Hiroyo Ogawa

National Institute of Information and Communications Technology, Edo, Tōkyō, Japan

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Publications (24)13.8 Total impact


  • No preview · Conference Paper · Sep 2014
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    ABSTRACT: The Radio on Fiber (RoF) technologies are unique transmission means of radio analog signals through optical fiber cables. These technologies are currently discussed at international standard organizations such as ITU-T, IEC, APT and IEEE802. This invited paper summarizes RoF standardization activities at those standard organizations.
    No preview · Conference Paper · Dec 2013
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    ABSTRACT: A multigigabit relay transceiver system based on analog radio-over-fiber technology is proposed and experimentally evaluated for broadband radio-signal transmission in the millimeter-wave band, particularly at 60 GHz. The combination of a high-speed optical modulator and a photodiode provides signal delivery over an optical fiber. The observed dynamic range and resultant error vector magnitude of a 16-ary quadrature amplitude modulation signal compliant with the IEEE 802.11ad Standard, designated for a wireless local access network at 60 GHz, can be within the limit set by the standard.
    Full-text · Article · Dec 2013 · IEEE Photonics Journal
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    ABSTRACT: This paper describes the outline of recent standardization activities for Radio on Fiber (RoF) transmitter by IEC TC103/WG5. RoF transmitter consists of optical fibers, electrical to optical (E/O) converter, and optical to electrical (O/E) converter. IEC TC103/WG5 is working on standardization on measurement method of E/O and O/E devices, and technical specification of RoF transmitter. This paper overviews those standardization activities which are being developed by TC103/WG5 as well as the National Committee of WG5.
    No preview · Article · Feb 2013 · IEICE Transactions on Electronics
  • Chang-Soon Choi · Yozo Shoji · Hiroyo Ogawa
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    ABSTRACT: This paper presents the developed orthogonal frequency division multiplexing (OFDM) baseband processor employing adaptive modulations to grouped subcarriers, and its demonstration in millimeter-wave wireless indoor links. Channel measurements and characterizations are performed in line-of-sight (LOS) office environments where the developed OFDM system is supposed to be used. The OFDM baseband processor utilizes 192 data subcarriers among 256 FFT numbers. To minimize bit-error-rate (BER) performance in frequency selective channels of millimeter-wave wireless indoor links, these 192 data subcarriers are grouped into 24 subcarrier groups and independently modulated according to channel characteristics in each subcarrier group. We demonstrate it incorporating with the developed 70 GHz selfheterodyne transceiver. BER measurements and maximum TCP throughput test are performed in practical millimeterwave indoor environments. The results verify the advantages of the proposed adaptive modulation in OFDM and show better BER performance as well as higher throughput performance than a typical OFDM system1.
    No preview · Article · Nov 2011 · IEEE Transactions on Consumer Electronics
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    ABSTRACT: A modified Saleh-Valenzuela (SV) model, which is useful in designing a millimeter-wave WPAN (mmW WPAN) system for line-of-sight (LoS) desktop environments, is proposed. It is demonstrated that a well-known two-path model component is dominantly observed in a typical LoS desktop channel along with the components of the other non-line-of-sight (NLoS) paths. Then, the deterministic two-path model is extended to a statistical two-path model by introducing random variables for the antenna position and merging with the conventional SV-model which is suitable to express NLoS path components. The proposed channel model parameters are extracted in a typical LoS desktop environment, and then the cumulative distribution of total path power gain is discussed using a simulation technique that assumes a specific antenna location scenario. It is shown that the cumulative distribution of total path power gain obtained using the proposed model is useful to estimate the outage probability of the mmW WPAN link.
    No preview · Article · Nov 2009 · IEEE Transactions on Antennas and Propagation
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    ABSTRACT: This paper presents the activities of a feasibility study for LiNbO<sub>3</sub> Mach-Zehnder modulators and systems. In addition, the structure of IEC standardization, standardization activities of IEICE Japan, and international round-robin test results are described.
    No preview · Conference Paper · Nov 2008
  • Chang-Soon Choi · Yozo Shoji · Hiroyo Ogawa
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    ABSTRACT: This paper describes new 60-GHz-band bidirectional fiber-fed wireless access systems, which provide simple antenna base-station architecture and full compatibility with dense wavelength-division multiplexing (DWDM) fiber-optic networks. For downlink millimeter-wave signal generation, the proposed scheme utilizes uplink optical transmitters as downlink optical heterodyne sources, which promises wavelength allocations of downlink and uplink signals that are fully compatible with those of DWDM networks. The frequency instability and poor phase-noise characteristics of these optically heterodyned signals do not affect transmission quality at all by using self-heterodyne wireless transmission techniques. Experimental results demonstrate that the proposed scheme provides not only strong immunity to phase-noise degradation coming from both fiber and millimeter-wave links, but also less sensitivity to fiber transmission loss than conventional remote optical heterodyne approaches. With the help of these attractive features, we successfully demonstrate both downlink and uplink orthogonal frequency-division multiplexing data transmissions in both 10-km fiber-optic and 60-Hz links.
    No preview · Article · Feb 2008 · IEEE Transactions on Microwave Theory and Techniques
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    ABSTRACT: A novel cost-effective 60-GHz multi-chip module (MCM) is proposed and demonstrated. It is based on a low-cost multilayer printed wiring board (PWB) with a novel vertical transition and a single layer waveguide transition which enables the use of low-cost substrates with high dielectric loss for millimeter wave applications. The proposed MCM technology has been successfully applied to the packaging of a 60-GHz self-heterodyne mixer, and no substantial difference in the RF performance is observed with the packaging. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2303–2305, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22719
    Full-text · Article · Sep 2007 · Microwave and Optical Technology Letters
  • Yozo Shoji · Chang-Soon Choi · Hiroyo Ogawa
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    ABSTRACT: Millimeter-wave OFDM wireless personal area network system applying adaptive modulation for grouped sub-carriers was newly developed. It is composed of 100 MHz sampling speed OFDM modems which can employ adaptive modulation for every 8 neighbored subcarriers, and 70-GHz band self-heterodyne transceivers equipped with receiver space diversity. The detailed specifications and the expected maximum throughput performance are described. The operational principle of the developed system under selective multipath channel environment is also discussed. The fundamental test results demonstrate the use of developed adaptive modulation for millimeter-wave OFDM WPAN system has the possibility to improve the throughput performance under multipath channel environment
    No preview · Article · Jan 2007
  • Yozo Shoji · Chang-Soon Choi · Hiroyo Ogawa
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    ABSTRACT: 70-GHz-band orthogonal frequency-division multiplexing (OFDM) transceivers were developed by combining self-heterodyne transmission with two-element diversity reception. The transceivers were used to study and demonstrate a millimeter-wave wireless personal network that enables cost-effective broadband data transmissions in a multipath channel environment. A 100-MHz sampling OFDM modulator/demodulator was developed for the baseband part. It has a payload data rate of 100 Mb/s using quadrature phase-shift keying (QPSK) modulation and a coding rate of 3/4 (many other modulations and coding rate are available). The bit error rate was experimentally evaluated when a pair of devices was placed on a wooden table under line-of-sight path conditions. The results showed that the combined use of the self-heterodyne technique and two-element diversity receiver successfully avoids serious signal fading at unpredictable transmission distances. The transceiver with QPSK modulation and coding rate of 1/2 for forward error correction achieves error-free data transmission over a distance of up to 3.4 m. In addition, a successful transmission in 64 quadrature amplitude modulation mode was demonstrated, although the communication range was quite short
    No preview · Article · Nov 2006 · IEEE Transactions on Microwave Theory and Techniques
  • Kiyoshi Hamaguchi · Hiroyo Ogawa
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    ABSTRACT: In this paper we describe overview of the test-bed using gigabit millimeter-wave broadband wireless access systems using 32/18/37 GHz bands. Then, specification and performance of a portable customer-premise equipment employing 4-states combination of adaptive modulation and forward error correction at 32 GHz as a part of the test-bed is introduced. Empirically derived formula of the number of rain fade events per year is also derived to assist designing for unavailability at millimeter wave links.
    No preview · Conference Paper · Jan 2006
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    Yozo SHOJI · Yoshihiro HASHIMOTO · Hiroyo OGAWA
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    ABSTRACT: A fiber-optic broadband signal distribution link based on a millimeter-wave self-heterodyne transmission/optical remote heterodyne detection technique was developed. To avoid having to use expensive optical and millimeter-wave devices to construct a frequency-stable fiber-optic millimeter-signal transmission system, a millimeter-wave self-heterodyne transmission technique was used, in which transmitted signals were generated by an optical remote heterodyne detection scheme. Theoretical discussion and experiments demonstrated that it is possible to construct an inexpensive millimeter-wave signal distribution link without the complexity or difficulties of a conventional link structure because applying the principle of the millimeter-wave self-heterodyne transmission technique enables the use of an unstable millimeter-wave carrier generated by heterodyning of two independently operating lasers. It was experimentally demonstrated that the proposed fiber-optic millimeter-wave link could successfully achieve bit-error-free transmission of a 156-Mb/s QPSK-formatted signal over a 10-km fiber link and a 5-m pseudo-air link.
    Preview · Article · Jul 2005 · IEICE Transactions on Electronics
  • Osamu Anegawa · Kiyoshi Hamaguchi · Hiroyo Ogawa
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    ABSTRACT: A new automatic-threshold-control (ATC) system for the amplitude-shift-keying (ASK) transceivers without using automatic gain control (AGC) was developed. When signal-to-noise ratio (SNR) in a transmission system fluctuates, the new system optimizes the threshold by statistic processing. In this paper, the schematic block diagram, the theory of statistical processing, and the performance estimated by numerical simulations are shown. The simulations show that under ideal conditions, the system can control the threshold voltage in a broad SNR region (wider than 20 dB). Delay of response and trapping in real situation can occur, but, the problems can be avoided by waveform shaping. It is thus concluded that the new ATC system can be applied to ASK transceivers.
    No preview · Article · Mar 2005 · IEICE Transactions on Communications
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    Full-text · Article · Jan 2005
  • Yozo Shoji · Hiroyo Ogawa
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    ABSTRACT: Our proposed millimeter-wave self-heterodyne transmission technique is a simple and cost-effective solution to frequency stability problems in millimeter-wave access systems. In addition, this technique enables integration of a high-sensitivity receiver with a combining antenna diversity system that is approximately as effective as a maximal-ratio-combining antenna diversity system for all directions of signal arrival. We explain how our newly developed 70-GHz-band transceiver using the millimeter-wave self-heterodyne transmission technique with a receiver-module array can greatly improve receiver sensitivity for all directions of signal arrival i.e., without affecting the signal reception beam pattern and how this can solve the signal-fading problem in a multipath signal propagation environment. We also theoretically demonstrate that receiver sensitivity improves in proportion to the number of elements in a receiver-module array, and experimentally confirm this using an experimental 70-GHz-band monolithic microwave integrated circuit transceiver with a 4×2 receiver-module array. We show that millimeter-wave signal propagation can be modeled using a two-path model, and that serious signal fading depends on the transceiver height and transmission distance. Carrier and modulated signal transmission experiments using our developed transceiver have revealed that use of a receiver-module array greatly reduces the signal-fading problem in a multipath signal propagation environment. In the signal transmission experiment, we succeeded in transmitting an orthogonal frequency-division multiplexing signal over a 4-m transmission distance with bit-error-free performance.
    No preview · Article · Dec 2004 · IEEE Transactions on Microwave Theory and Techniques
  • Yozo Shoji · Kiyoshi Hamaguchi · Hiroyo Ogawa

    No preview · Article · Jan 2002 · The Journal of The Institute of Image Information and Television Engineers
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    ABSTRACT: The design and performance of a millimeter-wave video transmission system using 60-GHz band for indoor broadcasting-satellite (BS) signals transmission is presented. This system can transmit multiple video signals such as broadcasting signals and user-oriented signals to a television set indoors. To minimize the local oscillator's frequency offset and phase-noise effects, the system uses a self-heterodyne scheme. Based on the concept, the system is developed to meet required carrier-to-noise-power- ratio (CNR) and 3rd-order intermodulation (IM). The BS transmission was experimentally done by using the transmitter and receiver setup. The results are very promising and show the feasibility of the system.
    No preview · Article · Dec 2001 · IEICE Transactions on Electronics
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    ABSTRACT: This paper describe the broad band antennas for a wireless video home-link. 8×8 circular waveguide array antenna with stripline feed are developed. The maximum antenna gain was 22dBi and 3dB bandwidth was 6GHz (10%) at V band.
    No preview · Conference Paper · Nov 2000
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    ABSTRACT: A concept and requirements of a millimeter-wave video transmission system as a wireless home-link using 60-GHz band are described. This system can transmit broadcast television (TV) signals from TV antennas to TV set and thus can be regarded as a substitute for a feeder line. The feasibility study by investigating the system's CNR and SNR performances using MMIC-based experimental setup is also described.
    No preview · Conference Paper · Nov 2000