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- 2019
- FSO Communication System
- Subcarrier Intensity Modulation
- Atmospheric Turbulence
- Bit Error Rate
- Average Irradiance
- Optoelectronic Information Science and Engineering
- Galgotias College of Engineering and Technology
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[IEEE 2018 IEEE International Symposium on Local and Metropolitan Area Networks (LANMAN) - Washington, DC (2018.6.25-2018.6.27)] 2018 IEEE International Symposium on Local and Metropolitan Area Networks (LANMAN) - A Prototype of In-Band Full-Duplex Free-Space Optical Transceiver
摘要： Free-Space-Optical (FSO) communication has become an attractive option over Radio Frequency (RF) communication due to having broader bandwidth, unlicensed band, higher spatial reuse, and enhanced security. In-band full-duplex FSO (IBFD-FSO) transceivers ensure, in some cases enhance, these features enabling future vision of smart communication and Internet-of-Things (IoT) applications. Even though IBFD-FSO transceivers can double the network capacity theoretically, overall performance and capacity is limited by interference and optical feedback. In this paper, we present a proof-of-concept prototype of IBFD-FSO transceiver by implementing isolation technique to reduce optical feedback. We demonstrate the effectiveness of the isolation technique and performance through test-bed experiments using off-the-shelf components.
关键词： FSO,Optical Wireless,In-Band,Full-duplex
更新于2025-09-10 09:29:36
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Network Topology Reconfiguration for FSO-based Fronthaul/Backhaul in 5G+ Wireless Networks
摘要： Using free space optics (FSO) in the mobile fronthaul/backhaul networks is a promising solution that can potentially enhance the capacity of mobile networks. The main challenge of establishing FSO-based fronthaul/backhaul networks is the dynamic feature of the networks, i.e., the fragile links under adverse weather conditions and the dynamic traf?c demands among small cells. Topology recon?guration is proposed to dynamically rearrange the FSO links. In this paper, two types of network recon?gurations are investigated, in which the proactive network recon?guration is to proactively optimize the topology of the FSO-based fronthaul/ backhaul networks for each speci?c time period based on the statistics of the network, and the reactive recon?guration is to actively adjust the topology when traf?c demands and link states are changed. The proactive network recon?guration is formulated as a mixed integer nonlinear programming (MINLP) problem, which jointly optimizes the network throughput and power consumption of FSO-based fronthaul/backhaul networks. A greedy algorithm is proposed to derive the solution of the proposed problem. After the network topology having been recon?gured by solving the MINLP problem, two reactive recon?guration algorithms are designed to optimally adjust the network topology once a link failure and demand explosion occur, respectively, to further enhance the network throughput and reduce the power consumption. The performance of the algorithms is demonstrated via extensive simulations.
关键词： FSO-based fronthaul/backhaul,multi-criteria optimization,topology recon?guration,free space optics (FSO)
更新于2025-09-09 09:28:46
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Polar-Coded MIMO FSO Communication System Over Gamma-Gamma Turbulence Channel With Spatially Correlated Fading
摘要： In this paper, for the first time to the best of our knowledge, a polar-coded multiple-input multiple-output (MIMO) free space optical (FSO) communication system is proposed to combat turbulence-induced fading. Here, the spatially correlated fading, which dominates the MIMO FSO system aggravation, is taken into consideration in this polar-coded MIMO FSO system. To evaluate our scheme, the ergodic capacity of the gamma–gamma modeled MIMO FSO turbulence channel with and without spatially correlated fading is studied. The results of ergodic capacity and Monte Carlo simulation show that the polar-coded multiple photodetector scheme can effectively mitigate the fading induced by turbulence, and the polar-coded multiple optical sources scheme is robust to the spatially correlated turbulence. Further, more than 20 dB net coding gain (NCG) is achieved for the polar-coded MIMO FSO scheme in a strong turbulence condition with spatially correlated fading. Compared with low density parity check codes, polar codes achieve a 0.4–1.6 dB NCG improvement under a strong turbulence condition with and without spatially correlated fading, which verifies that our scheme is a promising candidate for combating turbulence-induced fading.
关键词： MIMO FSO,Gamma-gamma turbulence,Spatially correlated,Polar codes
更新于2025-09-09 09:28:46
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Analysis of selection combining scheme for hybrid FSO/RF transmission considering misalignment
摘要： This paper investigates the hybrid free-space optical (FSO)/radio frequency (RF) communication system under the selection combining (SC) diversity scheme. A benefit of this system is that it does not require channel-state information. The performance of the system is analyzed taking into consideration the fading effects and the pointing errors in this paper. The Nakagami-m model and the gamma–gamma model are adopted to describe the multipath effects of the RF link and the turbulence effects of the FSO link, respectively. The closed-form expressions of the outage probability and bit-error-rate (BER) are derived in this paper. The numerical simulations indicate that the hybrid FSO/RF system with SC is more reliable than the either RF link or FSO link, and it performs better than the hybrid system without SC.
关键词： Hybrid FSO/RF system,Selection combining,Misalignment
更新于2025-09-09 09:28:46
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[IEEE 2018 International Conference on Computer, Control, Electrical, and Electronics Engineering (ICCCEEE) - Khartoum (2018.8.12-2018.8.14)] 2018 International Conference on Computer, Control, Electrical, and Electronics Engineering (ICCCEEE) - Performance Evaluation of MIMO FSO Communication with Gamma-Gamma Turbulence Channel using Diversity Techniques
摘要： recently, Free Space Optical (FSO) communication has been evaluated in indoor and outdoor experimental environments for other communication applications, which opens the study of environmental effects in FSO communications, these effects represents the nature environments around us such as rain and fog, which are termed by mathematical distribution models such as lognormal and Gamma-gamma distribution. One of the major solutions that proposed to reduce these effects and enhance the received signal is the use of Multiple Input Multiple Output MIMO diversity techniques in FSO which is also considered in this study in addition to Gamma-Gamma turbulence channel. In this paper, a simulation based study is performed to evaluate Free Space Optics Communication FSOC which represents the latest technologies that implies the highest data rate links which is been used in more sensitive communication fields such as satellite communications. The results obtained from Matlab modeling. Simulations showed that better received signal can be achieved.
关键词： FSO,MIMO,diversity techniques,Gamma-Gamma
更新于2025-09-04 15:30:14
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Performance Analysis of Hybrid RF/FSO System using BPSK-SIM and DPSK-SIM over Gamma-Gamma Turbulence Channel with Pointing errors for Smart City Applications
摘要： The in wireless communication -Free space optics (FSO) offers lots of merits over radio frequency (RF) links due to its license free bandwidth, ease of installation, high security features, and viable cost for short distance communication. It's high speed data rate and immunity against Electromagnetic Interference (EMI) makes FSO the emerging technology of today. But, FSO is not always reliable especially during Atmospheric conditions like fog, rain, mist and snow. Hence, in account a new technique of Hybrid FSO/RF, this includes advantages of both FSO and RF technologies. Through this paper intend to perform an extensive analysis of the error and misalignment effects encountered in Line Of Sight (LOS) communication. Pointing error and turbulence effects are the main drawback parameters for our analysis. For this purpose I have taken into consideration different modulation techniques-Binary Phase Shift keying-Subcarrier Intensity Modulation (BPSK-SIM), Differential Phase Shift Keying- Subcarrier Intensity Modulation (DPSK-SIM) communication system with reference to OOK Modulation. The novel expressions for outage probability and BER for both FSO and RF system are derived which uses Rician Channel and 16QAM Modulation scheme alongside Hybrid FSO/RF system for weak, moderate, strong turbulence regimes using Meijer-G Function.
关键词： Free space optics,Hybrid RF/FSO,Gamma-Gamma Channel,Atmospheric turbulence
更新于2025-09-04 15:30:14
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[IEEE 2018 11th International Symposium on Communication Systems, Networks and Digital Signal Processing (CSNDSP) - Budapest (2018.7.18-2018.7.20)] 2018 11th International Symposium on Communication Systems, Networks & Digital Signal Processing (CSNDSP) - Modeling and Throughput Analysis of FSO Systems using GBN-ARQ and AR Transmission over Atmospheric Turbulence Channels
摘要： This paper addresses the error-control issue in free-space optical (FSO) communications. In particular, we model and analyze the throughput performance of FSO systems over atmospheric fading channel when the go-back-N (GBN) automatic repeat request (ARQ) and adaptive rate (AR) transmission schemes are employed. For this purpose, we first build the model to capture the time-varying behavior in atmospheric fading channels. We then use that channel model to develop the burst error model for GBN-ARQ with AR in order to analytically derive the system throughput. Numerical results quantitatively show the impacts of atmospheric turbulence on the throughput and confirm the effectiveness of the GBN/ARQ. Monte Carlo simulations are also performed to validate the analytical results.
关键词： throughput performance,go-back-N (GBN) automatic repeat request (ARQ),atmospheric turbulence,adaptive rate (AR) transmission,Free-space optical (FSO) communications
更新于2025-09-04 15:30:14