Development of an Adaptive Block Filter Structure using Rectangular Transform

Abstract

Recently it was shown that the rectangular transform (RT), an efficient circular convolution algorithm, offers significant computational advantage over the fast Fourier transform (FFT) when used to implement a circular convolution adaptive filter. This observation as well as its potential in fixed filtering applications have motivated the present investigation of the development of an RT based linear convolution block adaptive finite impulse response (FIR) digital filter. Unlike the existing FFT and Fermat number transform (FNT) based block adaptive filter structures, which exploit their respective transform properties, the present formulation yields a more general efficient structure which does not rely on the properties of a particular circular convolution algorithm. To achieve both the computational efficiency and saving in memory, the existing RT has been modified. A condition for optimum ordering of the short RT modules which results in an overall minimum computational load is also derived. An evaluation of the computational requirements shows that for moderate order filters the proposed structure is a useful alternative to its FFT implementation. To justify the validity of the technique presented, the convergence properties of the filter for both white and correlated inputs are also studied through simulation.

Indexing terms:

• Adaptive filtering
• Transform domain
• Filter structure

Additional information

Notes on contributors

G Panda

Ganapati Panda obtained first class degree with honours in Electrical Engineering in 1971 and MSc Engg in Communication Systems in 1977 from Sambalpur University. He received PhD degree in Digital Signal Processing in 1982 from IIT, Kharagpur. He was awarded Commonwealth Academic Fellowship and pursued post-doctoral work in “Adaptive Signal Processing” at University of Edinburg UK, during 1984–86. He was a Lecturer (1972–79), a Reader (1979–88) at University College of Engineering, Burla, in 1988 he joined Regional Engineering College, Rourkela as Professor and is the founder Head of the Dept of Applied Electronics and Instrumentation Engineering. He is continuing in this post till date.

He has published more than 100 research papers in conferences and reputed journals. He has also edited a book on “Digital Signal Processing”. He has been honoured with Samanta Chandra Sekhar award for outstanding contribution to Engineering and Technology by Govt. of Orissa in 1993. He is a reviewer of IEE Proceeding (UK) and IEEE Transactions (USA). He is a Life Fellow of Institute of Engineers, India, Life Member of CSI, Life Member of ISTE and senior member of IEEE (USA). He has visited USA, UK, France, Japan and Singapore on various academic assignments.

K C Mahapatra

Krishna Chandra Mohapatra obtained BSc degree with first class honours and distinction in 1981, MSc Physics with special paper Electronics in 1983 from Utkal University. He joined as a lecturer in Physics and Electronics in Stewart Science College, Cuttack in 1984 and is continuing till date.

He has presented papers in conferences and published papers in reputed journals. His field of interest is electronics circuits and digital signal processing.