R Badlishah Ahmad
Thumbnail Image
Preferred name
R Badlishah Ahmad
Official Name
R Badlishah, Ahmad
Alternative Name
Ahmad, R. Badlishah
Ahmad, B.
Badlishah Ahmad, R.
Ahmad, Rashidi
Ahmad, Badlisha
Ahmed, R. Badlishah
Ahmad, R. B.
Badlishah, R.
Ahmad, R. Badli
Ahmed, Rbadlishah
Main Affiliation
Scopus Author ID
57194844651
Researcher ID
U-3211-2019

Research Output

Filters

2 2
2
Reset filters

Settings
Now showing 1 - 2 of 2
  • Publication
    Enhanced experimental investigation of threshold determination for efficient channel detection in 2.4 GHz WLAN cognitive radio networks
    ( 2017-09-01)
    Mohammad Nayeem Morshed
    ;
    Sabira Khatun
    ;
    Latifah Munirah Kamarudin
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    R Badlishah Ahmad
    ;
    Ammar Zakaria
    ;
    Md. Moslemuddin Fakir
    This paper presents an experimental investigation of threshold determination for efficient channel detection in wireless LAN (WLAN) based cognitive radio (CR) networks. The spectrum saturation problem is a critical issue in wireless communication systems worldwide due to on growing user demands day by day with many new applications to the limited frequency spectrum. Hence, present demand is an efficient and intelligent spectrum management and allocation system. In this paper, we proposed an adaptive threshold determination technique based on free space path loss (FSPL) model to detect the presence or absence of PUs. The model is designed especially for Android based smartphones and tablets. The smartphones act as secondary users (SUs) and existing 2.4 GHz WLAN channels as PUs. The network is prepared in a usual noisy lab/outdoor environment and tested for the robustness of the proposed model. Results show the desired range of usable threshold and the channel detection performance depends on the noise floor level of the surrounding environment.
  • Publication
    Adaptive threshold determination for efficient channel sensing in cognitive radio network using mobile sensors
    ( 2017-03-13)
    Mohammad Nayeem Morshed
    ;
    Sabira Khatun
    ;
    Latifah Munirah Kamarudin
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    R Badlishah Ahmad
    ;
    Ammar Zakaria
    ;
    Moslem Fakir
    Spectrum saturation problem is a major issue in wireless communication systems all over the world. Huge number of users is joining each day to the existing fixed band frequency but the bandwidth is not increasing. These requirements demand for efficient and intelligent use of spectrum. To solve this issue, the Cognitive Radio (CR) is the best choice. Spectrum sensing of a wireless heterogeneous network is a fundamental issue to detect the presence of primary users' signals in CR networks. In order to protect primary users (PUs) from harmful interference, the spectrum sensing scheme is required to perform well even in low signal-to-noise ratio (SNR) environments. Meanwhile, the sensing period is usually required to be short enough so that secondary (unlicensed) users (SUs) can fully utilize the available spectrum. CR networks can be designed to manage the radio spectrum more efficiently by utilizing the spectrum holes in primary user's licensed frequency bands. In this paper, we have proposed an adaptive threshold detection method to detect presence of PU signal using free space path loss (FSPL) model in 2.4 GHz WLAN network. The model is designed for mobile sensors embedded in smartphones. The mobile sensors acts as SU while the existing WLAN network (channels) works as PU. The theoretical results show that the desired threshold range detection of mobile sensors mainly depends on the noise floor level of the location in consideration.