Performance analysis and mitigation of turbulence effects using spatial diversity techniques in FSO systems over combined channel

Author(s):  
Prabu Krishnan
2020 ◽  
Vol 113 (3) ◽  
pp. 1541-1565 ◽  
Author(s):  
Isiaka A. Alimi ◽  
Romilkumar Kantibhai Patel ◽  
Nelson Jesus Muga ◽  
Paulo P. Monteiro

2019 ◽  
Vol 40 (3) ◽  
pp. 307-314 ◽  
Author(s):  
Rajat Kumar Giri ◽  
Bijayananda Patnaik

Abstract In this paper, we study the performance improvement of free space optical (FSO) communication system with spatial diversity techniques employing hybrid pulse position modulation-binary phase shift keying-subcarrier intensity modulation (PPM-BPSK-SIM). The involvement of multiple photo-detectors in diversity based FSO systems offers an effective way to overcome scntillation. In this paper, we have simulated the bit error rate (BER) with respect to different parameters like average SNR, link distance at various weather conditions. The simulation results are verified in Matlab environment with the mathematical analysis. The simulation results show that higher order single input multiple output (SIMO) system achieves better BER performance and hybrid PPM-BPSK-SIM has significant improved performance than the common modulation schemes like PPM, BPSK-SIM.


2014 ◽  
Vol 34 (1) ◽  
pp. 0106001 ◽  
Author(s):  
王翔 Wang Xiang ◽  
赵尚弘 Zhao Shanghong ◽  
郑光威 Zheng Guangwei ◽  
李勇军 Li Yongjun ◽  
楚兴春 Chu Xingchun ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Sheeraz Ahmed ◽  
Nadeem Javaid ◽  
Ashfaq Ahmad ◽  
Imran Ahmed ◽  
Mehr Yahya Durrani ◽  
...  

Reliability is a key factor for application-oriented Underwater Sensor Networks (UWSNs) which are utilized for gaining certain objectives and a demand always exists for efficient data routing mechanisms. Cooperative routing is a promising technique which utilizes the broadcast feature of wireless medium and forwards data with cooperation using sensor nodes as relays. Here, we present a cooperation-based routing protocol for underwater networks to enhance their performance called Stochastic Performance Analysis with Reliability and Cooperation (SPARCO). Cooperative communication is explored in order to design an energy-efficient routing scheme for UWSNs. Each node of the network is assumed to be consisting of a single omnidirectional antenna and multiple nodes cooperatively forward their transmissions taking advantage of spatial diversity to reduce energy consumption. Both multihop and single-hop schemes are exploited which contribute to lowering of path-losses present in the channels connecting nodes and forwarding of data. Simulations demonstrate that SPARCO protocol functions better regarding end-to-end delay, network lifetime, and energy consumption comparative to noncooperative routing protocol—improved Adaptive Mobility of Courier nodes in Threshold-optimized Depth-based routing (iAMCTD). The performance is also compared with three cooperation-based routing protocols for UWSN: Cognitive Cooperation (Cog-Coop), Cooperative Depth-Based Routing (CoDBR), and Cooperative Partner Node Selection Criteria for Cooperative Routing (Coop Re and dth).


2018 ◽  
Vol 39 (3) ◽  
pp. 349-357 ◽  
Author(s):  
Rahul Kaushik ◽  
Vineet Khandelwal ◽  
R.C. Jain

Abstract In this paper, average channel capacity of optical wireless communication system is evaluated under the combined effect of geometrical loss, attenuation due to weather conditions and weak atmospheric turbulence using a simple closed form expression. Fading induced due to atmospheric turbulence is modeled by log-normal distribution. Considering the fact that the sum of log-normal random variables can be well approximated by another log-normal random variable, the proposed expression has been utilized to compute the channel capacity for spatial diversity reception employing maximum ratio combining and equal gain combining over uncorrelated turbulence-induced fading conditions. It is shown that spatial diversity is an effective technique to mitigate the impairments caused by various atmospheric conditions such as haze, rain and fog. The quantitative improvement in channel capacity achieved by using diversity techniques is investigated and compared. Accuracy of the results is validated with exact results computed using Monte Carlo simulation.


Sign in / Sign up

Export Citation Format

Share Document