Volume 31, Issue 2, August 2015

System Model of TH-UWB Using LDPC Code Implementation [Full Text]

M. Marjanović-Jakovljević

Abstract— A Low-Density Parity- Check (LDPC) code is an error-correcting code in a noisy-channel transmission that closely approaches the Shannon limit, also called channel capacity. Time Hopping-Ultra Wideband (TH-UWB) is a relatively new technology that might have a huge impact on improving wireless communications. Since that current TH-UWB systems apply convolutional codes as their channel coding scheme, it is very usefull to investigate LDPC codes performance for those systems. This paper presents a mathematical model in order to simulate TH-UWB systems with LDPC code implementation. Using this implementation, it is shown that for low Signal to Noise Ratio (SNR) in the real multipath channel environment, the difference between LDPC coded and non-coded system is negligible, but for BER=10-3, the gain of the coded system compared to the non-coded system is approximately 4 dB. Owing to this implementation, in this accurate and flexible system model, BER performance of a TH-UWB System in different scenarios is presented and good performance in terms of BER versus SNR is achieved. An additional result is the validation of the simulated results with performance formula for TH-UWB systems when LDPC is implemented. 


Micro Controller Based Remote Sensing and Controlling using Cellular Network [Full Text] 

Gazi Mohammad Sharif and Khosru Mohammad Salim

Abstract—Remote sensing and controlling play vital roles for communications, especially for far distance and where the physical contacts are difficult. Microcontroller is a powerful device, which has the computing ability, anda tiny and cheap microcontroller can be used for various important techniques. On the other hand, cellular networks cover very far distance and provide smooth connections all over the world. Remote sensing through cellular networks are very effective as objects do not need to be line of sight and any device can be controlled remotely from one part to another part of the world. In this paper, a simple microcontroller based remote sensing and controlling technique has been demonstrated using the cellular networks.