EURASIP Journal on Applied Signal Processing, special issue on Design Methods for DSP Systems, vol. 2006, special no. 5, 14 pages, Article Id 92849, 2006.

Wordlength Optimization Using Sensitivity Information

Kyungtae Han and Brian L. Evans

Embedded Signal Processing Laboratory, Wireless Networking and Communications Group, The University of Texas at Austin, Austin, TX 78712 USA -

Paper - Software - Wordlength Reduction


Many digital signal processing algorithms are first developed in floating point and later converted into fixed point for digital hardware implementation. During this conversion, more than 50% of the design time may be spent for complex designs, and optimum wordlengths are searched by trading off of hardware complexity for arithmetic precision at system outputs. We propose a fast algorithm for searching for an optimum wordlength. This algorithm uses sensitivity information of hardware complexity and system output error with respect to the signal wordlengths, while other papers use only one of the two sensitivities. This paper presents various optimization methods, and compares sensitivity search methods. Wordlength design case studies for a wireless demodulator show that the proposed method can find an optimum solution in one of fourth the time that the local search method takes. In addition, the optimum wordlength searched by the proposed method has 30% lower complexity than the sequential search method in wireless demodulators. Case studies demonstrate the proposed method is robust for searching optimum wordlength in a non-convex space.

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Last Updated 05/21/06.