Higher Order Statistics for Estimation of Degree of Noncausality in Active Noise Control System

Abstract

The paper highlights the effects of degree of noncausality in the performance of single channel Active Noise Control (ANC) system. It is shown that for the optimal positioning of the secondary source (loudspeaker) the degree of noncausality calculation is important. It is also restated that the empirical formula found by Elliot et al [1,2] for the maximum convergence coefficient, which is used in the filtered-x LMS algorithm, is important to be evaluated. Hence to evaluate the degree of noncausality and to find out the Elliot's approximate convergence coefficient, the primary and the secondary path delays are required to be estimated apriori. A novel higher order statistics (HOS) based method is proposed which is efficient to estimate the time delay or sample delay of the acoustic primary path as well as the electro-acoustic secondary path even in the presence of measurement noise with small data length.

Indexing terms:

• ANC
• Degree of noncausality
• Delay estimation
• HOS
• Cumulants
• Convergence coefficient

Additional information

Notes on contributors

G Panda

G Panda received B Sc Engg degree in Electrical Engg in 1971 and MSc engg degree in Communication System in 1977 from Sambalpur University. He was awarded PhD degree in digital signal processing from IIT, Kharagpur in 1982. He served as a Lecturer from 1972 to 1979, as a Reader from 1979 to 1988 both at University College of Engg, Burla. He then joined as a Professor and Head in the Applied Electronics and Instrumentation Engineering Department of National Institute of Technology (formerly A REC), Rourkela, Orissa in 1988 and continuing till date. During 1984–86 he was a postdoctoral fellow at University of Edinburgh, UK, under Common Wealth fellowship program, specializing in adaptive signal processing.

He has successfully completed many research and developmental projects sponsored by various agencies. He has published more than 50 papers in referred journals and more than 100 papers in various national and international conferences. Eleven students have already completed doctoral works under his guidance. His research interests are in the field of digital signal processing, digital communication, soft computing and intelligent instrumentation.

He is a Fellow of National Academy of Engineers, Institution of Electronics, and Telecommunication Engineers, Institution of Engineers (INDIA); Senior member IEEE, USA; and life members of CSI and ISTE.

D P Das

D P Das received BSc degree in Physics from Utkal University, MSc degree in Electronics from Sambalpur University in 1996 and 1998, respectively. He is currently pursuing his PhD degree at National Institute of Technology, Rourkela in the field of Active Noise Control.

His research interests are Active Noise Control, DSP, Soft computing, VLSI design, and Development of embedded systems using microcontroller and FPGA.

He has published many research papers in referred journals and conferences.