Performance evaluation of AF-relayed mixed FSO/mm-wave-RF link modeled by generalized misalignment and RF fading distributions

Frequenz ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Himanshu Khanna
Keyword(s):  
Wireless Channels ◽  
Path Loss ◽  
Multipath Fading ◽  
Cumulative Distribution ◽  
60 Ghz ◽  
Free Space Optical ◽  
Amplify And Forward ◽  
Error Performance ◽  
Multiuser Transmission ◽  
Vertical Displacements

AbstractThe performance of a generalized mixed free-space-optical (FSO)/millimeter (mm)-wave radio-frequency (RF) two-hop link model is investigated in this work. The first-hop FSO channel considers the influence of path loss, atmospheric turbulence which is modeled by the gamma–gamma (GG)-distribution, and generalized misalignment errors which incorporate the effects of non-zero boresight errors, different jitter standard deviations along the horizontal and vertical directions, and correlation between the horizontal and vertical displacements. The second-hop RF link is modeled by an extended-generalized-K (EGK) distribution which is a versatile distribution and can characterize various fading conditions in mm-wave wireless channels where the transmission frequency is in excess of 60 GHz, and considers non-homogeneous propagation, interference effects due to multiuser transmission, multipath fading and shadowing effects observed in mm-wave RF wireless channels. The considered system employs fixed-gain amplify-and-forward (AF) relay-assisted transmission. The statistical characteristic for the end-to-end SNR, i.e., cumulative distribution function (cdf), is obtained for the considered system model in this work. Based on the obtained result for cdf, the outage and error performance is evaluated, and closed form expressions for the same are derived. The derived analytical results have been illustrated through numerical plots.

Performance Analysis of an Inter-Relay Co-operation in FSO Communication System

2018 ◽  
Vol 39 (2) ◽  
pp. 199-208
Author(s):  
Himanshu Khanna ◽  
Mona Aggarwal ◽  
Swaran Ahuja
Keyword(s):  
Path Loss ◽  
System Model ◽  
Line Of Sight ◽  
Destination Node ◽  
System Configuration ◽  
Free Space Optical ◽  
Error Performance ◽  
Probability Of Error ◽  
Pointing Error ◽  
Significant Performance

AbstractIn this work, we analyze the outage and error performance of a one-way inter-relay assisted free space optical link. The assumption of the absence of direct link between the source and destination node is being made for the analysis, and the feasibility of such system configuration is studied. We consider the influence of path loss, atmospheric turbulence and pointing error impairments, and investigate the effect of these parameters on the system performance. The turbulence-induced fading is modeled by independent but not necessarily identically distributed gamma–gamma fading statistics. The closed-form expressions for outage probability and probability of error are derived and illustrated by numerical plots. It is concluded that the absence of line of sight path between source and destination nodes does not lead to significant performance degradation. Moreover, for the system model under consideration, interconnected relaying provides better error performance than the non-interconnected relaying and dual-hop serial relaying techniques.

COOPERATIVE RELAY PROTOTYPE DEVELOPMENT AND PERFORMANCE MEASUREMENT

2015 ◽  
Vol 77 (10) ◽  
Author(s):  
Igbafe Orikumhi ◽  
Muhammad Rushidi Sabirin ◽  
Chee Yen Leow
Keyword(s):  
Power Efficiency ◽  
System Development ◽  
Software Radio ◽  
Path Loss ◽  
Multipath Fading ◽  
Cooperative Relaying ◽  
Cooperative Relay ◽  
Communication Link ◽  
Amplify And Forward ◽  
Prototype Development

To meet the demand for high data rate, the wireless cellular system technology has grown in a steady pace in recent years. However, due to multipath fading, shadowing effects and path loss, the wireless communication links are prone to errors. To improve the communication link, at the cell edge and shadowed environment, cooperative relaying scheme has been proposed. In cooperative relaying, an additional node is placed between the source and destination terminals, to provide redundant path for data transmission. However, existing literature on cooperative relaying only investigates the system performance through theoretical simulations. The real world performance remains unknown because of the lack of prototypes for field testing and measurement. This work focuses on the development of an amplify-and-forward (AF) cooperative relaying prototype. The prototype is developed using the LabVIEW system development platform and the implementations are carried out on Universal Software Radio Peripheral (USRP). The performance of the AF based cooperative relaying prototype is measured in terms of the bit error rate (BER) and compared with the direct communication link without relay. The measured results show that cooperative relay assisted communication achieves significant improvement in terms of signal reliability, coverage distance and power efficiency.

BER performance analysis of FSO using hybrid-SIM technique with APD receiver over weak and strong turbulence channels

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rajat Kumar Giri
Keyword(s):  
Performance Improvement ◽  
System Performance ◽  
Avalanche Photodiode ◽  
Free Space Optical ◽  
Error Performance ◽  
Strong Turbulence ◽  
Meijer G Function ◽  
Hermite Approximation ◽  
Ber Performance ◽  
Better Than

Abstract In this paper, a hybrid-subcarrier-intensity-modulation (hybrid-SIM) technique for the performance improvement of free-space-optical (FSO) communication system has been proposed. Subsequently, for further error performance improvement, avalanche photodiode (APD) based receiver is used in the proposed system. The system performance is analyzed at various atmospheric turbulence levels over weak and strong turbulence channels. The bit error rate (BER) is theoretically derived using Gauss–Hermite approximation and Meijer-G function and it is simulated in the MATLAB environment. The simulation result shows that the BER performance of hybrid-SIM is better than BPSK-SIM technique irrespective of the channel types and also the significant BER performance improvement is observed by APD receiver.

An investigation of 16-QAM signal transmission over turbulent RoFSO link modeled by gamma–gamma distribution

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Abhishek Tripathi ◽  
Shilpi Gupta ◽  
Abhilash Mandloi ◽  
Gireesh G Soni
Keyword(s):  
Gamma Distribution ◽  
Free Space ◽  
Signal Transmission ◽  
Channel Modeling ◽  
Symbol Error Rate ◽  
Average Error ◽  
60 Ghz ◽  
Free Space Optical ◽  
Error Vector Magnitude ◽  
Space Optical Communication

AbstractThis paper outlines the performance of a 10 Gbit/s rectangular 16-quadrature amplitude modulation–based radio over free space optical communication system. Here, 60 GHz radio frequency–modulated signal is propagated through a 1550-nm free space optical link. The gamma–gamma distribution is used for the channel modeling of weak to strong atmospheric turbulence. The reported constellation plots and eye patterns are attributed to impairment factors in adverse conditions of atmosphere. The evaluation is carried out that the variation in average error vector magnitude in the range of 1.45–1.63% and equivalent symbol error rate of 0.019–0.023 are obtained for a clear atmosphere compared to the turbulent link of 0.2–1 km, respectively.

Elevation-angle based two-ray path loss model for Air-to-Ground wireless channels

2021 ◽  
pp. 100393
Author(s):  
N.H. Ranchagoda ◽  
K. Sithamparanathan ◽  
M. Ding ◽  
A. Al-Hourani ◽  
K.M. Gomez
Keyword(s):  
Wireless Channels ◽  
Elevation Angle ◽  
Path Loss ◽  
Loss Model ◽  
Path Loss Model ◽  
Ray Path

scholarly journals Performance Analysis of Hybrid Radio Frequency and Free Space Optical Communication Networks with Cooperative Spectrum Sharing

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 108
Author(s):  
Dong Qin ◽  
Yuhao Wang ◽  
Tianqing Zhou
Keyword(s):  
Radio Frequency ◽  
Communication Networks ◽  
Free Space ◽  
Spectrum Sharing ◽  
Cumulative Distribution ◽  
Free Space Optical ◽  
Secondary Users ◽  
Primary Users ◽  
Cooperative Spectrum Sharing ◽  
The Impact

This paper investigates the impact of cooperative spectrum sharing policy on the performance of hybrid radio frequency and free space optical wireless communication networks, where primary users and secondary users develop a band of the same spectrum resource. The radio frequency links obey Nakagami-m distribution with arbitrary fading parameter m, while the free space optical link follows gamma-gamma distributed atmospheric turbulence with nonzero pointing error. Because the secondary users access the spectrum band without payment, their behavior needs to be restricted. Specifically, the power of the secondary users is dominated by the tolerable threshold of the primary users. Considering both heterodyne and intensity modulation/direct detection strategies in optical receiver, the performance of optical relaying networks is completely different from that of traditional networks. With the help of bivariable Fox’s H function, new expressions for cumulative distribution function of equivalent signal to noise ratio at destination, probability density function, outage probability, ergodic capacity and symbol error probability are built in closed forms.

scholarly journals Propagation Path Loss Modeling and Outdoor Coverage Measurements Review in Millimeter Wave Bands for 5G Cellular Communications

2018 ◽  
Vol 8 (4) ◽  
pp. 2254 ◽  
Author(s):  
Mohammed B. Majed ◽  
Tharek A. Rahman ◽  
Omar Abdul Aziz
Keyword(s):  
Communication Networks ◽  
Millimeter Wave ◽  
Wide Spectrum ◽  
Path Loss ◽  
Separation Distance ◽  
Propagation Path ◽  
Delay Spread ◽  
Propagation Time ◽  
60 Ghz ◽  
Rms Delay Spread

The global bandwidth inadequacy facing wireless carriers has motivated the exploration of the underutilized millimeter wave (mm-wave) frequency spectrum for future broadband cellular communication networks, and mmWave band is one of the promising candidates due to wide spectrum. This paper presents propagation path loss and outdoor coverage and link budget measurements for frequencies above 6 GHz (mm-wave bands) using directional horn antennas at the transmitter and omnidirectional antennas at the receiver. This work presents measurements showing the propagation time delay spread and path loss as a function of separation distance for different frequencies and antenna pointing angles for many types of real-world environments. The data presented here show that at 28 GHz, 38 GHz and 60 GHz, unobstructed Line of Site (LOS) channels obey free space propagation path loss while non-LOS (NLOS) channels have large multipath delay spreads and can utilize many different pointing angles to provide propagation links. At 60 GHz, there is more path loss and smaller delay spreads. Power delay profiles PDPs were measured at every individual pointing angle for each TX and RX location, and integrating each of the PDPs to obtain received power as a function of pointing angle. The result shows that the mean RMS delay spread varies between 7.2 ns and 74.4 ns for 60 GHz and 28 GHz respectively in NLOS scenario.

scholarly journals Average Channel Capacity of Amplify-and-forward MIMO/FSO Systems Over Atmospheric Turbulence Channels

2018 ◽  
Vol 8 (6) ◽  
pp. 4334
Author(s):  
Duong Huu Ai
Keyword(s):  
Atmospheric Turbulence ◽  
Channel Capacity ◽  
Multiple Input Multiple Output ◽  
Mathematical Expression ◽  
Relay Channel ◽  
Free Space Optical ◽  
Amplify And Forward ◽  
Average Channel Capacity ◽  
Link Distance ◽  
Gamma Distributions

In amplify-and-forward (AF) relay channel, when the direct link between source and destination terminals is deeply faded, the signal from the source terminal to the destination terminal propagates through the relay terminals, each of which relays a signal received from the previous terminal to the next terminal in series. This paper, we theoretically analyze the performance of multiple-input multiple-output (MIMO) AF free-space optical (FSO) systems. The AF-MIMO/FSO average channel capacity (ACC), which is expressed in terms of average spectral efficiency (ASE) is derived taking into account the atmospheric turbulence effects on the MIMO/FSO channel. They are modeled by log-normal and the gamma-gamma distributions for the cases of weak-to-strong turbulence conditions. We extract closed form mathematical expression for the evaluation of the ACC and we quantitatively discuss the influence of turbulence strength, link distance, different number of relay stations and different MIMO configurations on it.

scholarly journals BER analysis of amplify-and-forward relaying FSO systems using APD receiver over strong atmospheric turbulence channels

2019 ◽  
Vol 9 (5) ◽  
pp. 3678
Author(s):  
Duong Huu Ai ◽  
Van Loi Nguyen
Keyword(s):  
Atmospheric Turbulence ◽  
Closed Form Expression ◽  
Free Space Optical ◽  
Amplify And Forward ◽  
Transmission Distance ◽  
Link Distance ◽  
Optimal Value ◽  
Atmospheric Loss ◽  
The Impact ◽  
Relay Stations

<span lang="EN-US">In this paper, we theoretically analyze the performance of amplify-and-forward (AF) serial relaying free-space optical (FSO) systems using avalanche photodiodes (APD) and subcarrier quadrature amplitude modulation (SC-QAM) over strong atmospheric turbulence channels modelled by gamma-gamma distribution. Closed-form expression for average bit error rate (BER) of system is theoretically derived talking into account APD shot noise, thermal noise as well as the impact of atmospheric loss and turbulence. The numerical results show that using AF relay stations can extend the transmission distance and help to improve performance of FSO system significantly when compared with the direct transmission. Moreover, the selection of APD gain value is indispensable to the system performance. The proposed system could be achieved the best performance by selecting an optimal APD gain value. In addition, the optimal value of APD gain also significantly depends on various conditions, such as link distance, the number of relay stations and APD receiver noise.</span>

Sign in / Sign up

Export Citation Format

Share Document