Modelling of 10 Gbps Free Space Optics Communication Link Using Array of Receivers in Moderate and Harsh Weather Conditions

2017 ◽  
Vol 38 (3) ◽  
Author(s):  
Amit Gupta ◽  
Nagpal Shaina

AbstractIntersymbol interference and attenuation of signal are two major parameters affecting the quality of transmission in Free Space Optical (FSO) Communication link. In this paper, the impact of these parameters on FSO communication link is analysed for delivering high-quality data transmission. The performance of the link is investigated under the influence of amplifier in the link. The performance parameters of the link like minimum bit error rate, received signal power and Quality factor are examined by employing erbium-doped fibre amplifier in the link. The effects of amplifier are visualized with the amount of received power. Further, the link is simulated for moderate weather conditions at various attenuation levels on transmitted signal. Finally, the designed link is analysed in adverse weather conditions by using high-power laser source for optimum performance.

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Bentahar Attaouia ◽  
Kandouci Malika ◽  
Ghouali Samir

AbstractThis work is focused to carry out the investigation of wavelength division multiplexing (WDM) approach on free space optical (FSO) transmission systems using Erbium Ytterbium Doped Waveguide Amplifier (EYDWA) integrated as post-or pre-amplifier for extending the reach to 30 Km for the cost-effective implementation of FSO system considering weather conditions. Furthermore, the performance of proposed FSO-wavelength division multiplexing (WDM) system is also evaluated on the effect of varying the FSO range and results are reported in terms of Q factor, BER, and eye diagrams. It has been found that, under clear rain the post-amplification was performed and was able to reach transmission distance over 27 Km, whereas, the FSO distance has been limited at 19.5 Km by using pre-amplification.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Bithi Mitra ◽  
Md. Jahedul Islam

AbstractIn this paper, the performance of two-dimensional (2-D) wavelength-hopping/time-spreading (WH/TS) optical code division multiple access (OCDMA) system over free space optical (FSO) channel is analyzed in the presence of pointing error and different weather conditions. Prime code scheme is employed for both wavelength-hopping and time-spreading to address user code-matrix. The operating central wavelength of 1550 nm is considered to demonstrate the bit error rate (BER) performance of the proposed system as a function of various system parameters. The required optical power of the proposed system is determined to maintain a BER value of 10−9. The numerical evaluation interprets that the BER performance is highly dependent on transmission length, transmitted power, pointing error angle as well as the number of simultaneous user. It is also observed that the 2-D OCDMA system over free space needs minimum required optical power in case of rainy atmospheric condition, but it is maximum for foggy atmospheric condition.


2018 ◽  
Vol 39 (2) ◽  
pp. 241-246 ◽  
Author(s):  
Mehtab Singh

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.


2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Mehtab Singh ◽  
Vigneswaran Dhasarathan

AbstractThe exponential rise in the demand for channel bandwidth over the last few years has lead to the problem of spectrum congestion in conventional radio frequency (RF)-based wireless communication systems. Radio over free space optics (RoFSO) provides an effective solution to tackle the problem of spectrum congestion due to its many merits including license-free bandwidth, quick and low-cost installation, cost-effectiveness, and highly secure transmission links. The high-speed data transmission capabilities and immunity to electromagnetic and RF interference makes it a suitable candidate for the development of future 5 G networks. This work focuses on the designing and performance analysis of 10 Gbit/s–10 GHz orthogonal frequency division multiplexing (OFDM) based RoFSO link under the impact of different environmental effects. Also, the performance of the proposed RoFSO link has been compared for different modulation schemes viz. optical dual sideband (ODSB) and optical single sideband (OSSB). Further, we propose an enhanced detection technique deploying Square root module (SRm) at the receiver terminal for link reach enhancement under the impact of adverse weather conditions.


2018 ◽  
Vol 39 (3) ◽  
pp. 335-341 ◽  
Author(s):  
Gaurav Soni

Abstract Free Space Optics (FSO) communication technique is a unique method for the communication between optical transmitter and optical receiver using a free space as a medium. The advantages of FSO over other wireless communication techniques is its low power, high security, low cost infrastructure, high data rates and unlicensed spectrum. There are many atmospheric disturbances like rain, fog, water molecules particles which degrade the performance of the FSO Link. In this paper, the FSO Link is optimized at different optical wavelengths of 1550 nm, 850 nm, 650 nm and 532 nm keeping into consideration the various atmospheric challenges and weather conditions. The performance of the proposed FSO link is evaluated in terms of BER and Quality factor. Simulation results for the proposed FSO link achieve maximum link range of 1000 m at 1550 nm. The achieved values of Bit Error Rate (BER) and Quality Factor (Q) for FSO link at 1550 nm are 10e-9 and 5.58 respectively.


2021 ◽  
Vol 9 ◽  
Author(s):  
Sushank Chaudhary ◽  
Lunchakorn Wuttisittikulkij ◽  
Jamel Nebhen ◽  
Xuan Tang ◽  
Muhammad Saadi ◽  
...  

High-speed data demand in sensitive locations has prompted new wireless technologies to grow in areas like hospitals for bio-sensor data transmission between doctors and patients. However, interference of electromagnetic spectrum or highly sensitive medical equipment in such locations can prevent radio waves which can further compromise the health of patients. Radio over Free Space Optics (Ro-FSO) can fulfil high-speed data demand in such locations without any such interference. However, the Ro-FSO performance is highly influenced by different adverse weather conditions, particularly haze and rainfall, which further cause attenuation in the transmission path of Ro-FSO systems. These atmospheric turbulences mainly affect the transmission link range of Ro-FSO systems. In this work, Ro-FSO system is designed by incorporating hybrid mode division multiplexing (MDM) and polarization division multiplexing (PDM) schemes to deliver four independent channels, each carrying 10 Gbps data upconverted to 40 GHz radio signal, over 3.4 km free space optical link operating under clear weather conditions. In addition to this, the proposed Ro-FSO link is subjected to different weather conditions, particularly partially hazy/rainy and dense fog/very rainy. The reported results indicate the achievement of acceptable bit error rate (BER≈10–3) for all channels up to 3400m FSO link under clear weather conditions, 1000m under partially haze/rain and 620 m under dense fog/heavy rain.


2012 ◽  
Vol 12 (5) ◽  
Author(s):  
Suriza Ahmad Zabidi ◽  
Md. Rafiqul Islam ◽  
Wajdi Al-Khateeb ◽  
Ahmed Wathik Naji

Free Space Optics (FSO) shows a great alternative as the solution for last mile problem where fiber optics is unavailable due to deployment time and cost constraint.  However, the feasibility of using FSO system as communication link very much depends on local weather.  Since tropical region experiences heavy rainfall, rain with high intensity is expected to affect the FSO link severely. Few prediction models have been proposed by ITU-R based on France and Japan’s measurement. This paper has compared  rain attenuation predicted by  models and  data measured in Malaysia over Free Space Optical links for one year period. Prediction models are clearly unable to predict attenuation measured in tropical climate. ABSTRAK: Wayarles optik menjadi alternatif sebagai satu penyelesaian kepada masalah kesesakan terutama diakhir sesuatu talian dimana ianya tidak dapat diselesaikan dengan menggunakan gentian fiber akibat daripada kekangan masa pemasangan dan masalah kewangan.  Walaubagaimanapun, kejayaan untuk menggunakan wayarless optic ini amat bergantung kepada keadaan cuaca di sesuatu tempat.  Di rantau tropika  hujan lebat sentiasa dialami, oleh itu hujan dengan kepadatan tinggi adalah dijangkakan lebih memberi kesan kepada talian wayarles optic ini. Beberapa model yang telah dicadangkan oleh ITU-R berlandaskan kepada pengumpulan data yang dibuat di Perancis dan Jepun.  Kertas kajian ini akan membandingkan antara model-model yang telah digunapakai dengan data yang dikumpulkan di Malaysia selama setahun.  Jelasnya model yang telah digunapakai tidak dapat digunakan secara berkesan di rantau tropika.KEYWORDS: free space optics; rainfall rate; rain attenuation


2018 ◽  
Vol 103 (2) ◽  
pp. 1603-1613 ◽  
Author(s):  
Govardhani Immadi ◽  
M. Venkata Narayana ◽  
Sarat K. Kotamraju ◽  
A. Sree Madhuri

Sign in / Sign up

Export Citation Format

Share Document