THE BLOCK LMS ALGORITHM AND ITS FFT BASED FAST IMPLEMENTATION NEW EFFICIENT REALIZATION USING BLOCK FLOATING POINT ARITHMETIC

摘要

An effcient scheme is proposed for implementing the block LMS algorithm in a block floating point framework that per- mits processing of data over a wide dynamic range at a pro- cessor complexity and cost as low as that of a fixed point processor. The proposed scheme adopts appropriate formats for representing the filter coeflcients and the data. Using these and a new upper bound on the step size, update re- lations for the filter weight mantissas and exponent are de- veloped, taking care so that neither overflow occurs, nor are quantities which are already very small multiplied directly. It is further shown how the mantissas of the filter coe±cients and also the filter output can be evaluated faster by suitably modifying the approach of the fast block LMS algorithm. Index Terms Block LMS (BLMS), Fast BLMS, Block Floating Point, Overflow.