The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform

Branka Vucetic - One of the best experts on this subject based on the ideXlab platform.

Paul Hursky - One of the best experts on this subject based on the ideXlab platform.

  • Multiinput multioutput ofdm for shallow water uwa communications
    Journal of the Acoustical Society of America, 2008
    Co-Authors: Yunus Emre, Vinod Kandasamy, Tolga M Duman, Paul Hursky
    Abstract:

    We investigate performance of turbo coded multiple‐input multiple‐output (MIMO)‐OFDM systems with layered space time (LST) architectures for underwater acoustic (UWA) channels by using simulations and results from the AUVfest experiment performed in June 2007. MIMO systems have been shown to be promising in the sense that they increase the reliable transmission rates significantly without consuming additional bandwidth and power. Robustness of OFDM systems with cyclic prefix or zero padding to ISI channels are also well known; so the combination of MIMO techniques and OFDM can be regarded as a promising technology for shallow water UWA communications which is characterized by severe bandwidth limitations and long intersymbol interference (ISI) spans. The paper reviews necessary components of a MIMO‐OFDM communication system, including, time and frequency synchronization, channel estimation, and tracking of the varying channel parameters. Modifications necessary to make the system suitable for UWA channels are summarized. Results of the AUVFest 2007 experiment are very promising; for instance, 2×2 MIMO‐OFDM can reach up to 60 Kbps transmission for a bandwidth of 16 KHz with simple receiver structures for a range of 2000 m. In addition to the coherent system, differential and unitary space‐time coded MIMO‐OFDM scenarios are also considered.

  • Multiinput multioutput OFDM for shallow‐water UWA communications
    Journal of the Acoustical Society of America, 2008
    Co-Authors: Yunus Emre, Vinod Kandasamy, Tolga M Duman, Paul Hursky
    Abstract:

    We investigate performance of turbo coded multiple‐input multiple‐output (MIMO)‐OFDM systems with layered space time (LST) architectures for underwater acoustic (UWA) channels by using simulations and results from the AUVfest experiment performed in June 2007. MIMO systems have been shown to be promising in the sense that they increase the reliable transmission rates significantly without consuming additional bandwidth and power. Robustness of OFDM systems with cyclic prefix or zero padding to ISI channels are also well known; so the combination of MIMO techniques and OFDM can be regarded as a promising technology for shallow water UWA communications which is characterized by severe bandwidth limitations and long intersymbol interference (ISI) spans. The paper reviews necessary components of a MIMO‐OFDM communication system, including, time and frequency synchronization, channel estimation, and tracking of the varying channel parameters. Modifications necessary to make the system suitable for UWA channels are summarized. Results of the AUVFest 2007 experiment are very promising; for instance, 2×2 MIMO‐OFDM can reach up to 60 Kbps transmission for a bandwidth of 16 KHz with simple receiver structures for a range of 2000 m. In addition to the coherent system, differential and unitary space‐time coded MIMO‐OFDM scenarios are also considered.

Ricardo J Mantz - One of the best experts on this subject based on the ideXlab platform.

Zhendong Zhou - One of the best experts on this subject based on the ideXlab platform.

Yaow-ming Chen - One of the best experts on this subject based on the ideXlab platform.

  • Modeling and Controller Design of a Semiisolated Multiinput Converter for a Hybrid PV/Wind Power Charger System
    IEEE Transactions on Power Electronics, 2015
    Co-Authors: Cheng-wei Chen, Chien-yao Liao, Kun-hung Chen, Yaow-ming Chen
    Abstract:

    The objective of this paper is to propose the development of a Multiinput dc-dc converter (MIC) family, which is composed of isolated and/or nonisolated dc-dc converters. By analyzing five basic isolated dc-dc converters, four isolated pulsating voltage source cells and three isolated pulsating current source cells are generated. Moreover, a semiisolated Multiinput converter (S-MIC) for hybrid PV/wind power charger system which can simplify the power system, reduce the cost, deliver continuous power, and overcome high-voltage-transfer-ratio problems is proposed. In this paper, the operational principle of the proposed S-MIC is explained, the small-signal ac model is derived, and the controller design is developed. Computer simulations and experimental results are presented to verify the accuracy of the proposed small-signal ac model and the performance of the proposed S-MIC.

  • Multiinput converter with power factor correction, maximum power point tracking, and ripple-free input currents
    IEEE Transactions on Power Electronics, 2004
    Co-Authors: Yaow-ming Chen, Feng-yu Wu
    Abstract:

    A Multiinput converter for photovoltaic (PV) power system applications with power factor correction (PFC), maximum power point tracking (MPPT), and ripple-free input currents (RFIC) is proposed in this paper. With phase-shifted pulse-width-modulation (PWM) control, the Multiinput converter can draw power from the utility line and PV arrays individually or simultaneously and deliver it to the load. In addition, an almost unity power factor for the utility line and an MPPT for PV arrays can also be achieved. Moreover, the upper power switches of each input-stage circuit in the proposed converter are operated with zero-current-switching (ZCS) at turn-off transition and the lower ones are operated with zero-voltage-switching (ZVS) at turn-on transition. Hence, the switching losses of the power switches can be reduced. Experimental measurements are demonstrated to verify the performance of the proposed Multiinput converter.