International Journal of Communication Systems

Cover image for Vol. 26 Issue 2

February 2013

Volume 26, Issue 2

Pages 139–275

  1. Research Articles

    1. Top of page
    2. Research Articles
    1. Predicting group partitions in mobile ad hoc networks (pages 139–160)

      Yan Zhang, Chor Ping Low, Jim Mee Ng and Ting Wang

      Article first published online: 24 AUG 2011 | DOI: 10.1002/dac.1333

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      A group partition in group mobility may cause communication interruption in MANETs. A group partition prediction algorithm is used to predict group partitions. This paper proposes such an effective algorithm to predict group partitions in MANETs.

    2. Comparison of different antenna arrays for the BER reduction in indoor wireless communication (pages 161–176)

      Min-Hui Ho, Chien-Ching Chiu and Shu-Han Liao

      Article first published online: 1 SEP 2011 | DOI: 10.1002/dac.1334

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      In this paper, we use the ultra wideband (UWB) antenna array combining particle swarm optimizer (PSO) to minimize the bit error rate (BER) for indoor communication system. Three types of antenna arrays such as circular shape, L shape, and Y shape arrays are used in the transmitter and their corresponding BER on several paths in the indoor environment are calculated. As a result, the BER can be reduced substantially in indoor UWB communication system.

    3. Network Mobility in satellite networks: architecture and the protocol (pages 177–197)

      Abu Zafar M. Shahriar, Mohammed Atiquzzaman and William Ivancic

      Article first published online: 30 AUG 2011 | DOI: 10.1002/dac.1338

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      Network Mobility can be applied to satellite networks to ensure continuous transfer of data from satellite networks to the ground. We have shown architecture and protocol to apply network mobility to satellite networks. Results verify that network mobility can handle the mobility in satellite networks efficiently.

    4. Performance analysis of multicast routing and wavelength assignment protocol with dynamic traffic grooming in WDM networks (pages 198–211)

      N. Kaliammal and G. Gurusamy

      Article first published online: 10 OCT 2011 | DOI: 10.1002/dac.1339

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      In a WDM network, the route decision and wavelength assignment of lightpath connections are based mainly on the routing and wavelength assignment (RWA). In this paper, a multicast RWA protocol for capacity improvement in WDM networks is designed. In the wavelength assignment technique, paths from the source node to each of the destination nodes and the potential paths are divided into fragments by the junction nodes and these junction nodes have the wavelength conversion capability. By using the concept of fragmentation and grouping, the proposed scheme can be generally applied for the wavelength assignment of multicast in WDM networks. An optimized dynamic traffic grooming algorithm is also developed to address the traffic grooming problem in mesh networks in the multicast scenario for maximizing the resource utilization and minimizing the blocking probability.

    5. Efficient use of DS/CDMA signals for broadband communications over power lines (pages 212–221)

      A.K.S. Al-Bayati, O.M. Aloquili and J.I. Al Nabulsi

      Article first published online: 8 SEP 2011 | DOI: 10.1002/dac.1340

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      This paper investigates the use of DS/CDMA signals for broadband communications over power lines, using Gold codes and specially designed codes (eigen codes) and employing a zero-forcing multiuser receiver. In contrast to some earlier results on CDMA and OFDM, we show that DS/CDMA signals can be optimized to achieve an overall data throughput of approximately 80% of that achieved by OFDM systems. This shows that DS/CDMA signaling can be a good candidate for broadband power line communications.

    6. Optimization of sensing time in multichannel sequential sensing for cognitive radio (pages 222–235)

      Xian Zhang, Qihui Wu and Jinlong Wang

      Article first published online: 19 SEP 2011 | DOI: 10.1002/dac.1341

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      This paper studies the design of sensing time in multichannel sequential sensing for cognitive radio under the multichannel sensing slots and one transmission slot scheme. A suboptimal and low-complexity approach of one-slot sensing time without knowing the channel idle probability is proposed in this paper. The proposed approach solves the problem of sensing order by selecting the channel with the minimum sensing time in the next sensing slot when the channels’ SNRs are different.

    7. Two efficient and stable MMSE detection algorithms for the V-BLAST system (pages 236–249)

      T.-H. Liu

      Article first published online: 13 SEP 2011 | DOI: 10.1002/dac.1343

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      We propose two efficient and stable algorithms for the V-BLAST system. The average number of multiplications required by our proposed algorithm 1 is about (29/10)M 3, where both the numbers of transmit and receive antennas are equal to M. Our proposed algorithm 2 is completely based on Givens rotations, which is to be implemented by CORDIC based hardwares.

    8. Limits of digital unit–remote radio unit distance and cell coverage induced by time division duplex profile in mobile WiMAX systems (pages 250–258)

      Sung-Man Kim

      Article first published online: 21 OCT 2011 | DOI: 10.1002/dac.1356

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      We analyze the theoretical limits induced by the time division duplex profile of mobile WiMAX: (i) the maximum distance between the digital unit and remote radio unit; (ii) the maximum number of cascading radio units that can be connected to a digital unit; and (iii) cell coverage of the radio unit.

    9. A fault-tolerant group key agreement protocol exploiting dynamic setting (pages 259–275)

      Zi-Yao Cheng, Yun Liu, Chin-Chen Chang and Cheng Guo

      Article first published online: 21 JAN 2013 | DOI: 10.1002/dac.2506

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      We propose a novel group key agreement protocol with fault-tolerance capability and dynamic setting. Our practical method enhances the security level of system on quality. The proposed protocol is more secure and efficient for networks with collaborative group communications.