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Cognitive radio (CR) is the current growing technology in wireless communication field and has increase the ability to use the frequency spectrum more properly. The main objective of cognitive radios is to sense the surrounding and use primary user's vacant spaces and allot them to the secondary users without interference each other. This paper presents the optimal solution and optimizes the Quality...
In this paper we consider the link adaptation problem per Secondary User when adopting orthogonal frequency division multiplexing (OFDM)-based cognitive radio networks. The main issue herein is to provide a high Quality of Service (QoS) to SUs, while tolerating that the mutual interference between this latter and the primary user (PU) persists within a given range. To address this constrained problem,...
Here in this paper we devised a novel meticulous progression based GA technique for QoS adequacy latitude aware routing in Cognitive Wireless Mesh Networks. The past decade research towards spectrum sensing strategies for Cognitive Wireless Mesh Networks is continuing with magnitude speed. However, the majority of the routing solutions devised in past are dealing only with the optimality of the data...
Cognitive radio allows unlicensed operation in licensed bands to meet the growing demand for radio spectrum. The intelligent device, in a spectral environment, must detect free frequencies to create a cognitive network without interfering licensed users. In this paper, we are interested in finding the optimal spectrum to be allocated to users in cognitive radio networks by ensuring quality of service...
Cognitive radio network is one of the emerging areas in the field of next generation wireless network. This network is an alternative and more suitable solution to the high demands of resources for facilitating integrated & multimedia services. Instead of fixed spectrum allocation as it is done in conventional wireless networks, the cognitive radio network is based on dynamic spectrum allocation...
The channel assignment problem is an important issue in cognitive radio networks because the conventional fixed spectrum allocation mechanism leads to significant spectrum underutilization. In this paper, the QoS-aware channel assignment is formulated as an optimization problem. The objective is to maximize the utilization of spectrum opportunities and fairness among secondary users (SUs) subject...
The rapid evolution of new wireless technologies and deployment of wireless devices in recent years is resulting in spectrum overcrowding [1]. It is observed that large amount of spectrum is under-utilized causing spectral crisis [1]. Cognitive Radio (CR) has emerged as a cutting edge technology to solve the spectrum management problem and simultaneously meet the QoS requirements of the wireless applications...
Recently cognitive radio based approaches have been introduced in inter-vehicle communication (IVC) system due to inherent advantages. Spectrum mobility is very frequent in IVC due to the mobility of vehicles and unpredictable radio frequency (RF) channel. This requires an efficient white space optimization technique to ensure spectrum management function. In this paper, a modified genetic algorithm,...
The availability of radio spectrum resource is becoming scarce with advancements in the communication applications. Most of the available spectrum has already been licensed and there would be a time when further developments in the field would be limited due to unavailability of this resource. Cognitive radio (CR) provides for the optimization of the available spectrum. The spectrum licensed is not...
In this paper, adaptive beamforming scheme which employs GA was proposed in the downlink of the cognitive radio networks to minimize maximum interference power to the primary users subject to QoS constraints of the secondary users. Performance of the proposed scheme was investigated by some numerical simulation results.
Cognitive radio(CR) is a potential technology for efficient utilization of under-utilized spectrum via spectrum sensing. CR users should move from current allocating channel to empty channel to avoid the interference to the primary user if the primary user is allocated that channel. Thus, CR system cannot support the CR user's QoS(quality of service). In this paper, we propose a dynamic frequency...
A cognitive radio (CR) network is a secondary network operating in the frequency band and geographical area of a primary network to which the spectrum is licensed. In this paper, we consider a primary broadcasting network consisting of a transmitter and a number of primary users (PUs). The secondary users (SUs) make opportunistic unlicensed spectrum access to communicate with their base station (BS)...
In this paper, we investigate the adaptive transmission in cognitive radio networks using genetic algorithms (GA), the relevant communication parameters are optimized in a dynamic wireless channel environment. Firstly, we give the variables representing the transmission parameters that can be controlled by the system, several objective functions in different layers must also be determined to define...
Under Cognitive radio (CR), the Quality of Service (QoS) suffers from many dimensions or metrics of communication quality for improving spectrum utilization. To investigate this issue, this paper develops a methodology based on the multiobjective optimization model with genetic algorithms (GAs). The influence of evolving a radio defined by a chromosome is identified. The Multiobjective Cognitive Radio...
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