Comparison of Fixed-Point Arithmetic Errors for the FPGA-Based CRAIMOT Basis Function Generators

Author

Terauds, Maris ; Valters, Gatis ; Derums, Uldis ; Vasilevskis, Nauris ; Misans, Peteris

Author_Institution

Fac. of Electron. & Telecommun., Riga Tech. Univ., Riga, Latvia

fYear

2008

fDate

16-17 Nov. 2008

Firstpage

108

Lastpage

113

Abstract

This paper describes the mean square error (MSE) of basis function (BF) caused by the quantization of sine/cosine values. MSEs for all CRAIMOT BFs are equal. Additionally, MSEs are estimated for random signals synthesized by a limited number of weighted CRAIMOT BFs (partial sum). Maximal and minimal MSEs are given in dependence on the wordlength of sine/cosine former and the number of BFs used for synthesis. Synthesis error is independent of the number of BFs, practically constant. Errors are compared for two versions of FPGA implemented BF generator and synthesizer. Versions of mentioned devices differ by sine/cosine former blocks implemented using CORDIC and optimal linear interpolation algorithms. A CORDIC former ensures approximately twice better accuracy. A preliminary simulation has been conducted and it has proved the existence of optimal angles (optimal transforms) from the implementation point of view.

Keywords

field programmable gate arrays; fixed point arithmetic; function generators; interpolation; matrix algebra; mean square error methods; transforms; CORDIC; FPGA-based CRAIMOT basis function generator; MSE; constant rotation angle; cosine value quantization; fixed-point arithmetic; matrix orthogonal transform; mean square error; optimal linear interpolation algorithm; sine value quantization; Algorithm design and analysis; Discrete cosine transforms; Error analysis; Field programmable gate arrays; Fixed-point arithmetic; Interpolation; Quantization; Signal generators; Signal synthesis; Speech synthesis; CORDIC algorithm; FPGA; Fixed-point errors; Generation of basis functions;

fLanguage

English

Publisher

ieee

Conference_Titel

NORCHIP, 2008.

Conference_Location

Tallinn

Print_ISBN

978-1-4244-2492-4

Electronic_ISBN

978-1-4244-2493-1

Type

conf

DOI

10.1109/NORCHP.2008.4738293

Filename

4738293