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

  • an efficient 18 band quasi ansi 1 3 octave filter bank using re sampling method for digital hearing aids
    International Conference on Acoustics Speech and Signal Processing, 2014
    Co-Authors: Cheng Ye Yang, Chihwei Liu, Shyhjye Jou
    Abstract:

    This paper presents the multirate and re-sampling techniques to realize a low-delay, 18-band quasi-ANSI filter bank for digital hearing aids, which not only achieves a rather low computation complexity without a significant increase in the latency, but reduces greatly the total computation complexity for sub-band signal processing followed by the filter bank, such as noise reduction as well as wide dynamic range compression (WDRC). Researches done in the literature all focused on how to reduce the computation complexity of the filter bank. In particular, with the efficient multirate and interpolated FIR (IFIR) approaches for a 10-ms, 18-band quasi-ANSI filter bank, approximately 93% of the multiplications are saved, compared that with a straightforward parallel FIR filters architecture. However, they did not consider the computation complexity of the sub-band signal processing. In this paper, we first investigate realizing the FIR filter bank efficiently by using the multirate re-sampling techniques. To reduce the complexity, the optimized re-sampling factor for each filter band is explored carefully. Then, with the resampling technique, an efficient multirate quasi-ANSI FIR filter bank architecture is proposed. Compare to the stateof-the-art quasi-ANSI filter bank, approximately 17.7% of multiplicative complexity is reduced further and, up to 25% of the total computation complexity for sub-band signal processing followed by the filter bank is saved, but with only a slight increase in latency, i.e. 13.6 ms.

  • 10 ms 18 band quasi ansi s1 11 1 3 octave filter bank for digital hearing aids
    IEEE Transactions on Circuits and Systems, 2013
    Co-Authors: Chihwei Liu, Kuochiang Chang, Minghsu Chuang
    Abstract:

    The ANSI S1.11 1/3-octave filter bank is suitable for digital hearing aids, but its large group delay and high computational complexity complicate matters considerably. This study presents a 10-ms 18-band quasi-ANSI S1.11 1/3-octave filter bank for processing 24 kHz audio signals. We first discuss a filter order optimization algorithm to define the quasi-ANSI filters. The group delay constraint of filters is limited to 10 ms. The proposed design adopts an efficient prescription-fitting algorithm to reduce inter-band interference, enabling the proposed quasi-ANSI filter bank to compensate any type of hearing loss (HL) using the NAL-NL1 or HSE prescription formulas. Simulation results reveal that the maximum matching error in the prescriptions of the mild HL, moderate HL, and severe-to-profound HL is less than 1.5 dB. This study also investigates the complexity-effective multirate IFIR quasi-ANSI filter bank. For an 18-band digital hearing aid with a 24 kHz sampling rate, the proposed architecture eliminates approximately 93% of the multiplications and up to 74% of the storage elements, compared with a parallel FIR filters architecture. The proposed analysis filter bank (AFB) was designed in UMC 90 nm CMOS high-VT technology, and on the basis of post-layout simulations, it consumes 73 μW (@VDD=1 V). By voltage scaling (to 0.6 V), the simulation results show that the power consumption decreases to 27 μW, which is approximately 30% of that consumed by the most energy-efficient AFB available in the literature for use in hearing aids.

  • design and implementation of 18 band quasi ansi s1 11 1 3 octave filter bank for digital hearing aids
    International Symposium on VLSI Design Automation and Test, 2012
    Co-Authors: Kuochiang Chang, Minghsu Chuang, Chihwei Liu
    Abstract:

    The ANSI S1.11 1/3-octave filter bank is popular in many acoustic applications because it matches the human hearing characteristics. However, the long group delay and the high computational complexity limit the usage in hearing aids. A Quasi-ANSI S1.11 18-band 1/3-octave filter bank is proposed to reduce the group delay. With the matching error reduction method, the results show that the filter bank achieve comparable good matching between prescriptions and hearing aid response. The overall group delay is significantly reduced to 10ms compared to 78ms in the ANSI 1/3-octave filter bank design. Finally, the IFIR technique is adopted to minimize the computational complexity. For an 18-band digital hearing aid with 24 KHz sampling rate, the proposed architecture saves about 93% of multiplications and up to 74% of storage elements, comparing that with a parallel FIRs architecture. The test chip has been implemented in UMC 90 nm high-Vt CMOS technology, which consumes only 73 µW. By voltage scaling, the circuit-level simulation result exhibits that the power consumption of the test chip reduces to 27 µW, which is about 30% of that of the most energy-efficient design for digital hearing aids available in the literature.

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

  • 10 ms 18 band quasi ansi s1 11 1 3 octave filter bank for digital hearing aids
    IEEE Transactions on Circuits and Systems, 2013
    Co-Authors: Chihwei Liu, Kuochiang Chang, Minghsu Chuang
    Abstract:

    The ANSI S1.11 1/3-octave filter bank is suitable for digital hearing aids, but its large group delay and high computational complexity complicate matters considerably. This study presents a 10-ms 18-band quasi-ANSI S1.11 1/3-octave filter bank for processing 24 kHz audio signals. We first discuss a filter order optimization algorithm to define the quasi-ANSI filters. The group delay constraint of filters is limited to 10 ms. The proposed design adopts an efficient prescription-fitting algorithm to reduce inter-band interference, enabling the proposed quasi-ANSI filter bank to compensate any type of hearing loss (HL) using the NAL-NL1 or HSE prescription formulas. Simulation results reveal that the maximum matching error in the prescriptions of the mild HL, moderate HL, and severe-to-profound HL is less than 1.5 dB. This study also investigates the complexity-effective multirate IFIR quasi-ANSI filter bank. For an 18-band digital hearing aid with a 24 kHz sampling rate, the proposed architecture eliminates approximately 93% of the multiplications and up to 74% of the storage elements, compared with a parallel FIR filters architecture. The proposed analysis filter bank (AFB) was designed in UMC 90 nm CMOS high-VT technology, and on the basis of post-layout simulations, it consumes 73 μW (@VDD=1 V). By voltage scaling (to 0.6 V), the simulation results show that the power consumption decreases to 27 μW, which is approximately 30% of that consumed by the most energy-efficient AFB available in the literature for use in hearing aids.

  • design and implementation of 18 band quasi ansi s1 11 1 3 octave filter bank for digital hearing aids
    International Symposium on VLSI Design Automation and Test, 2012
    Co-Authors: Kuochiang Chang, Minghsu Chuang, Chihwei Liu
    Abstract:

    The ANSI S1.11 1/3-octave filter bank is popular in many acoustic applications because it matches the human hearing characteristics. However, the long group delay and the high computational complexity limit the usage in hearing aids. A Quasi-ANSI S1.11 18-band 1/3-octave filter bank is proposed to reduce the group delay. With the matching error reduction method, the results show that the filter bank achieve comparable good matching between prescriptions and hearing aid response. The overall group delay is significantly reduced to 10ms compared to 78ms in the ANSI 1/3-octave filter bank design. Finally, the IFIR technique is adopted to minimize the computational complexity. For an 18-band digital hearing aid with 24 KHz sampling rate, the proposed architecture saves about 93% of multiplications and up to 74% of storage elements, comparing that with a parallel FIRs architecture. The test chip has been implemented in UMC 90 nm high-Vt CMOS technology, which consumes only 73 µW. By voltage scaling, the circuit-level simulation result exhibits that the power consumption of the test chip reduces to 27 µW, which is about 30% of that of the most energy-efficient design for digital hearing aids available in the literature.

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

  • 10 ms 18 band quasi ansi s1 11 1 3 octave filter bank for digital hearing aids
    IEEE Transactions on Circuits and Systems, 2013
    Co-Authors: Chihwei Liu, Kuochiang Chang, Minghsu Chuang
    Abstract:

    The ANSI S1.11 1/3-octave filter bank is suitable for digital hearing aids, but its large group delay and high computational complexity complicate matters considerably. This study presents a 10-ms 18-band quasi-ANSI S1.11 1/3-octave filter bank for processing 24 kHz audio signals. We first discuss a filter order optimization algorithm to define the quasi-ANSI filters. The group delay constraint of filters is limited to 10 ms. The proposed design adopts an efficient prescription-fitting algorithm to reduce inter-band interference, enabling the proposed quasi-ANSI filter bank to compensate any type of hearing loss (HL) using the NAL-NL1 or HSE prescription formulas. Simulation results reveal that the maximum matching error in the prescriptions of the mild HL, moderate HL, and severe-to-profound HL is less than 1.5 dB. This study also investigates the complexity-effective multirate IFIR quasi-ANSI filter bank. For an 18-band digital hearing aid with a 24 kHz sampling rate, the proposed architecture eliminates approximately 93% of the multiplications and up to 74% of the storage elements, compared with a parallel FIR filters architecture. The proposed analysis filter bank (AFB) was designed in UMC 90 nm CMOS high-VT technology, and on the basis of post-layout simulations, it consumes 73 μW (@VDD=1 V). By voltage scaling (to 0.6 V), the simulation results show that the power consumption decreases to 27 μW, which is approximately 30% of that consumed by the most energy-efficient AFB available in the literature for use in hearing aids.

  • design and implementation of 18 band quasi ansi s1 11 1 3 octave filter bank for digital hearing aids
    International Symposium on VLSI Design Automation and Test, 2012
    Co-Authors: Kuochiang Chang, Minghsu Chuang, Chihwei Liu
    Abstract:

    The ANSI S1.11 1/3-octave filter bank is popular in many acoustic applications because it matches the human hearing characteristics. However, the long group delay and the high computational complexity limit the usage in hearing aids. A Quasi-ANSI S1.11 18-band 1/3-octave filter bank is proposed to reduce the group delay. With the matching error reduction method, the results show that the filter bank achieve comparable good matching between prescriptions and hearing aid response. The overall group delay is significantly reduced to 10ms compared to 78ms in the ANSI 1/3-octave filter bank design. Finally, the IFIR technique is adopted to minimize the computational complexity. For an 18-band digital hearing aid with 24 KHz sampling rate, the proposed architecture saves about 93% of multiplications and up to 74% of storage elements, comparing that with a parallel FIRs architecture. The test chip has been implemented in UMC 90 nm high-Vt CMOS technology, which consumes only 73 µW. By voltage scaling, the circuit-level simulation result exhibits that the power consumption of the test chip reduces to 27 µW, which is about 30% of that of the most energy-efficient design for digital hearing aids available in the literature.

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

  • an efficient 18 band quasi ansi 1 3 octave filter bank using re sampling method for digital hearing aids
    International Conference on Acoustics Speech and Signal Processing, 2014
    Co-Authors: Cheng Ye Yang, Chihwei Liu, Shyhjye Jou
    Abstract:

    This paper presents the multirate and re-sampling techniques to realize a low-delay, 18-band quasi-ANSI filter bank for digital hearing aids, which not only achieves a rather low computation complexity without a significant increase in the latency, but reduces greatly the total computation complexity for sub-band signal processing followed by the filter bank, such as noise reduction as well as wide dynamic range compression (WDRC). Researches done in the literature all focused on how to reduce the computation complexity of the filter bank. In particular, with the efficient multirate and interpolated FIR (IFIR) approaches for a 10-ms, 18-band quasi-ANSI filter bank, approximately 93% of the multiplications are saved, compared that with a straightforward parallel FIR filters architecture. However, they did not consider the computation complexity of the sub-band signal processing. In this paper, we first investigate realizing the FIR filter bank efficiently by using the multirate re-sampling techniques. To reduce the complexity, the optimized re-sampling factor for each filter band is explored carefully. Then, with the resampling technique, an efficient multirate quasi-ANSI FIR filter bank architecture is proposed. Compare to the stateof-the-art quasi-ANSI filter bank, approximately 17.7% of multiplicative complexity is reduced further and, up to 25% of the total computation complexity for sub-band signal processing followed by the filter bank is saved, but with only a slight increase in latency, i.e. 13.6 ms.

M A Mahdi - One of the best experts on this subject based on the ideXlab platform.

  • investigation on the effect of stimulated raman scattering in remotely pumped l band erbium doped fiber amplifier
    Laser Physics Letters, 2009
    Co-Authors: M Abu H Bakar, M A Mahdi, A F Abas, M Mokhtar, Md N Yusoff
    Abstract:

    The effect of stimulated Raman scattering (SRS) in remote pumping scheme for L-Band erbium-doped fiber amplifier (EDFA) was studied in this experiment. Observation was done on the gain and noise figure performance as well as the Raman distributed gains of the remotely-pumped L-Band erbium-doped fiber amplifier with the existence of SRS. The utilization of SRS effect as a secondary pump for L-Band EDFA demonstrated improvements over single pump EDFA at low pump power due to the additional power from the generated C-band stimulated Raman scattering or SRS. Nevertheless, the augmentation of the C-band SRS power as the pump was increased, caused gain competition with the L-Band signal which ultimately affected the performance of the L-Band EDFA. The Raman distributed gain was also influenced by the C-band SRS existence, which saw declining L-Band gains as the C-band SRS rose and then improved values once the C-band SRS is saturated.

  • high gain bidirectional er sup 3 doped fiber amplifier for conventional and long wavelength bands
    IEEE Photonics Technology Letters, 2000
    Co-Authors: M A Mahdi, Faisal Rafiq Mahamd Adikan, P Poopalan, S Selvakennedy, Harith Ahmad
    Abstract:

    High average gains of greater than 31 dB have been obtained between 1530-1560 nm (conventional-wavelength band, C-band) and 1570-1600 nm (long-wavelength band, L-Band) using a saturating tone technique that represents 64 channels of a wavelength division multiplexed system. A bidirectional amplifying stage is utilized as high-power C-band and low-noise L-Band stages. Noise figures of less than 3.6 and 5.4 dB are measured for the C- and L-Bands, respectively.