Volume 31, Issue 1, July 2015

Applying Optimum Combining to a DS/CDMA Code Diversity System [Full Text] 

Hector Candiales and Shin’ichi Tachikawa

Abstract—In this paper, we propose a new weight coefficient calculation method for a DS/CDMA code-diversity system. The method is based on the well-known optimum combining theory, whereby the weight coefficient vector that maximizes output signal-to-interference plus noise ratio (SNIR) can be found by solving a linear system that involves an estimated interference- plus-noise correlation matrix. The method has two steps: first, estimating the interference-plus-noise correlation matrix; and second, solving the required linear system. We evaluate the proposed method using computer simulations, and show that it yields almost-equal bit error rate performance when compared to the previously proposed method: adaptive weight control. The result is expected, as an optimum combiner can also be implemented with an LMS adaptive array. Nevertheless, the proposed method has a couple of advantages; namely, being a direct (non-iterative) calculation method, and requiring a comparatively shorter training sequence. Its main drawback is the need to estimate the desired user’s power level at the receiver. The overhead caused by solving the linear system could be of concern, but becomes largely negligible compared to the training time if the receiver’s hardware is capable of many floating point operations per bit/symbol period. 


Programming Considerations for the Design of Token Ludo Game Using Petri Nets [Full Text] 

Bakpo, F.S, Ezugwu, O.A., and Ukekwe, E.C

Abstract— The behaviour of Petri nets with exponentially distributed firing times can be applied in modeling various real life systems such as communication protocols, workflow systems, etc. The interactive firing of transitions in subsequent markings is known as token game. This development is analogous to that of games of strategy, in which each player is assigned a set of possible strategies (actions or moves) and each possible combination of strategies, one for each player, produces an outcome. That is, player’s fortunes are intertwined and determined by change events. The design of an interactive Petri net-based token (ludo) game is presented in which transition firing is determined by dice cast. In this paper, we applied Petri nets in modeling the traditional ludo game. Programming is considered using object oriented system analysis and design methodology. 


Patient Monitoring Using Bluetooth and Wireless LAN: A Review [Full Text]

Obianuju Assumpta Ezugwu and Aneke Stephen

Abstract—There are several publications on health related issues, which are the primary concern of everybody. This paper is targeted at investigating and critically analyzing such publications which borders on Monitoring and Tracking of Hospital patients using Bluetooth and Wireless LAN. We looked at the technologies suggested in the research paper and found out the limitations and the areas that need to be improved upon. 


Optimization of Passive FTTH Network Design Using Vertical Micro Ducting [Full Text]

Mousaab M. Nahas

Abstract— This paper presents a simple, cost-effective fiber network design suitable for building FTTH technology in brownfield areas where buildings, roads, infrastructure etc. have already been constructed. The design employs vertical micro ducting system that is developed to eliminate damages in the existing infrastructure thus minimizing restoration costs. The design also ensures minimal deployment time hence public disturbance. We believe that the major cost saving in FTTH technology is achieved through optimizing the outside plant network design as demonstrated in this research.