Baze University

NAJASHI GAFAI


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  • Qualifications: No Qualification Found
  • Role Title: HOD
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  • Email: najashi.gafai@bazeuniversity.edu.ng
  • Department: No Department Name
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I hold a Bachelor of Engineering (B.Eng) from Ahmadu Bello University Zaria in 2009. I proceeded to Chongqing University in Chongqing Municipality, China for M.Eng and Ph.D. in Information and Communication Engineering from 2009 to 2014. My research interest revolves around dynamic spectrum access, machine learning, and data analytics. I am a registered member with COREN and IAENG.

Sorry no Qualification(s) Information found
Module Code Module Description Credit Unit
CME501 Artificial Neural Network 3
EEE303 Electromagnetic Fields and Waves I 3
EEE306 Digital Electronic Circuit 3
EEE307 Analogue Electronic Circuit 3
EEE401 Control Systems 3
EEE403 Numerical Methods II 2
EEE503 Control Engineering 3
TLE401 Digital Devices and Logic Circuits 3
TLE407 Telecommunication Engineering 2
TLE503 Digital Communication System 3
TLE507 Communication Systems Planning 2

My primary research interest currently centers on a dynamic approach to spectrum allocation whereby licensed and unlicensed users can share the spectrum/channel without interference. Studies (including mine done in Abuja) have shown that the spectrum allocated using the command and control approach is not fully utilized. In most cases, not up 25% is utilized. This major finding has led to the concept of cognitive radio/dynamic spectrum access. The aims of spectrum occupancy measurements have broadened to include quantitative information on underutilized spectrum bands for possible cognitive radio deployment and also the establishment of the degree of efficiency of spectrum usage. The economic and research communities might have different motives for conducting a spectrum occupancy measurement, with the economic community mostly interested in the investments required to develop cognitive radio so that the investments are not misapplied if they do not take into account the current realities. On the other hand, the research community is most interested in determining the bands that experience low utilization so that they can be analyzed and characterized in time, frequency and space. This information will be vital for the deployment of future cognitive radio systems.

 

At the moment I have conducted several spectrum occupancy measurements to determine spectrum utilization and also find spectrum holes that can be shared with a secondary user. During my Ph.D. program, I was able to generate over 2GB of spectrum occupancy data. The data was generated from two locations; Abuja and Katsina. In-depth analysis of the generated data was performed including spectral and temporal analysis. One of the significant components of dynamic access architecture is the ability to predict spectrum holes based on historical data. I was able to develop a neural network-based model using the data generated during the spectrum occupancy measurements campaign. The model recorded an observed mean prediction error of about 0.005 in some cases. Several improvements have been made in order to improve its prediction accuracy like using data from two or more devices in a cooperative manner.

    Journal


  1. American Journal Of Engineering and Applied Sciences

    Authors: Najashi Gafai, Tan Xiaoheng
    Journal Title: A Comparative Performance Analysis of Multiple-Input Multiple-Output using MATLAB with Zero Forcing | Journal Number: 4 | Volume Number: 3 | Page Range: 425-428

    DOI: https://pdfs.semanticscholar.org/0b6d/ed3a7f95cba97f075a24b97b7d4d39e3f23e.pdf | Database: Science Publisher | Year: 2011

  2. International Journal of Computer Science Issues

    Authors: Najashi Gafai, Feng Wenjiang, Mohammed Dikko Almustapha
    Journal Title: Spectrum Hole Prediction Based On Historical Data: A Neural Network Approach | Journal Number: 10 | Volume Number: 0 | Page Range:

    DOI: https://arxiv.org/abs/1401.0886 | Database: Google Scholar, Sensei, arvix.org etc | Year: 2013

  3. International Journal of Computer Science Issues

    Authors: Najashi Gafai, Feng Wenjiang, Choiabu Kadri
    Journal Title: An Insight into Spectrum Occupancy in Nigeria | Journal Number: 10 | Volume Number: 0 | Page Range:

    DOI: https://ijcsi.org/papers/IJCSI-10-1-1-394-399.pdf | Database: Google Scholar, Sensei, arvix.org etc | Year: 2013

  4. Journal of Computational Information Systems

    Authors: Najashi Gafai, Feng Wenjiang
    Journal Title: Cooperative Spectrum Occupancy Based Spectrum Prediction Modeling | Journal Number: 0 | Volume Number: 10 | Page Range:

    DOI: | Database: EI INDEX | Year: 2014

  5. International Journal of Computer Science Issues

    Authors: Najashi Gafai, Feng Wenjiang, Abdiaziz Sheik Abdi, Abubakar A. Mustapha
    Journal Title: Spectrum Occupancy Measurements in Nigeria: Results and Analysis | Journal Number: 15 | Volume Number: 0 | Page Range:

    DOI: http://www.ijcsi.org/papers/IJCSI-12-4-156-165.pdf | Database: Google Scholar, Sensei, arvix.org etc | Year: 2015