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[Keyword] quasi-millimeter-wave(2hit)

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  • A 4-Gbps Quasi-Millimeter-Wave Transmitter in 65 nm CMOS and a Fast Carrier and Symbol Timing Recovery Scheme

    Vishal V. KULKARNI  Hiroki ISHIKURO  Tadahiro KURODA  

     
    PAPER-Integrated Electronics

      Vol:
    E93-C No:1
      Page(s):
    120-127

    A CMOS wireless transceiver operating in the 14-18 GHz range is proposed. The receiver uses direct conversion architecture for demodulation with a fast carrier and symbol timing recovery scheme. The transmitter uses a PLL and an up-conversion mixer to generate BPSK modulated signal. A ring oscillator is used in the PLL to make faster switching for burst transmission obtaining high speed low power operation. The transceiver operation has been verified by system simulation while the transmitter test-chip was fabricated in 65 nm CMOS technology and verified with measured results. The transmitter generates a bi-phase modulated signal with a center frequency of 16 GHz at a maximum data rate of 4 Gb/s and consumes 61 mW of power. To the best knowledge of authors, this is lowest power consumption among the reported transmitters that operate over 1 Gb/s range. The transceiver is proposed for a target communication distance of 10 cm.

  • Long-Span Quasi-Millimeter-Wave-Band Fixed Wireless Access System Employing Link Adaptation by Symbol Rate

    Mitsutoshi MATSUDA  Kazuji WATANABE  Hirofumi ICHIKAWA  

     
    PAPER-Terrestrial Radio Communications

      Vol:
    E87-B No:1
      Page(s):
    117-123

    Quasi-millimeter-wave-band Fixed Wireless Access (FWA) systems have higher transmission rates than 2.4-GHz or 5-GHz systems, because the available frequency bandwidth for quasi-millimeter-wave-bands is broader than the 2.4-GHz and 5-GHz bands. However, quasi-millimeter-wave-band systems are unsuitable for long-span transmission because the attenuation caused by rain is large. We propose that the symbol rate be lowered for rainfall; i.e., when it rains, a low symbol rate is used. This means narrowing the equivalent noise bandwidth so that a margin for rain attenuation is obtained. We compared a method in which the symbol rate is either high or low with one in which the symbol rate is selectable over a range of values. We verified the beneficial effect of the two-rate method through calculations and simulations. A case study in the Tokyo metropolitan area showed that the service zone radius of this method is double that of conventional systems. Changing to a low symbol rate decreases the transmission rate, but periods of heavy rainfall comprise only about 1% of the amount of time in a year, and so the average decrease in the transmission rate is approximately zero.