Improved Performance Investigation of 10 Gb/s–10 GHz 4-QAM Based OFDM-Ro-FSO Transmission Link

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Amit Grover ◽  
Anu Sheetal
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Free Space Optics ◽  
Frequency Division ◽  
Atmospheric Conditions ◽  
Space Optics ◽  
Link Distance ◽  
Received Power ◽  
Transmission Link ◽  
Improved Performance ◽  
Root Module

AbstractIn this work, a 10 Gb/s–10 GHz hybrid orthogonal frequency division multiplexing (OFDM)-radio-over-free space optics (Ro-FSO) transmission link using 4-level quadrature amplitude modulation (QAM) has been modeled and its performance is investigated under different atmospheric conditions and system parameters. A link distance of 4000 m at 10 Gb/s was achieved using the proposed link. Also, an improved performance by using a square root module (SRm) at the receiver end has been demonstrated. The results show a significant improvement in SNR and total received power using the proposed detection technique.

A long-reach radio over free space optics (Ro-FSO) system using hybrid orthogonal frequency division multiplexing (OFDM)-multibeam concept with enhanced detection

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Peramandai Govindasamy Kuppusamy ◽  
Kotteswaran Rajkumar ◽  
Rajagopal Maheswar ◽  
Soundarapandian Sheeba Rani ◽  
Iraj Sadegh Amiri
Keyword(s):  
Free Space ◽  
Orthogonal Frequency Division Multiplexing ◽  
Free Space Optics ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Detection Mechanism ◽  
Space Optics ◽  
Modulation Format ◽  
Single Sideband Modulation ◽  
Improved Performance

AbstractThis paper focuses on designing of a 10 Gbit/s-10GHz hybrid Orthogonal frequency division multiplexing (FDM) based Radio over Free Space Optics (Ro-FSO) transmission link using optical single sideband modulation format and its performance has been compared using a different number of transmission beams. The proposed link has been simulated and compared using 1-beam, 2-beam, and 4-beam in the system. We show that by using the 4-beam system in the OFDM-Ro-FSO link, a 3000 m range has been achieved reliably, which a notable improvement when compared to previous work is. Also, we show an improved performance of the system by using an enhanced detection mechanism using a Square root module (SRm) at the receiver side.

Improved Performance Analysis of Free Space Optics Communication Link under Rain Conditions using EDFA Pre-amplifier

2018 ◽  
Vol 39 (2) ◽  
pp. 241-246 ◽  
Author(s):  
Mehtab Singh
Keyword(s):  
Performance Analysis ◽  
Free Space ◽  
Weather Conditions ◽  
Fiber Amplifier ◽  
Free Space Optics ◽  
Communication Link ◽  
Erbium Doped Fiber Amplifier ◽  
Space Optics ◽  
Link Distance ◽  
Improved Performance

AbstractFree Space Optics (FSO) also known as Optical Wireless Communication (OWC) is a communication technology in which free space/air is used as the propagation medium and optical signals are used as the information carriers. One of the most crucial factors which degrade the performance of FSO link is the signal attenuation due to different atmospheric weather conditions such as haze, rain, storm, and fog. In this paper, an improved performance analysis of a 2.5 Gbps FSO link under rain conditions has been reported using Erbium-Doped Fiber Amplifier (EDFA) as a pre-amplifier. The results show that the maximum link distance for an FSO link under rain weather conditions with acceptable performance levels (Q$$\sim6$$and BER$$ \le {10^{- 9}})$$in the absence of EDFA pre-amplifier is 1,250 m which increases to 1,675 m with the use of EDFA pre-amplifier.

Performance investigation of free space optics link employing polarization division multiplexing and coherent detection-orthogonal frequency division multiplexing under different link parameters

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Tanu Shri ◽  
Anita Suman ◽  
Parveen Kumar
Keyword(s):  
Free Space ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Capacity ◽  
Coherent Detection ◽  
Free Space Optics ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Test Bed ◽  
Space Optics ◽  
Polarization Division Multiplexing

AbstractFree space optics (FSO) is a novel transmission technique capable of providing high-capacity links with large bandwidth and robustness against electromagnetic waves interference. In this work, we demonstrate the development of a 100 Gbps FSO link which employs the hybridization of polarization division multiplexing technique and coherent detection-orthogonal frequency division multiplexing technique. Further, we have investigated the system performance by varying different parameters like the input power, the size of the receiver antenna, wavelength of laser beam, the angle of beam divergence, and the additional losses. The proposed system has been modeled and analyzed over Optisystem test bed.

Performance comparison of code division multiple access and orthogonal frequency division multiplexing over turbulent effected free space optics link under the impact of advance coding formats

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Heena Arora ◽  
Vishal Sharma
Keyword(s):  
Free Space ◽  
Code Division Multiple Access ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Access ◽  
Data Rate ◽  
Free Space Optics ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Space Optics ◽  
Code Division Multiple

Abstract Free space optics (FSO) systems have gained considerable attention because of their numerous features and services. It has evolved into a promising technology for high data rate transmission in wireless communication systems. However, there are some atmospheric effects which inhibit its performance. In this paper, performance of code division multiple access–free space optics (CDMA–FSO) by combining multidiagonal (MD) codes and orthogonal frequency division multiplexing–free space optics (OFDM-FSO) systems over using advance line coding formats under the sway of turbulence conditions are investigated and compared. A comparative study has shown that CDMA–FSO offers better SNR with both CSRZ and AMI coding format under diverse conditions at data rate 15 and 20 Gbps.

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.

Hybrid Analog/Digital Modulations Using Polarization Multiplexing OCDMA Scheme in Free Space Optics

2015 ◽  
Vol 764-765 ◽  
pp. 511-514
Author(s):  
Chih Ta Yen ◽  
Chia Yu Liu
Keyword(s):  
Free Space ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Access ◽  
High Speed ◽  
Base Station ◽  
Free Space Optics ◽  
Detection Scheme ◽  
Space Optics ◽  
Polarization Multiplexing ◽  
Code Division Multiple

With the development of the Internet, how to provide a high-speed and high-security comprehensive network has become urgent issue. In this project, we propose hybrid analog/digital transmissions format scheme which integrated optical code-division multiple-access (OCDMA) and polarization multiplexing technique in free space optics (FSO) transmission. Orthogonal frequency division multiplexing (OFDM) transmits as the analog format and (on-off keying) OOK transmits as digital format in the study, respectively. In the proposed hybrid OCDMA system, it has high-speed transmission, signal security and low cost...etc. we adopt quasi-orthogonal Walsh-Hadamard codes (WHC) that with fixed cross correlation value as the codeword for each base station. With the property, the multiple access interference (MAI) can be efficiently eliminated by using the balanced detection scheme at the receive end. The constellation and eye diagrams show that both OFDM signal as analog signal and OOK modulation as digital signal in the proposed hybrid OCDMA system perform good performance in FSO transmission.

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