• Title/Summary/Keyword: Dual channel

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Effect of Channel and Gate Structures on Electrical Characteristics of Oxide Thin-Film Transistors (Channel과 gate 구조에 따른 산화물 박막트랜지스터의 전기적 특성 연구)

  • Kong, Heesung;Cho, Kyoungah;Kim, Jaybum;Lim, Junhyung;Kim, Sangsig
    • Journal of IKEEE
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    • v.26 no.3
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    • pp.500-505
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    • 2022
  • In this study, we designed oxide thin-film transistors (TFTs) with dual gate and tri layered split channels, and investigated the structural effect of the TFTs on the electrical characteristics. The dual gates played a key role in increasing the driving current, and the channel structure of tri layers and split form contributed to the increase in the carrier mobility. The tri layered channels consisting of the a-ITGZO and two ITO layers inserted between the gate dielectric and a-ITGZO led to the increase in the on-current by using ITO layers with high conductivity, and the split channels lowered series resistance of the channels. Compared with the mobility (15 cm2/V·s) of the single gate a-ITGZO TFT, the mobility (134 cm2/V·s) of the dual gate tri-layer split channel TFT was remarkably enhanced by the structural effect.

Statistical Model-Based Voice Activity Detection Using Spatial Cues for Dual-Channel Noisy Speech Recognition (이중채널 잡음음성인식을 위한 공간정보를 이용한 통계모델 기반 음성구간 검출)

  • Shin, Min-Hwa;Park, Ji-Hun;Kim, Hong-Kook;Lee, Yeon-Woo;Lee, Seong-Ro
    • Phonetics and Speech Sciences
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    • v.2 no.3
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    • pp.141-148
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    • 2010
  • In this paper, voice activity detection (VAD) for dual-channel noisy speech recognition is proposed in which spatial cues are employed. In the proposed method, a probability model for speech presence/absence is constructed using spatial cues obtained from dual-channel input signal, and a speech activity interval is detected through this probability model. In particular, spatial cues are composed of interaural time differences and interaural level differences of dual-channel speech signals, and the probability model for speech presence/absence is based on a Gaussian kernel density. In order to evaluate the performance of the proposed VAD method, speech recognition is performed for speech segments that only include speech intervals detected by the proposed VAD method. The performance of the proposed method is compared with those of several methods such as an SNR-based method, a direction of arrival (DOA) based method, and a phase vector based method. It is shown from the speech recognition experiments that the proposed method outperforms conventional methods by providing relative word error rates reductions of 11.68%, 41.92%, and 10.15% compared with SNR-based, DOA-based, and phase vector based method, respectively.

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Study of Characteristics of Dual Channel Trench IGBT (Dual Channel을 가진 Trench Insulated Gate Biploar Transistor(IGBT)특성 연구)

  • Moon, Jin-Woo;Chung, Sang-Koo
    • Proceedings of the KIEE Conference
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    • 2001.07c
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    • pp.1469-1471
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    • 2001
  • A Dual Channel Trench IGBT (Insulated Gate Bipolar Transistor) is proposed to improve the latch-up characteristics. Simulation results by MEDICI have shown that the latching current density of proposed device was found to be 2850 A/$cm^2$ while that of conventional device was 1610 A/$cm^2$. The latching current desity of the proposed strucutre was 77.02% higher than that of conventional structre.

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Application of the Beam Propagation Method to the analysis of Dual-channel directional couplers (Dual-channel directional couplers 동작특성 해석을 위한 BPM의 적용)

  • Kang, Kyung-Woo;Kang, Hyung-Boo
    • Proceedings of the KIEE Conference
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    • 1993.07b
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    • pp.660-662
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    • 1993
  • We have numerically analyzed by using the Beam Propagation Method the Dual-channel directional couplers, which peforms a number of useful fuctions in thin-films devices, including power division, modulation, switching, frequency selection, and polarization selection. We also use the effective index method to reduce one dimension.

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Dual-Channel MAC Protocol Using Directional Antennas in Location Aware Ad hoc Networks (위치정보 기반의 Ad hoc 네트워크에서 방향성 안테나를 이용한 Dual-Channel MAC 프로토콜)

  • Han, Do-Hyung;Kang, Chang-Nam;Jwa, Jeong-Woo
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.7-10
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    • 2005
  • Ad hoc MAC protocols using directional antennas can be used to improve the network capacity. Directional antennas have a Deafness problem and decrease throughput of the network caused by increasing backoff duration. Dual channel protocols have been proposed to mitigate the Deafness and hidden node problems. In this paper, we propose a dual channel MAC protocol using a directional antenna to mitigate the Deafness problem and increase the network capacity. The performance of the proposed Ad hoc MAC protocol is confirmed by computer simulations using Qualnet ver. 3.8 simulator.

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Tone Dual-Channel MAC Protocol with Directional Antennas for Mobile Ad Hoc Networks

  • Jwa, Jeong-Woo
    • ETRI Journal
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    • v.34 no.1
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    • pp.98-101
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    • 2012
  • The directional medium access control (MAC) protocol improves the throughput of mobile ad hoc networks but has a deafness problem and requires location information for neighboring nodes. In the dual-channel directional MAC protocol [12], the use of omnidirectional packets does not require the exact location of destination node. In this letter, we propose a tone dual-channel MAC protocol with directional antennas to improve the throughput of mobile ad hoc networks. In the proposed MAC protocol, we use a directional CTS and an out-of-band directional DATA tone with a new blocking algorithm to improve the spatial reuse. We confirm the throughput performance of the proposed MAC protocol by computer simulations using the Qualnet simulator.

A Tone Dual-Channel DMAC Protocol in Location Aware Ad Hoc Networks (위치 정보 기반의 Ad hoc 네트워크에서 Tone 을 사용한 Dual-Channel DMAC 프로토콜)

  • Lee, Eun-Ju;Han, Do-Hyung;Jwa, Jeong-Woo
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.57-58
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    • 2006
  • Ad hoc MAC protocols using directional antennas can be used to improve the network capacity by improving spatial reuse. But, the directional MAC protocols have the problem of deafness and have a poor throughput performance. The dual-channel DMAC protocol has been proposed to mitigate deafness and improve spatial reuse. In this paper, we propose a dual-channel DMAC protocol using the omnidirectional antenna for an out-of-band tone and directional antennas for control/data channels. In the proposed MAC protocol, an omnidirectional out-of-band tone mitigates deafness and directional antennas used in control/data channels improve spatial reuse and reduce interference packets. The throughput performance of the proposed MAC protocol is confirmed by computer simulations using Qualnet ver. 3.8 simulator.

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A Novel Broadband Channel Estimation Technique Based on Dual-Module QGAN

  • Li Ting;Zhang Jinbiao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.18 no.5
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    • pp.1369-1389
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    • 2024
  • In the era of 6G, the rapid increase in communication data volume poses higher demands on traditional channel estimation techniques and those based on deep learning, especially when processing large-scale data as their computational load and real-time performance often fail to meet practical requirements. To overcome this bottleneck, this paper introduces quantum computing techniques, exploring for the first time the application of Quantum Generative Adversarial Networks (QGAN) to broadband channel estimation challenges. Although generative adversarial technology has been applied to channel estimation, obtaining instantaneous channel information remains a significant challenge. To address the issue of instantaneous channel estimation, this paper proposes an innovative QGAN with a dual-module design in the generator. The adversarial loss function and the Mean Squared Error (MSE) loss function are separately applied for the parameter updates of these two modules, facilitating the learning of statistical channel information and the generation of instantaneous channel details. Experimental results demonstrate the efficiency and accuracy of the proposed dual-module QGAN technique in channel estimation on the Pennylane quantum computing simulation platform. This research opens a new direction for physical layer techniques in wireless communication and offers expanded possibilities for the future development of wireless communication technologies.

Performance of SDR-Based Digital-IF Channelization for Dual-Band DS-CDMA System in Wideband Multipath Channel

  • jeon, Jun-Soo
    • Journal of information and communication convergence engineering
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    • v.2 no.4
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    • pp.205-208
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    • 2004
  • In this paper, we analyzed the performance of SDR-based dual-band CDMA system in wideband multipath channel employing RAKE receiver with MRC diversity. For the simulation of SDR-based dual-band CDMA system, we used digital IF techniques, polyphase analysis filter bank as channelizer. Also, Remez exchange algorithm is employed in the realization of the digital filter in the polyphase analysis filter bank. For performance analysis of dual-band CDMA system, we consider power loss of IF signal after passing through channel and the filter. Also, the performance for different sampling rates is analyzed.

Tone Dual-Channel Directional MAC Protocol for Mobile Ad-Hoc Networks

  • Jwa, Jeong-Woo
    • International Journal of Contents
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    • v.7 no.2
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    • pp.6-10
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    • 2011
  • The directional MAC (DMAC) protocol improves the spatial reuse, but directional packets on the control channel cause the deafness problem. In this paper, we propose a tone dual-channel DMAC protocol for mobile ad-hoc networks. In the proposed MAC protocol, the use of omnidirectional transmissions using an omnidirectional out-of-band tone solves the deafness problem and decrease packet collisions on the control channel. The use of an omnidirectional out-of-band tone also mitigates the hidden terminal problem. We use the negative CTS (NCTS) mechanism to solve the exposed terminal problem. The throughput performance of the proposed MAC protocol is confirmed by simulations using the Qualnet simulator.