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  • Research Article
  • Open Access

An Efficient Implementation of the Sign LMS Algorithm Using Block Floating Point Format

  • 1Email author,
  • 1 and
  • 2
EURASIP Journal on Advances in Signal Processing20072007:057086

  • Received: 11 July 2005
  • Accepted: 24 November 2006
  • Published:


An efficient scheme is presented for implementing the sign LMS algorithm in block floating point format, which permits processing of data over a wide dynamic range at a processor complexity and cost as low as that of a fixed point processor. The proposed scheme adopts appropriate formats for representing the filter coefficients and the data. It also employs a scaled representation for the step-size that has a time-varying mantissa and also a time-varying exponent. Using these and an upper bound on the step-size mantissa, update relations for the filter weight mantissas and exponent are developed, taking care so that neither overflow occurs, nor are quantities which are already very small multiplied directly. Separate update relations are also worked out for the step size mantissa. The proposed scheme employs mostly fixed-point-based operations, and thus achieves considerable speedup over its floating-point-based counterpart.


  • Information Technology
  • Quantum Information
  • Efficient Scheme
  • Efficient Implementation
  • Filter Coefficient

Authors’ Affiliations

Department of Electronics and Electrical Communication Engineering, Indian Institute of Technology, Kharagpur, 721302, India
Department of Information and Communication, Chonbuk National University, Chonju, 561756, South Korea


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© Chakraborty et al. 2007