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.

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.

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.

scholarly journals On the Practical Implementation of VFDM-based Opportunistic Systems: Issues and Challenges

2012 ◽  
Vol 2 (1-2) ◽  
Author(s):  
Marco Maso ◽  
Leonardo S. Cardoso ◽  
Ejder Bastug ◽  
Nguyen Linh-Trung ◽  
Mérouane Debbah ◽  
...  
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Null Space ◽  
Delay Spread ◽  
Practical Implementation ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Test Bed ◽  
Short Root ◽  
The Impact ◽  
Secondary Link

Vandermonde-subspace frequency division multiplexing (VFDM) is a physical layer technique for cognitive two-tiered networks, allowing for the coexistence of an orthogonal frequency division multiplexing (OFDM) legacy system and a cognitive secondary system in a time division duplex mode. It consists of a linear null-space precoder used by the secondary transmitter to effectively cancel the interference towards one or more primary receivers, while guaranteeing a non-negligible rate to a served secondary receiver. In this work, we propose an implementation of an experimental test-bed using the new SDR4All platform developed at the Alcatel-Lucent Chair on Flexible Radio (SUPELEC) to take a step towards a proof of concept of a VFDM-based system. We focus on the secondary link, where an opportunistic transmitter/receiver pair communicates over moderately frequency selective channels, characterized by very short root mean square (r.m.s.) delay spreads and non uniform power delay profiles (PDP). The obtained results show the practical feasibility of a VFDM transmission over a secondary link. However, a significant bit error rate (BER) loss with respect to the previously shown achievable theoretical performance is evident. A thorough analysis of the structure of the VFDM precoder is carried out and the impact of the channel characteristics on the performance of the opportunistic system is discussed. Numerical findings demonstrate that the potential BER drop can be addressed by designing a suitable flexible receiver able to deal with the effect induced by non uniform PDP and short r.m.s. delay spread channels.

scholarly journals Dithering Analysis in an Orthogonal Frequency Division Multiplexing-Radio over Fiber Link

2016 ◽  
Vol 6 (3) ◽  
pp. 1112
Author(s):  
Fakhriy Hario P ◽  
Adhi Susanto ◽  
I Wayan Mustika ◽  
Sevia M Idrus ◽  
Sholeh Hadi P
Keyword(s):  
Optical Fibers ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Efficiency ◽  
Power Level ◽  
High Capacity ◽  
Coherent Detection ◽  
Frequency Division ◽  
Close Proximity ◽  
Qam Modulation ◽  
Fiber Link

Nonlinearity is one major problem broadband communication faced on utilizing the high capacity of optical fibers. That is due to scattering  phenomenon, which results in the deviations of wavelengths and energies. The dithering method is applied in the attempt to reduce those scatterings. In this paper, we propose the performance of a dithering technique based new system OFDM-RoF using two modulator scheme and coherent detection to alleviate the characteristics nonlinearity applied on the system. The dithering technique inputs signal externally to the signal processing systems to eliminate the effects of nonlinearity. Here, we report the performance of a dithering technique based on the OFDM-RoF, the results our experiment showed that the applied dithering with 16 QAM modulation can make the system more reliable and increases  the power level 1.55% with 193.1 THz, 2% with  100 THz and 1.99% ~ 200 THz, the best condition are with f<sub>d</sub> &lt; f<sub>c</sub>. However, all condition close proximity in the parameters OLP (optical launch power), BER and SER measurement. The result demonstrated a high efficiency and good power in which the OLP operated 6.396 dBm / 4.361 E-3 W~fd 200 THz, 3.578 dBm / 2.279 E-3 W~fd 193.1 THz and 6.420 dBm / 4.3384 E-3 W~100 THz. The best BER value is achieved at 0.33 and SER 0.78 at 5 km~f<sub>d</sub> 100 THz, 0.33 and 0.768 for 10 km~fd 193.1 THz, 0.478 and 0.92 for 50 km~fd 193.1 THz.

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