The Experts below are selected from a list of 147762 Experts worldwide ranked by ideXlab platform

Richard Heusdens - One of the best experts on this subject based on the ideXlab platform.

  • Schemes for Optimal Frequency-differential encoding of sinusoidal model parameters
    Signal Processing, 2003
    Co-Authors: Jesper Jensen, Richard Heusdens
    Abstract:

    Sinusoidal coding plays an important role in low bit-rate audio coding. This paper considers Frequency-differential encoding of the sinusoidal model parameters as an alternative to time-differential encoding. For a given signal frame, the parameters of each sinusoidal component may be encoded either differentially relative to other components in the same frame, or directly, i.e., without differential encoding. Using basic tools from graph theory, we derive several algorithms for finding bit-rate Optimal combinations of direct and differential encoding of the sinusoidal parameters. In simulation experiments with audio signals, the algorithms showed bit-rate reductions of up to 28% relative to direct encoding. Furthermore, when compared to what can be considered a traditional FD encoding scheme (as used in MPEG-4 audio), the proposed algorithms achieve bit-rate reductions of up to 6%.

  • ICASSP - Optimal Frequency-differential encoding of sinusoidal model parameters
    IEEE International Conference on Acoustics Speech and Signal Processing, 2002
    Co-Authors: Jesper Jensen, Richard Heusdens
    Abstract:

    Sinusoidal coding has proven to be efficient for low bit-rate audio coding. In this paper we consider schemes for Frequency-differential (FD) encoding of the sinusoidal model parameters. For a given signal frame, the parameters of a sinusoidal component may be encoded either differentially relative to other components in the same frame, or directly, i.e., without differential encoding. Using basic tools from graph theory, two algorithms are derived for finding bit rate Optimal combinations of direct and differential encoding of the sinusoidal parameters. In simulation experiments with audio signals, the algorithms showed bit-rate reductions of up to 27% relative to direct encoding. Furthermore, when compared to a commonly used FD encoding scheme, the proposed algorithms achieved bit rate reductions of up to 7%.

Jesper Jensen - One of the best experts on this subject based on the ideXlab platform.

  • Schemes for Optimal Frequency-differential encoding of sinusoidal model parameters
    Signal Processing, 2003
    Co-Authors: Jesper Jensen, Richard Heusdens
    Abstract:

    Sinusoidal coding plays an important role in low bit-rate audio coding. This paper considers Frequency-differential encoding of the sinusoidal model parameters as an alternative to time-differential encoding. For a given signal frame, the parameters of each sinusoidal component may be encoded either differentially relative to other components in the same frame, or directly, i.e., without differential encoding. Using basic tools from graph theory, we derive several algorithms for finding bit-rate Optimal combinations of direct and differential encoding of the sinusoidal parameters. In simulation experiments with audio signals, the algorithms showed bit-rate reductions of up to 28% relative to direct encoding. Furthermore, when compared to what can be considered a traditional FD encoding scheme (as used in MPEG-4 audio), the proposed algorithms achieve bit-rate reductions of up to 6%.

  • ICASSP - Optimal Frequency-differential encoding of sinusoidal model parameters
    IEEE International Conference on Acoustics Speech and Signal Processing, 2002
    Co-Authors: Jesper Jensen, Richard Heusdens
    Abstract:

    Sinusoidal coding has proven to be efficient for low bit-rate audio coding. In this paper we consider schemes for Frequency-differential (FD) encoding of the sinusoidal model parameters. For a given signal frame, the parameters of a sinusoidal component may be encoded either differentially relative to other components in the same frame, or directly, i.e., without differential encoding. Using basic tools from graph theory, two algorithms are derived for finding bit rate Optimal combinations of direct and differential encoding of the sinusoidal parameters. In simulation experiments with audio signals, the algorithms showed bit-rate reductions of up to 27% relative to direct encoding. Furthermore, when compared to a commonly used FD encoding scheme, the proposed algorithms achieved bit rate reductions of up to 7%.

Teresa H. Meng - One of the best experts on this subject based on the ideXlab platform.

  • Optimal Frequency for Wireless Power Transmission
    2010
    Co-Authors: Ada S. Y. Poon, Teresa H. Meng
    Abstract:

    RF wireless interface enables remotely-powered im- plantable devices. Current studies in wireless power transmission into biological tissue tend to operate below 10 MHz due to tissue absorption loss, which results in large receive antennas. This paper examines the range of frequencies that will optimize the tradeoff between received power and tissue absorption. It first models biological tissue as a dispersive dielectric in a homoge- neous medium and performs full-wave analysis to show that the Optimal Frequency is above 1 GHz for small receive coil and typical transmit-receive separations. Then, it includes the air-tissue inter- face and models human body as a planarly layered medium. The Optimal Frequency is shown to remain in the GHz-range. Finally, electromagnetic simulations are performed to include the effect of load impedance and look at the matched power gain. The Optimal Frequency is in the GHz-range for mm-sized transmit antenna and shifts to the sub-GHz range for cm-sized transmit antenna. The multiple orders of magnitude increase in the operating Frequency enables dramatic miniaturization of implantable devices. Index Terms—Implantable medical devices, wireless power transfer.

  • Optimal Frequency for Wireless Power Transmission Into Dispersive Tissue
    IEEE Transactions on Antennas and Propagation, 2010
    Co-Authors: Ada S. Y. Poon, Stephen O'driscoll, Teresa H. Meng
    Abstract:

    RF wireless interface enables remotely-powered implantable devices. Current studies in wireless power transmission into biological tissue tend to operate below 10 MHz due to tissue absorption loss, which results in large receive antennas. This paper examines the range of frequencies that will optimize the tradeoff between received power and tissue absorption. It first models biological tissue as a dispersive dielectric in a homogeneous medium and performs full-wave analysis to show that the Optimal Frequency is above 1 GHz for small receive coil and typical transmit-receive separations. Then, it includes the air-tissue interface and models human body as a planarly layered medium. The Optimal Frequency is shown to remain in the GHz-range. Finally, electromagnetic simulations are performed to include the effect of load impedance and look at the matched power gain. The Optimal Frequency is in the GHz-range for mm-sized transmit antenna and shifts to the sub-GHz range for cm-sized transmit antenna. The multiple orders of magnitude increase in the operating Frequency enables dramatic miniaturization of implantable devices.

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

  • Optimal Frequency Hopping Sequences of Odd Length
    IEEE Transactions on Information Theory, 2013
    Co-Authors: Xiangyong Zeng, Han Cai, Xiaohu Tang, Yang Yang
    Abstract:

    In this paper, a new generalized cyclotomy with respect to a positive odd integer is introduced, and a construction of Frequency hopping sequence sets and two constructions of Frequency hopping sequences are proposed as its applications. The Frequency hopping sequence sets and Frequency hopping sequences obtained in this paper can be Optimal with respect to the Peng-Fan bound and Lempel-Greenberger bound, respectively. Further, the length of sequences in the Optimal Frequency hopping sequence sets can be any odd integer larger than 3. Some of them have new parameters.

  • A Class of Optimal Frequency Hopping Sequences with New Parameters
    IEEE Transactions on Information Theory, 2012
    Co-Authors: Xiangyong Zeng, Han Cai, Xiaohu Tang, Yang Yang
    Abstract:

    In this paper, we propose an interleaving construction of new sets of Frequency hopping sequences from the known ones. By choosing suitable known Optimal Frequency hopping sequences and sets of Frequency hopping sequences and then recursively applying the proposed construction, Optimal Frequency hopping sequences and sets of Frequency hopping sequences with new parameters can be obtained.

Ada S. Y. Poon - One of the best experts on this subject based on the ideXlab platform.

  • Optimal Frequency for Wireless Power Transmission
    2010
    Co-Authors: Ada S. Y. Poon, Teresa H. Meng
    Abstract:

    RF wireless interface enables remotely-powered im- plantable devices. Current studies in wireless power transmission into biological tissue tend to operate below 10 MHz due to tissue absorption loss, which results in large receive antennas. This paper examines the range of frequencies that will optimize the tradeoff between received power and tissue absorption. It first models biological tissue as a dispersive dielectric in a homoge- neous medium and performs full-wave analysis to show that the Optimal Frequency is above 1 GHz for small receive coil and typical transmit-receive separations. Then, it includes the air-tissue inter- face and models human body as a planarly layered medium. The Optimal Frequency is shown to remain in the GHz-range. Finally, electromagnetic simulations are performed to include the effect of load impedance and look at the matched power gain. The Optimal Frequency is in the GHz-range for mm-sized transmit antenna and shifts to the sub-GHz range for cm-sized transmit antenna. The multiple orders of magnitude increase in the operating Frequency enables dramatic miniaturization of implantable devices. Index Terms—Implantable medical devices, wireless power transfer.

  • Optimal Frequency for Wireless Power Transmission Into Dispersive Tissue
    IEEE Transactions on Antennas and Propagation, 2010
    Co-Authors: Ada S. Y. Poon, Stephen O'driscoll, Teresa H. Meng
    Abstract:

    RF wireless interface enables remotely-powered implantable devices. Current studies in wireless power transmission into biological tissue tend to operate below 10 MHz due to tissue absorption loss, which results in large receive antennas. This paper examines the range of frequencies that will optimize the tradeoff between received power and tissue absorption. It first models biological tissue as a dispersive dielectric in a homogeneous medium and performs full-wave analysis to show that the Optimal Frequency is above 1 GHz for small receive coil and typical transmit-receive separations. Then, it includes the air-tissue interface and models human body as a planarly layered medium. The Optimal Frequency is shown to remain in the GHz-range. Finally, electromagnetic simulations are performed to include the effect of load impedance and look at the matched power gain. The Optimal Frequency is in the GHz-range for mm-sized transmit antenna and shifts to the sub-GHz range for cm-sized transmit antenna. The multiple orders of magnitude increase in the operating Frequency enables dramatic miniaturization of implantable devices.