Straight microstrip lines alternately loaded with ground slots and open-end stubs are analyzed. Fabricated samples containing slots and stubs with various length combinations demonstrate constant slow-wave factors of 1.7 to 3.0 with negligible amounts of radiation loss and larger characteristic impedance tuning range. A slow-wave band-rejection filter at 1.8GHz is built for performance comparison with a regular microstrip-line filter.

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In this letter, we propose a novel approximate method for throughput calculation of crossbar switch with buffers only in crosspoints, in the case of uniform traffic. It is an iterative method based on the balance equations that describe crosspoint buffer state. Due to some approximations, we derive very simple formulas suitable for matrix calculation. This method gives results very close to the results obtained by numerous simulations, especially for larger switch and long buffers.

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A novel square patch antenna with reconfigurable circular polarization (CP) is presented in this letter. A circular slot with perturbation is placed beneath the patch. The circular slot that has an inner perturbation yields right-handed CP, but with an outer perturbation slot yields left-handed CP. Experiments show an antenna gain of 2.8dBic and a 3-dB axial ratio bandwidth of 30MHz which well match the corresponding simulation results.

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This paper investigates the relationship between averaged SAR (Specific Absorption Rate) over 10g mass and temperature elevation in Japanese numerical anatomical models when devices are mounted on the body. Simplifying the radiation source as a half-wavelength dipole, the generated electrical field and SAR are calculated using the FDTD (Finite-Difference Time-Domain) method. Then the bio-heat equation is solved to obtain the temperature elevation due to the SAR derived using the FDTD method as heat source. Frequencies used in the study are 900MHz and 1950 MHz, which are used for mobile phones. In addition, 3500MHz is considered because this frequency is reserved for IMT-Advanced (International Mobile Telecommunication-Advanced System). Computational results obtained herein show that the 10g-average SAR and the temperature elevation are not proportional to frequency. In addition, it is clear that those at 3500MHz are lower than that at 1950MHz even though the frequency is higher. It is the point to be stressed here is that good correlation between the 10 g-average SAR and the temperature elevation is observed even for the body-worn device.

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We deal with a path selection problem for heterogeneous wireless networks integrated with Frequency Agile Access Points. Our goal is to find the minimum achievable amount of radio resources required to set up a transmission path. We propose to formulate the path selection approach as a minimum cost flow problem.

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A low peak-to-average-power-ratio (PAPR) transceiver with a time-frequency cyclic shift orthogonal keying (TF-CSOK) technique is proposed for the uplink multi-carrier CDMA (MC-CDMA) system over multiple access interference (MAI) and multipath interference (MPI) channels. The low complexity structure of the TF-CSOK MC-CDMA system is designed to involve the FCSOK and TCSOK techniques to combat MPI and MAI effects, respectively. In particular, at the besestation, the multiuser detector employs the maximum likelihood (ML) rule and the TFSOK despreading and demapping techniques to acquire the M-ary modulation gain and diversity gain. Simulation results show that the multuser receiver has the robustness against strong MAI. Moreover, it outperforms the conventional single-carrier frequency division multiple access (SC-FDMA) system and the conventional MC-CDMA system under MAI and MPI environments.

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Base station (BS) cooperation is a promising technique to suppress co-channel interference for cellular networks. However, practical limitations constrain the scale of cooperation, thus the network is divided into small disjoint BS cooperation groups, namely clusters. A decentralized scheme for BS cluster formation is proposed based on efficient BS negotiations, of which the feedback overhead per user is nearly irrelevant to the network size, and the number of iteration rounds scales very slowly with the network size. Simulations show that our decentralized scheme provides significant sum-rate gain over static clustering and performs almost the same as the existing centralized approach. The proposed scheme is well suited for large-scale cellular networks due to its low overhead and complexity.

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The patching technique has been used for reducing initial waiting time in VOD services. Traditionally the technique has been applied to fixed segment NVOD scheduling. However, variable segment NVOD scheduling is known to have a better server bandwidth and less initial waiting time. In this paper, we propose a new scheduling algorithm for a true VOD service by incorporating the patching technique into variable segment NVOD scheduling. Our algorithm provides jitter-free playback while minimizing the use of the patching bandwidth. We present the proof of the correctness of our algorithm.

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