IEICE Electronics Express
Online ISSN : 1349-2543
ISSN-L : 1349-2543
Volume 7 , Issue 18
Showing 1-14 articles out of 14 articles from the selected issue
LETTER
  • Tiesheng Wang, Pengfei Shi
    2010 Volume 7 Issue 18 Pages 1329-1334
    Published: 2010
    Released: September 25, 2010
    JOURNALS FREE ACCESS
    We present a new framework for recognizing dynamic textures modeled by linear dynamic systems (LDS). The new framework improves previous methods by considering between-class subspace differences. Specifically, common part among different class subspaces is removed by projecting model subspaces onto a constraint subspace before recognition. This operation increases the separability among different classes of dynamic textures. The effectiveness of the new framework is shown by experimental results.
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  • Siti Rohani S. Raihan, Nasrudin Abd. Rahim
    2010 Volume 7 Issue 18 Pages 1335-1341
    Published: 2010
    Released: September 25, 2010
    JOURNALS FREE ACCESS
    This paper presents the design and implementation of synchronous pulse-width modulation (PWM) for a three-phase three-switch Single Ended Primary Inductance Converter (SEPIC). The PWM switching patterns are generated from an Altera Cyclone II field programmable gate array (FPGA) device. Two types of carrier waveforms are used with two 60°sine waveforms, taking less space in the FPGA, providing more space for control circuits. Comparative study of two PWM methods is also shown. Verification of simulation results are based on hardware-in-the-loop technique, to show the effectiveness of digital-based PWM control.
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  • Jahangir Dadkhah Chimeh
    2010 Volume 7 Issue 18 Pages 1342-1348
    Published: 2010
    Released: September 25, 2010
    JOURNALS FREE ACCESS
    User Equipment (UE) uses data and control channels to communicate with the base station. It is necessary always to exchange control information before data exchange, in other words control information is used to establish data channels. Data channels vary depending on the UMTS releases. There is a DCH channel in R99 which is permanently assigned to the user. In the next releases of UMTS DSCH, HS-DSCH and E-DCH channels are introduced in the downlink and uplink respectively for conveying bursty data. These channels are only assigned to the user during the data burst transmission. These channels are suitable for UE power conservation. Besides, since the UE battery power is limited we need new algorithms and methods for power conservation. The customary power consumption methods in 3GPP are in layer1. In this paper using a hierarchical Internet traffic in layer 2 we try to save UE battery power. In the customary methods channel is assigned during the burst transmission while in the offered method channel is assigned only during the packet transmission time in the burst period.
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  • Hyung-Min Park, Hyun-Bae Jin, Jin-Ku Kang
    2010 Volume 7 Issue 18 Pages 1349-1353
    Published: 2010
    Released: September 25, 2010
    JOURNALS FREE ACCESS
    This letter describes a spread spectrum clock generator (SSCG) circuit with the Hershey-Kiss modulation profile using two stacked sigma-delta modulators. The proposed Hershey-Kiss profile modulator generates various slopes to achieve non-linear modulation profile. Since the modulators are implemented by digital blocks, it can be modified for other applications. Simulation results show that peak power reduction level of 10.2dBm with 5000ppm down spreading at the 340MHz operation using 0.13m CMOS.
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  • Masaya Ohta, Atsuo Iwase, Katsumi Yamashita
    2010 Volume 7 Issue 18 Pages 1354-1358
    Published: 2010
    Released: September 25, 2010
    JOURNALS FREE ACCESS
    N-continuous OFDM is a modulation technique that has a lower sidelobe than the original OFDM as a result of the continuous connection with its higher-order derivatives between the OFDM symbols. However, N-continuous OFDM has a high symbol error rate. In the present paper, we improve N-continuous OFDM without increasing the symbol error rate by using a selected mapping technique.
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  • Jun Itoh, Nguyen Tuan Hung, Hisashi Morishita
    2010 Volume 7 Issue 18 Pages 1359-1363
    Published: 2010
    Released: September 25, 2010
    JOURNALS FREE ACCESS
    This letter presents a mutual coupling reduction method between two J-shaped folded monopole antennas (JFMA), which cover Wireless Local Area Network (WLAN), especially for IEEE 802.11b/g band on handset. IEEE 802.11b/g is used to 2.4GHz (2400-2484MHz) band. We proposed an effective method to reduce mutual coupling by using a bridge line that links two antennas. As the analytical results, by linking the shorting strips of two JFMA elements with a bridge line, we obtained a sufficiently reduced mutual coupling and improved total antenna efficiency.
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  • Shaochong Lei, Zhen Wang, Zeye Liu, Feng Liang
    2010 Volume 7 Issue 18 Pages 1364-1369
    Published: 2010
    Released: September 25, 2010
    JOURNALS FREE ACCESS
    This paper proposes a unified solution to reduce test power and test volume for test-per-scan schemes. With the self-testing using MISR and Parallel SRSG (STUMPS) architecture and the developed reconfigurable Johnson counter, the proposed test pattern generator (TPG) applies two transition sequences to all scan chains, and the primary inputs of the circuit under test (CUT) keep unchanged at most times. Therefore, the switching activities both in the combinational block and in scan chains can be reduced simultaneously. If the generated test vectors that do not contribute to fault coverage are filtered out, the remaining deterministic patterns show the favorable features of high compressible and low-test power. Simulation results on ISCAS'89 benchmarks demonstrate that the proposed TPG imposes negligible impact on test length and power overhead of the CUT.
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  • Seong Jae Jeong, Keum Cheol Hwang
    2010 Volume 7 Issue 18 Pages 1370-1375
    Published: 2010
    Released: September 25, 2010
    JOURNALS FREE ACCESS
    This research presents the design of a novel pentaband planar antenna for wireless USB dongle applications. The main radiator is comprised of a circular hook-shaped patch and a monopole stub to achieve dual-wideband operation. This novel pentaband antenna measures only 10 × 49.5 × 0.8 mm3. The measured 10dB return loss bandwidths of the fabricated antenna are 26.2% (2.29-2.98GHz) and 21.5% (5.12-6.35GHz), thereby supporting WiBro, Bluetooth, WLAN, WiMAX, and S-DMB (Satellite Digital Multimedia Broadcast) services. The gain and radiation efficiency of the antenna are also discussed.
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  • Mohammad Sadegh Mehrjoo, Mohammad Yavari
    2010 Volume 7 Issue 18 Pages 1376-1381
    Published: 2010
    Released: September 25, 2010
    JOURNALS FREE ACCESS
    A noise reduction input matching technique for broadband low noise amplifiers (LNAs) is presented. The proposed LNA employs a positive active feedback network besides of the conventional common-gate (CG) amplifier to achieve both wideband input signal matching and low noise figure (NF), simultaneously. Compared to the conventional broadband noise cancellation techniques, the presented approach achieves the same NF with much less power consumption and high linearity. Circuit level analysis and simulation results are provided to verify the usefulness of the proposed LNA technique. In contrast to the traditional noise cancellation circuit, the proposed LNA does not degrade the linearity and its IIP3 is similar to the simple common-gate LNA. The proposed technique is applied to an LNA operating in 2∼6.5GHz bandwidth.
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  • Shuguo Li, Fuqiang Cao
    2010 Volume 7 Issue 18 Pages 1382-1387
    Published: 2010
    Released: September 25, 2010
    JOURNALS FREE ACCESS
    A double-scroll chaotic oscillator based true random number generator (TRNG) is designed and fabricated in CMOS 0.18µm process. In order to realize a TRNG suitable for CMOS process, an op-amp based chaotic oscillator is chosen and transistor-level op-amps are designed. Then, a symmetrically dividing method is proposed to exploit the statistics of chaotic signals generated by the oscillator and improve the throughput of random bits. The TRNG core occupies 0.026mm2 and dissipates 1mW. Measurements show that the generated binary bits can pass the SP800-22 test suites and FIPS140-1 standard with a throughput of 20Mbps.
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  • A. H. M. Almawgani, M. F. M. Salleh
    2010 Volume 7 Issue 18 Pages 1388-1395
    Published: 2010
    Released: September 25, 2010
    JOURNALS FREE ACCESS
    This letter presents the outage probability of the Reed Solomon (RS) coded cooperation scheme. In this scheme, the codeword of the Users are partitioned into two frames and transmitted through two independent fading channels. The first frame is transmitted directly to the base station. The second frame is transmitted via a partner to the base station. The derived outage expressions confirm that full diversity is achieved by the RS coded cooperation scheme. The analytical outage probability comparisons under various inter-user and uplink channel conditions shed light on the relative virtues of the RS coded cooperation scheme as compared to the RCPC coded cooperation scheme with around 1.5 to 2.5dB gains.
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  • Hyuntae Cho, Yunju Baek
    2010 Volume 7 Issue 18 Pages 1396-1402
    Published: 2010
    Released: September 25, 2010
    JOURNALS FREE ACCESS
    RFID (Radio Frequency Identification) is an automatic identification technology using radio waves. RFID readers are high-technology automatic identification devices based on wireless networks and enable noncontact identification; however, they cannot be applied beyond their radio communication range. Considering this, the present paper proposes multihop deployment of active RFID readers in order to extend a reader's radio coverage. Further, when a multitude of RFID readers are deployed in an RFID field, RFID tags are easily collected multiple times. Considering this situation, in this paper, we also propose reader collision avoidance for multihop deployment of active RFID readers. The proposed method not only avoids multiple reads from a tag but also extends the tag's lifetime. For experimental tests and performance evaluation, this study implements a multi-hop active RFID reader, which complies with the ISO/IEC 18000-7 standard.
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  • Nasrudin Abd. Rahim, Muhamad Mansor
    2010 Volume 7 Issue 18 Pages 1403-1408
    Published: 2010
    Released: September 25, 2010
    JOURNALS FREE ACCESS
    This paper implements two main works. First, a new voltage-sag detection technique based on phase-angle analysis is proposed. It is simple to implement and able to detect and compensate sag the moment it occurs. Second, a new topology of voltage sag compensator is introduced. The proposed topology is able to reduce stress effect due to current flows into the switches and avoid non-stop operation during sag events. This proposed work had been verified and investigated by developing a laboratory prototype where a TMS320F2812 DSP is used as the main controller.
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  • Jing Tian, Li Chen, Lihong Ma
    2010 Volume 7 Issue 18 Pages 1409-1415
    Published: 2010
    Released: September 25, 2010
    JOURNALS FREE ACCESS
    The challenge of conventional parametric model-based wavelet image denoising approaches is that the efficiency of these methods greatly depends on the accuracy of the prior distribution used for modeling the wavelet coefficients. To tackle the above challenge, a non-parametric statistical model is proposed in this paper to formulate the marginal distribution of wavelet coefficients. The proposed non-parametric model differs from conventional parametric models in that the proposed model is automatically adapted to the observed image data, rather than imposing an assumption about the distribution of the data. Furthermore, the proposed non-parametric model is incorporated into a Bayesian inference framework to derive a maximum a posterior (MAP) estimation-based image denoising approach. Experiments are conducted to not only demonstrate that the proposed non-parametric statistical model is more suitable than conventional models to formulate the marginal distribution of wavelet coefficients, but also show that the proposed image denoising approach outperforms the conventional approaches.
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