication system, the atmospheric turbulences such as fog, rain, and haze cause adverse effects on system performance. This paper investigates the mitigation of atmospheric turbulences of FSO using MDM and decision feedback equalizer (DFE) with minimum mean square error (MMSE) algorithm. The implementation of the MMSE algorithm is used to optimize both the feedforward and the feedback filter coefficients of DFE. The proposed system comprises three parallel 2.5Gbit/s channels using Hermite–Gaussian modes. A data rate of 7.5Gbit/s over 40 m, 800 m, 1400 m, and 2km under medium fog, rain, haze, and clear weather, respectively, has been achieved. In addition, it is noticed that the link distance is reduced while increasing the attenuation. The simulation results revealed that a DFE improves the performance MDM FSO system while maintaining high throughput and desired low bit error rate.

scholarly journals Free Space Optics Vs Radio Frequency Wireless Communication

2016 ◽  
Vol 8 (9) ◽  
pp. 1-8 ◽  
Author(s):  
Rayan A. Alsemmeari ◽  
◽  
Sheikh Tahir Bakhsh ◽  
Hani Alsemmeari
Keyword(s):  
Wireless Communication ◽  
Radio Frequency ◽  
Free Space ◽  
Free Space Optics ◽  
Space Optics

scholarly journals Performance Evaluation of Log-normal And Negative Exponential Channel Modeling Using Various Modulation Techniques in OFDM-FSO Communication

2005 ◽  
Vol 4 (2) ◽  
pp. 639-647
Author(s):  
Nitin Shankar Singh ◽  
Gurpartap Singh
Keyword(s):  
Phase Shift ◽  
Bit Error Rate ◽  
Error Rate ◽  
Free Space ◽  
Free Space Optics ◽  
Phase Shift Keying ◽  
Space Optics ◽  
Modulation Techniques ◽  
Shift Keying ◽  
Negative Exponential

Free Space Optics (FSO) is one of the emerging technology which is thoroughly being popular and is basically using optical signals for the communication. The paper evaluates the bit error rate performance of the Free space Optics (FSO) system. To design a high performance communication link for the atmospheric FSO channel, it is of great importance to characterize the channel with proper model. The performance of the highly efficient, high data rate system is limited by the certain constraints like scintillation effects and atmospheric turbulence. The FSO communication system using Orthogonal Frequency Division Multiplexing (OFDM) technique which is known for its increased robustness against frequency selective fading, narrow-band interference and high channel efficiency. The performance of the modulation techniques- Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK) and 8-PSK are studied in the Lognormal and Negative Exponential channel. The obtained results are the comparative study of Bit Error Rate (BER) vs. Signal to Noise Ratio (SNR), which is quite useful for analyse the system performance with different channel models for various modulation techniques.

Comparison of link selection algorithms for free space optics/radio frequency hybrid network

2011 ◽  
Vol 5 (18) ◽  
pp. 2751-2759 ◽  
Author(s):  
F. Nadeem ◽  
M. Loeschnig ◽  
B. Geiger ◽  
G. Kandus ◽  
E. Leitgeb ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Free Space ◽  
Hybrid Network ◽  
Free Space Optics ◽  
Space Optics ◽  
Selection Algorithms
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