For an indoor non-directed line of sight optical wireless communication (NLOS-OWC) system we investigate the optimized Lambertian order (OLO) of light-emitting diodes (LEDs). We firstly derive an expression for the OLO from a conventional Lambertian LED model. Then, we analyze the indoor multi-cell NLOS-OWC channel characteristics including the optical power distribution and the multipath time ...

In wireless channel the noise has a zero mean. This channel property can be used in the enhancement of the noise performance in the digital receivers by oversampling the received signal and calculating the decision variable based on the time average of more than one sample of the received signal. The averaging process will reduce the effect of the noise in the decision variable that will approa...

Artificial neural network (ANN) has application in communication engineering in diverse areas such as channel equalization, channel modeling, error control code because of its capability of nonlinear processing, adaptability, and parallel processing. On the other hand, wavelet transform (WT) with both the time and the frequency resolution provides the exact representation of signal in both doma...

The physical transport methods used in wireless communication differ from wired communication. These differences affect how a secure channel can be established in a wireless environment. The purpose of this tutorial is to provide an overview of how a secure channel is set up in a wireless environment that uses the 802.11 or WAP standards.

In this paper, we analyze the secure connectivity in Shotgun cellular systems (SCS: Wireless communication systems with randomly placed base stations) by Poisson intrinsically secure communication graph (IS-graph), i.e., a random graph which describes the connections that are secure over a network. For a base-station in SCS, a degree of secure connections is determined over two channel models: ...

The second generation of digital video broadcasting (DVB-T2) standard utilizes orthogonal frequency division multiplexing (OFDM) system to reduce and to compensate the channel effects by utilizing its estimation. Since wireless channels are inherently sparse, it is possible to utilize sparse representation (SR) methods to estimate the channel. In addition to sparsity feature of the channel, the...

Communication traffic is vulnerable to timevariant wireless channel conditions such as: fading, time dispersive, or frequency dispersive distortion which can render nonadaptive communication processing ineffective. This paper surveys published wireless channel multistate hidden Markov models (HMM) revealing mature applications of HMMs and several approaches for modeling wireless channel paramet...