Title
Using differential signalling to mitigate pointing errors effect in FSO communication link
Abstract
In this paper, we investigate a differential signalling (DS) scheme to mitigate pointing errors effect in intensity-modulation/direct-detection (IM/DD) free space optical (FSO) communication systems with the non-return-to-zero on-off keying (NRZ-OOK) modulation format. The most common approach to detect a digital signal is based on comparing the received signal with an optimal threshold level. Normally, this optimal threshold level is set at the mean value of the signal in a clear channel. However, this detection threshold method is inefficient in a channel with fading effects. DS has been reported to mitigate the fluctuation of optimal detection threshold in NRZ-OOK IM/DD FSO communication systems only to combat atmospheric fading effects (e.g., fog and turbulence) and to reduce the background noise of the received signal. In this paper, we adopt the DS scheme to mitigate the optimal detection threshold level fluctuations induced by pointing errors. We also discuss the conditions in which DS cancels out the fluctuation of threshold level. The proposed technique is supported by carrying out experimental investigation of the FSO link with pointing errors. Measured results confirm that the effect of PE on the received signal was highly correlated (i.e., ρ = 0.92, where ρ is the correlation coefficient between channels) thus resulting in reduced variance value of the combined signal threshold level. We also derive an expression for bit-error-rate for the system which is supported by simulation.
Year
DOI
Venue
2016
10.1109/ICCW.2016.7503779
2016 IEEE International Conference on Communications Workshops (ICC)
Keywords
Field
DocType
Optical communication,free space optics (FSO),threshold detection,pointing errors
Telecommunications,Background noise,Optical communication,Digital signal,Computer science,Fading,Control theory,Keying,Communications system,Communication channel,Modulation,Real-time computing
Conference
ISSN
ISBN
Citations 
2164-7038
978-1-5090-0449-2
1
PageRank 
References 
Authors
0.42
5
6
Name
Order
Citations
PageRank
Mojtaba Mansour Abadi163.99
Zabih Ghassemlooy230485.69
Manav R. Bhatnagar353953.01
S. Zvanovec45932.45
Mohammad Ali Khalighi56012.87
Alireza Maheri641.55