Kofi M. Odame

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—In this paper, we propose a novel bandpass filter design that incorporates automatic gain control (AGC). The gain control in the filter reduces the performance requirements of a wide-band AGC, and allows for low-power multichannel compression. The filter achieves up to 15 dB of compression on a 55-dB input dynamic range and is tunable over the audio(More)
We propose a low-power, analog and mixed-mode, implementation of particle filters. Low-power analog implementation of nonlinear functions such as exponential and arctangent functions is done using multiple-input translinear element (MITE) networks. These nonlinear functions are used to calculate the probability densities in the particle filter. A(More)
—An analog sinusoidal oscillator usually involves some form of amplitude-limiting mechanism. We examine operational-transconductance-amplifier (OTA) nonlinearity as a choice for amplitude limiting and develop a general theory for its use in OTA–ca-pacitor (OTA-C) oscillators. We facilitate our theoretical discussion with an illustrative design example that(More)
— In this paper, we present a microphone preamplifier that adapts its power consumption according to the input signal's instantaneous bandwidth. The preamplifier's dynamic range and gain keep reasonably constant, regardless of the power consumption. The preamplifier was fabricated with a 0.5-µm CMOS process. The measurement results show it has over 79.5-dB(More)
In this paper, we present a real-time implementation of the ideal binary-mask algorithm, which is a promising approach for enhancing speech intelligibility. Our implementation is hardware efficient, making it suitable for embedded biomedical devices such as hearing aids and cochlear implants. We tested our algorithm implementation on an FPGA platform, and(More)
In this Letter, we propose a class of nonlinear dynamic translinear circuits as a viable tool for the rapid and systematic implementation of chaotic oscillators in analog integrated circuits. In this regard, our primary focus is on multiple-input translinear element (MITE) networks and their particular merits. We also describe, as an illustrative example,(More)
—Speech edge detection can be used to adaptively control the performance and improve the energy efficiency of smart audio sensors. In this paper, we propose a spike encoding circuit inspired by mammalian auditory system for real-time and low-power speech edge detection. The circuit can directly encode the signal's envelope information by asynchronous(More)
In this paper, we present a real-time embedded implementation of the binary masking algorithm, which has been shown to significantly improve speech-in-noise intelligibility. Our real-time implementation relies on a balance of parallel processing and hardware pipelining. We have tested and evaluated our implementation on a Spartan 3A FPGA. The measured(More)