The rising number and capacity requirements of wireless systems bring increasing demand for RF spectrum. Cognitive radio (CR) system is an emerging concept to increase the spectrum efficiency. CR system aims to enable opportunistic usage of the RF bands that are not occupied by their primary licensed users in spectrum overlay approach. In this approach, the major challenge in realizing the full...

The rising number and capacity requirements of wireless systems bring increasing demand for RF spectrum. Cognitive radio (CR) system is an emerging concept to increase the spectrum efficiency. CR system aims to enable opportunistic usage of the RF bands that are not occupied by their primary licensed users in spectrum overlay approach. In this approach, the major challenge in realizing the full...

In cognitive radio, secondary users wittily occupy the spectrum hole and enhance the efficiency at the right location and time. Secondary users reward a chance to access primary user band with the aid of smart cognitive radio technology. In this study we explore the idea of secondary access spectrum through using the cognitive radio network in which the secondary user shares the spectrum with t...

This paper investigates a new spectrum sharing algorithm based on price in cognitive radio networks. A supply and demand model between primary users and secondary users is established to decide the price of free spectrum leased by primary users. Considering the utility of primary users and the total bandwidth while deciding the price per bandwidth using supply and demand balance (the spectrum s...

When we consider a spectrum sharing networks it have primary user and secondary user. Spectrum share by the first user is called primary user. Primary user used the allocated spectrum without affected any interference. But in the case of secondary user used the primary user spectrum it has much interference occur, also need more emitted power. xG networks are envisioned to provide opportunistic...

Radio spectrum is becoming increasingly scarce as more and more devices go wireless. Meanwhile, studies indicate that the assigned spectrum is not fully utilised. Cognitive radio (CR) technology is envisioned to be a promising solution to address the imbalance between spectrum scarcity and spectrum underutilisation. It improves the spectrum utilisation by reusing the unused or underutilised spe...

The competitive price game model is used to analyze the spectrum sharing in the cognitive radio networks. This paper focuses on the improved spectrum sharing problem with constraints of available spectrum resource from primary users. The constrained spectrum sharing model based on competitive price game is established. In order to achieve the spectrum sharing strategy that satisfies the constra...

As a key in cognitive radio networks (CRNs), dynamic spectrum access needs to be carefully designed to minimize the interference and delay to the primary (licensed) users. One of the main challenges in dynamic spectrum access is to determine when the secondary (unlicensed) users can use the spectrum. In particular, when the secondary user is using the spectrum, if the primary user becomes activ...

Cognitive radio (CR) can improve spectrum utilization by allowing the secondary users to temporarily access the primary users’ unutilized licensed spectrum. In order to guarantee quality of service (QoS) of the secondary users, spectrum handoff mechanism must be implemented in CR networks. Spectrum handoff procedures aim to help the secondary users vacate the spectrum and search the target chan...