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Guest Editorial

Author(s): Khan Mohammad Iftekharuddin | Mohammed Nazrul Islam | Mohammad Ataul Karim | Mohammad Abdus Salam

Journal: Journal of Communications
ISSN 1796-2021

Volume: 6;
Issue: 7;
Start page: 509;
Date: 2011;
Original page

Keywords: Special Issue | Wireless Communications and Networks

Wireless communication has been growing significantly in recent years with the development of communications systems, network architecture and sensors. Wireless systems will play important role in future internet and information systems. . Intense research in wireless systems includes developments in many application areas such as medical, agriculture, and military. This special issue on advances in wireless systems presents research trends and recent developments in the areas of multi-antenna sensing system, radio power optimization, reliable routing protocols, digital filter design, and mobile ad hoc networks.The special issue invited papers from around the world which prompted a significant number of submissions. In addition, a selected number of authors were invited from the IEEE International Conference on Computer and Information Technology held on December 23-25, 2010 in Dhaka, Bangladesh. We received a total of thirteen submissions which went through rigorous review process by the experts in the field. Seven papers are finally selected for publication to appear in the special issue of the journal. The authors represent academic and/or research institutions from Bangladesh, China, India, Thailand, and United Kingdom.The first paper deals with the primary user detection in cognitive radio systems. Alghamdi and Ahmed developed an optimum linear combiner multi-antenna based spectrum sensing technique using the multitaper spectrum estimation method. They showed through analyses and simulation that the proposed optimal technique requires a signal-to-noise ratio (SNR) of the order of -12 dB to achieve a probability of detection of 99.99% at a false alarm rate of 1% with additive white Gaussian noise.Han, Wang, Liu and Zhu investigate the power allocation in coordinated multi-point transmission system with remote radio units power constraints. They developed a modified water-filling power allocation technique in order to obtain the optimum downlink sum capacity with a minimum complexity. Simulation results made it obvious that the proposed method can achieve the near-optimal sum data rate utilizing relatively more transmit power.An efficient cluster head selection method is proposed in the third paper, which is based on sensor nodes’ energy per unit cost. Debroy, Sadi, and Imran showed through experimentation that adoption of certain selection criterion in the proposed method can increase the system lifetime and maximize data communication significantly as compared to similar approaches in the literature.The fourth paper presents a methodology to improve the performance of orthogonal frequency division multiple access system by employing adaptive resource allocation based on channel state information (CSI). Sivridis, Wang, and Choi minimize the effect of errors from imperfect CSI in fast fading environment and hence optimize the overhead load and uplink resources used for feedback purpose. Effectiveness of the proposed scheme is demonstrated through simulation in providing a higher overall fairness and system throughput.Channa and Ahmed propose an efficient routing scheme for post-disaster ad hoc communication networks based on the shortest possible routes with all reliable nodes. The technique detects packet forwarding misbehavior caused by network fault or congestion in an active route and reroutes packets through other reliable route. Theoretical analyses and simulation results verify the significant performance improvement in terms of packet delivery ratio and delay in the presence of network fault with a reasonable increase in routing overhead.The impact of weighting factor and crossover probability on the design of low pass finite-duration impulse response digital filter as well as on the convergence behavior of the differential evolution (DE) technique is investigated by Chattopadhyay, Sanyal and Chandra in the fifth paper. The DE-optimized filter is then incorporated in a quadrature phase shift keying (QPSK) modulated system for pulse shaping purpose. Performance of the QPSK system is quantified in terms of bit error rate in order to obtain the optimized control parameters for the filter design.The final paper proposes an adaptive receiver power routing protocol for mobile ad hoc wireless network. Bello, Bakalis, Rapajic, Anang and Eneh investigate the impact of environment and signal path loss on the quality of service and throughput performance. Analytical and simulation results show that the proposed protocol increases the throughput by 62% as compared to conventional dynamic source routing protocol. The average received power for individual nodes is claimed to 1×1010 watt compared to 5×102 watt in conventional model.The guest editors would like to express their sincere gratitude to the reviewers, who have finished their reviews in the shortest possible time and dedicated their precious time to ensure the quality of this special issue. Finally, the guest editors would extend their sincere appreciation to the Associate Editor-in-Chief, Dr. Haohong Wang for providing them with this opportunity and facilitating preparation of an excellent journal special issue. 
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