Supervisors info:
Εμμανουήλ X. Τσίλης, Επίκουρος Καθηγητής (Τμήμα Φυσικής ΕΚΠΑ)
Άννα N. Τζανακάκη, Επίκουρη Καθηγήτρια (Τμήμα Φυσικής ΕΚΠΑ)
Έκτορας Ε. Νισταζάκης, Αναπληρωτής Καθηγητής (Τμήμα Φυσικής ΕΚΠΑ) - κύριος επιβλέπων
Summary:
This master's thesis is about the study of the reflections effects on the performance of Visible Light Communication (VLC) systems with spatial modulation (eSSK) and four LED lamps illuminating the interior of a rectangular parallelepiped room with given dimensions.
Firstly, a geometrical computation model is developed for any possible reflection case, expanding the two-ray ground reflection model. By assuming virtual, straight rays going off the room instead of the real, indoor, crooked reflection rays with equal lengths, propagation distances and angles are calculated for any possible reflection case, each of which is uniquely identified by three integer indices l,m,n. Possible reflection cases cardinality formulas as a function of the reflection order are produced, assuming line-of-sight (LOS) rays case as a zero-order reflection. Moreover, the reflection spots on the room wall are determined precisely as well as the corresponting incidence/reflection angles.
Thereinafter, the Lambertian model is applied in order to compute the received power of any studied reflection ray and, after that, semi-analytic formulas are generated, in order to inductively compute the desired results. Some noise components, that further deteriorate the telecommunication system’s performance, are also referred. Furthermore, a received power computation algorithm structure is presented for any point of a horizontal plane of the studied room at a typical height above the floor.
Finally, the studied telecommunication system’s performance is evaluated by presenting 3-D plots, from which useful conclusions are drawn.
Keywords:
Indoor Communications; Visible Light Communications (VLC); LED lamps; Photodiode; Spatial modulation schemes; Enhanced Space Shift Keying (eSSK); Reflections; Reflection order; Line-of-Sight (LOS); Two-Ray ground reflected model; Lambertian model; Received power; Signal-to-Noise Ratio (SNR); Bit Error Rate (BER); Symbol Error Rate (SER); Computation algorithm; MATLAB code; 3-D plots.
