Les performances a basse frequence d'un systeme de haut parleur a plusieurs excitateurs sont ... more Les performances a basse frequence d'un systeme de haut parleur a plusieurs excitateurs sont relies aux parametres de base des excitateurs et a leurs configurations acoustiques et electriques. On decrit des reseaux a deux et a quatre excitateurs
In this article, we discuss several useful “tricks” for estimating the square root of a number. O... more In this article, we discuss several useful “tricks” for estimating the square root of a number. Our focus will be on high-speed (minimum computations) techniques for approximating the square root of a single value as well as the square root of a sum of squares for quadrature (I/Q) vector magnitude estimation. In the world of DSP, the computation of a square root is found in many applications: calculating root mean squares, computing the magnitudes of fast Fourier transform (FFT) results, implementing automatic gain control (AGC) techniques, estimating the instantaneous envelope of a signal (AM demodulation) in digital receivers, and implementing three-dimensional (3-D) graphics algorithms. The fundamental tradeoff when choosing a particular square root algorithm is execution speed versus algo
Proceedings of ICASSP '94. IEEE International Conference on Acoustics, Speech and Signal Processing
Active acoustic attenuation uses a secondary source to control an undesired disturbance from a pr... more Active acoustic attenuation uses a secondary source to control an undesired disturbance from a primary source of sound or vibration. In this paper, a generalized recursive control system is presented that can be used to implement a variety of fully adaptive feedforward and feedback control schemes. Three recursive adaptive filters simultaneously provide improved modeling of the feedforward path, the feedback
IEEE Transactions on Acoustics, Speech, and Signal Processing
The use of infinite impulse response (IIR) adaptive filters has lagged behind that of finite impu... more The use of infinite impulse response (IIR) adaptive filters has lagged behind that of finite impulse response (FIR) adaptive filters. This has been due, in part, to the increased complexity of IIR filters and the potential for instability that exists due to the presence of poles in the transfer function. This paper discusses the use of adaptive filters for the active cancellation of acoustic noise. It is shown that IIR filters possess certain characteristics that are highly desirable for this problem. The selection of an appropriate IIR adaptive algorithm is discussed using observability considerations. It is shown that the recursive least mean square (RLMS) algorithm of Feintuch possesses significant advantages for use in a practical active attentuation system. Results are presented from computer simulations as well as an actual system using a TI TMS32010 digital signal processing microprocessor.
Les performances a basse frequence d'un systeme de haut parleur a plusieurs excitateurs sont ... more Les performances a basse frequence d'un systeme de haut parleur a plusieurs excitateurs sont relies aux parametres de base des excitateurs et a leurs configurations acoustiques et electriques. On decrit des reseaux a deux et a quatre excitateurs
In this article, we discuss several useful “tricks” for estimating the square root of a number. O... more In this article, we discuss several useful “tricks” for estimating the square root of a number. Our focus will be on high-speed (minimum computations) techniques for approximating the square root of a single value as well as the square root of a sum of squares for quadrature (I/Q) vector magnitude estimation. In the world of DSP, the computation of a square root is found in many applications: calculating root mean squares, computing the magnitudes of fast Fourier transform (FFT) results, implementing automatic gain control (AGC) techniques, estimating the instantaneous envelope of a signal (AM demodulation) in digital receivers, and implementing three-dimensional (3-D) graphics algorithms. The fundamental tradeoff when choosing a particular square root algorithm is execution speed versus algo
Proceedings of ICASSP '94. IEEE International Conference on Acoustics, Speech and Signal Processing
Active acoustic attenuation uses a secondary source to control an undesired disturbance from a pr... more Active acoustic attenuation uses a secondary source to control an undesired disturbance from a primary source of sound or vibration. In this paper, a generalized recursive control system is presented that can be used to implement a variety of fully adaptive feedforward and feedback control schemes. Three recursive adaptive filters simultaneously provide improved modeling of the feedforward path, the feedback
IEEE Transactions on Acoustics, Speech, and Signal Processing
The use of infinite impulse response (IIR) adaptive filters has lagged behind that of finite impu... more The use of infinite impulse response (IIR) adaptive filters has lagged behind that of finite impulse response (FIR) adaptive filters. This has been due, in part, to the increased complexity of IIR filters and the potential for instability that exists due to the presence of poles in the transfer function. This paper discusses the use of adaptive filters for the active cancellation of acoustic noise. It is shown that IIR filters possess certain characteristics that are highly desirable for this problem. The selection of an appropriate IIR adaptive algorithm is discussed using observability considerations. It is shown that the recursive least mean square (RLMS) algorithm of Feintuch possesses significant advantages for use in a practical active attentuation system. Results are presented from computer simulations as well as an actual system using a TI TMS32010 digital signal processing microprocessor.
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Papers by Mark Allie