Electrical & Electronics Engineering

Permanent URI for this collectionhttp://197.211.34.35:4000/handle/123456789/131

Electrical & Electronics Engineering

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Author: search.filters.author.Ajiboye, Johnson AdegbengaEnd date: 2019

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    Spectrum Occupancy Measurement in the VHF Band- Results and Evaluation in the Context of Cognitive Radio
    (International Engineering Conference (IEC) 2019, 2019) Ajiboye, Johnson Adegbenga; Adegboye B.A; Aibinu A.M; Kolo J.G
    In this paper the results of spectrum occupancy survey in the context of Cognitive Radio was presented. In Cognitive Radio, secondary unlicensed users are allowed to opportunistically use the primary licensed users’ bands with the understanding that there will be no interference i.e Secondary Users (SU) quits at the arrival of Primary Users (PU). A 24-hour measurement survey was carried out at the centre of Minna metropolis in Niger State, Nigeria covering a frequency range of VHF (30-300MHz). Aaronia HF 6065 V4 spectrum analyzer was used for data collection. Results show that the band allocated for Aeronautical Navigation has the highest spectral occupancy of 39.83% followed by the FM band with occupancy of 12.90% while the frequency band meant for Aeronautical Mobile and Space Operation has occupancy of 4.73% and TV Broadcasting 0.09%. The average occupancy of the VHF band is 14.39%.
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    Review of Spectrum Occupancy Measurements in the Context of Cognitive Radio
    (IJIPC 2019, 2019-12) Ajiboye, Johnson Adegbenga; Babatunde Araoye Adegboye; Abiodun Musa Aibinu; Jonathan Gana Kolo
    Presently, there is a progressive growth in the proportion of internet users as well as deployment of data intensive applications which has led to higher demand for bandwidth on the usable spectrum space for the unlicensed and licensed frequency bands. Spectrum is a scarce and limited resource, inefficiencies in the management of spectrum has resulted to a recent and unique communication standard for explotting the current licensed spectrum in an opportunistic manner. Cognitive Radio (CR) has proved to be the solution to this seeming highly demanded spectrum Several studies have been conducted on spectrum occupancy across the world in order to observe and determine the bands that have been underutilized so as to make room for the new technological emergences such as CR. This review shows that from previous works done, there is a research gap in the spectrum measurement work for TV band and specifically the VHF band in Nigeria.
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    Cognitive Radio Networks, a Key Technology of Future Wireless Communication: Challenges and Opportunities
    (IUP Journal of Telecommunications, 2012-11-01) Ajiboye, Johnson Adegbenga; Yinusa Ademola Adediran
    It is a well-known and established fact that the current approach of fixed spectrum allocation, the command-and-control model, makes the spectrum or the finite resource to be grossly underutilized or inefficient. There are so many bands of the spectrum already licensed to users but which in reality are unoccupied at some instance in time thereby creating spectrum holes. These are 'opportunities' that could be harnessed. Cognitive Radio (CR) is a promising technology being envisioned to solve the problem of spectrum underutilization and allows for real-time spectrum management. The CR, in a non-interference basis, opportunistically explores the unused channel, thereby ensuring efficient usage of this 'scarce' resource. The CR is a sure technology for the next generation wireless systems. In a CR, a licensed user, also called a Primary User (PU), has a priority over the Secondary User (SU) which has no spectrum license. Therefore, at the arrival of a PU, an opportunistic SU vacates the occupied channel and seeks another empty channel to be allocated. In this way, spectral efficiency is greatly enhanced. In this work, we examine the challenges that this new technology is bound to face.
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    A Comparison of Code Maintainability in Agile Environment
    (IUP Journal of Information Technology, 2016-06-01) Mary Adebola Ajiboye; Matthew Sunday Abolarin; Ajiboye, Johnson Adegbenga
    The demand for quick delivery of quality software is becoming high among software clients due to the fast changing technology in the dynamic world. Agile software development meets this demand and has gained appropriate and wide acceptance among software practitioners. However, the quality of such software is greatly impacted by its maintainability. Unfortunately, existing works focused only on the flexibility aspect of maintainability without paying attention to timely delivery. In this work, maintainability as a function of time to correct codes was examined among various categories of software developers. Deliberate errors, ranging from two to nine, were introduced into sets of agile codes written in python programming language and given to 100 programmers, each in the groups of individual junior, individual expert, random, expert pairs, junior pairs and junior expert pairs. The results revealed that random pair programmers spent the highest time of 21.88 min/bug on the average, while individual experts spent the least time of 16.26 min/bug.