IEICE Transactions on Electronics
Online ISSN : 1745-1353
Print ISSN : 0916-8524
Volume E104.C, Issue 5
Displaying 1-2 of 2 articles from this issue
Regular Section
  • Tati ERLINA, Renyuan ZHANG, Yasuhiko NAKASHIMA
    Article type: PAPER
    Subject area: Integrated Electronics
    2021 Volume E104.C Issue 5 Pages 153-163
    Published: May 01, 2021
    Released on J-STAGE: May 01, 2021
    Advance online publication: October 29, 2020

    An efficient approximate computing circuit is developed for polynomial functions through the hybrid of analog and stochastic domains. Different from the ordinary time-based stochastic computing (TBSC), the proposed circuit exploits not only the duty cycle of pulses but also the pulse strength of the analog current to carry information for multiplications. The accumulation of many multiplications is performed by merely collecting the stochastic-current. As the calculation depth increases, the growth of latency (while summations), signal power weakening, and disparity of output signals (while multiplications) are substantially avoidable in contrast to that in the conventional TBSC. Furthermore, the calculation range spreads to bipolar infinite without scaling, theoretically. The proposed multi-domain stochastic computing (MDSC) is designed and simulated in a 0.18 µm CMOS technology by employing a set of current mirrors and an improved scheme of the TBSC circuit based on the Neuron-MOS mechanism. For proof-of-concept, the multiply and accumulate calculations (MACs) are implemented, achieving an average accuracy of 95.3%. More importantly, the transistor counting, power consumption, and latency decrease to 6.1%, 55.4%, and 4.2% of the state-of-art TBSC circuit, respectively. The robustness against temperature and process variations is also investigated and presented in detail.

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  • Haisong JIANG, Mahmoud NASEF, Kiichi HAMAMOTO
    Article type: BRIEF PAPER
    Subject area: Optoelectronics
    2021 Volume E104.C Issue 5 Pages 164-167
    Published: May 01, 2021
    Released on J-STAGE: May 01, 2021
    Advance online publication: October 19, 2020

    This paper reports a single dimensional mode based multiplexer / de-multiplexer using the slab waveguide to realize high modes multiplexing and high integration in the non-MIMO (multi-in multi-out) multimode transmission system. A sufficient mode crosstalk of -20 dB was obtained by selecting suitable parameters of the spacing between the connecting positions of each arrayed waveguide Di, the radius slab waveguide R0 and lateral V-parameter.

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