As the spectrum for wireless transmission gets crowded due to the increase in the users and applications, the efficient use of the spectrum is a major challenge in today’s world. A major affecting factor is the inefficient usage of the frequency bands. Interference in the neighboring cells affects the reuse of the frequency bands. In this paper, some of the quality of service parameters such as...

An assessment of spectrum efficiency for a microcellular land mobile radio system is presented by considering the desired signal as (fast) Rician fading with (slow) lognormal shadowing and co-channel interfering signals as uncorrelated (fast) Rayleigh fading superimposed over (slow) lognormal shadowing. Spectrum efficiency is defined in terms of reuse distance, Le., cluster size, traffic intens...

This paper presents a novel framework to optimally solve the spectrum access problem at the central spectrum moderator (CSM) for multiple radio pairs. In the system model considered, the available spectrum is partitioned into N subcarriers, and the proposed CSM assigns subcarriers to multiple radio pairs with the objective to maximize the total achievable bit rate in the network. Each transceiv...

Compared to current mobile networks, nextgeneration mobile networks are expected to support higher numbers of simultaneously connected devices and to achieve higher system spectrum efficiency and lower power consumption. To achieve these goals, we study the multi-sharing device-todevice (D2D) communication, which allows any cellular user equipment to share its radio resource with multiple D2D d...

As cellular network technology evolves, the operators deploy new generation networks while maintaining their legacy networks, since not all users upgrade their terminals at the same pace. Therefore, the spectrum associated to these legacy networks becomes gradually underused. By means of cognitive radio techniques, the operator can allow its new generation terminals to reuse this spectrum. We p...

Cognitive Radios have been receiving increasing attention in academia, industry, and government. This has come after several studies indicating that up to 90% of the allocated radio spectrum less than 3GHz is idle most of the time [1]. As a result, spectrum regulation around the world is in progress to allow unlicensed access on a non-interfering [2] [3]. Current researches are investigating di...

The techniques to recycle and reuse plastics attract public attention. These public attraction and needs result in improving the recycling technique. However, the identification technique for black plastic wastes still have big problem that the spectrum extracted from near infrared radiation spectroscopy is not clear and is contaminated by noise. To overcome this problem, we apply Raman spectro...

Software component-based reuse is diÆcult for software developers to adopt because rst they must know what components exist in a reuse repository and then they must know how to retrieve them easily. This paper describes the concept and implementation of active reuse repository systems that address the above two issues. Active reuse repository systems employ active information delivery mechanism...

In this contribution, we investigate the idea of using cognitive radio to reuse locally unused spectrum to increase the total system capacity. We consider a multiband/wideband system in which the primary and cognitive users wish to communicate to different receivers, subject to mutual interference and assume that each user knows only his channel and the unused spectrum through adequate sensing....