Muhammad Saadi

System demonstration for visible light communication using adaptive threshold detection for low data rate applications

With the materialization of light emitting devices for solid state lighting, visible light communication (VLC) has provided a prospect to realize low cost, high speed, power efficient and secure data transmission in addition to lighting. Incandescent and fluorescent light sources are being replaced by light emitting diodes (LED) which are not only energy efficient but also help in reducing carbon dioxide CO2 emission. In this paper, experimental results are being presented using a new protocol for VLC and the optimum placement of the LEDs within the transmitter to maximize the transmitter foot prints.

An LED Based Indoor Localization System Using k-Means Clustering

This paper introduces a novel visible light positioning (VLP) system using an un-supervised machine learning approach. Two transmitters consist of light emitting diodes (LEDs) which are modulated with 1 kHz and 2.5 kHz sinusoidal signals respectively. At the receiver end, the received signal strength (RSS) is calculated and a sparse grid/cube is constructed by measuring light intensity at different locations. A bilinear interpolation is then applied to create a dense grid of readings which is used for the training of a hierarchical k-means clustering system. For a given query LEDs reading, the trained clusters are used for position estimation by minimizing the distances between the readings and cluster centroids. Experimental results show that an average accuracy of 0.31m can be achieved for a room with the dimensions of 4.3 × 4 × 4 m3. We further compared the performance of two other clustering methods: k-medoids and fuzzy c-means however no significant improvement over the kmeans clustering is found.

Visible Light Communication – The Journey So Far

Abstract An unprecedented demand for connecting physical objects with the internet expedites the realization of internet of things, thus creating new challenges to explore new spectrums which are suitable for communication. Visible light communication (VLC) is one promising candidate not only to remove the spectrum crunch issues but also to offer virtually unlimited, unregulated spectrum. This paper discusses how VLC can help solving spectrum crunch, non-availability issues of radio frequency spectrum and how readily available spectrum of VLC can be utilized to cope up with the bandwidth requirements of next-generation networks. Furthermore, this paper also lists the technological innovations in the area of VLC from early days till present and its possible applications in various domains.

Efficient Medium Access Control Protocols for Broadband Wireless Communications

Suvit Nakpeerayuth1, Lunchakorn Wuttisittikulkij1, Pisit Vanichchanunt2, Warakorn Srichavengsup3, Norrarat Wattanamongkhol1, Robithoh Annur1, Muhammad Saadi4, Kamalas Wannakong1 and Siwaruk Siwamogsatham5 1Chulalongkorn University 2King Mongkuts University of Technology North Bangkok 3Thai-Nichi Institute of Technology 4University of Management and Technology 5National Electronics and Computer Technology Center 1,2,3,5Thailand 4Pakistan