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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

On Generating Complex Numbers for FFT and NCO Using the CORDIC Algorithm / Att generera komplexa tal för FFT och NCO med CORDIC-algoritmen

Andersson, Anton January 2008 (has links)
<p>This report has been compiled to document the thesis work carried out by Anton Andersson for Coresonic AB. The task was to develop an accelerator that could generate complex numbers suitable for fast fourier transforms (FFT) and tuning the phase of complex signals (NCO). Of many ways to achieve this, the CORDIC algorithm was chosen. It is very well suited since the basic implementation allows rotation of 2D-vectors using only shift and add operations. Error bounds and proof of convergence are derived carefully The accelerator was implemented in VHDL in such a way that all critical parameters were easy to change. Performance measures were extracted by simulating realistic test cases and then compare the output with reference data precomputed with high precision. Hardware costs were estimated by synthesizing a set of different configurations. Utilizing graphs of performance versus cost makes it possible to choose an optimal configuration. Maximum errors were extracted from simulations and seemed rather large for some configurations. The maximum error distribution was then plotted in histograms revealing that the typical error is often much smaller than the largest one. Even after trouble-shooting, the errors still seem to be somewhat larger than what other implementations of CORDIC achieve. However, precision was concluded to be sufficient for targeted applications.</p> / <p>Den här rapporten dokumenterar det examensarbete som utförts av AntonAndersson för Coresonic AB. Uppgiften bestod i att utveckla enaccelerator som kan generera komplexa tal som är lämpliga att använda försnabba fouriertransformer (FFT) och till fasvridning av komplexasignaler (NCO). Det finns en mängd sätt att göra detta men valet föllpå en algoritm kallad CORDIC. Den är mycket lämplig då den kan rotera2D-vektorer godtycklig vinkel med enkla operationer som bitskift ochaddition. Felgränser och konvergens härleds noggrannt. Acceleratorn implementerades i språket VHDL med målet att kritiskaparametrar enkelt skall kunna förändras. Därefter simuleradesmodellen i realistiska testfall och resulteten jämfördes medreferensdata som förberäknats med mycket hög precision. Dessutomsyntetiserades en mängd olika konfigurationer så att prestanda enkeltkan viktas mot kostnad.Ur de koefficienter som erhölls genom simuleringar beräknades detstörsta erhållna felet för en mängd olika konfigurationer. Felenverkade till en början onormalt stora vilket krävde vidareundersökning. Samtliga fel från en konfiguration ritades ihistogramform, vilket visade att det typiska felet oftast varbetydligt mindre än det största. Även efter felsökning verkar acceleratorngenerera tal med något större fel än andra implementationer avCORDIC. Precisionen anses dock vara tillräcklig för avsedda applikationer.</p>

Comparison of estimates of autoregressive models with superimposed errors

Chong, Siu-yung. January 2001 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 89-94).

Computational study of the transparent window for the water beam assisted form error in-process optical measurement method /

Lai, Ying Hoi. January 2009 (has links)
Includes bibliographical references (p. 207-212).

Transparent window size study of the water beam assisted form error in-process optical measurement method /

Zhang, Yunfei. January 2009 (has links)
Includes bibliographical references (p. 199-204).

Modeling uncertainty for information extraction from speech data /

Palmer, David Donald. January 2001 (has links)
Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 121-128).

Integration of on-line data reconciliation and bias identification techniques /

Soderstrom, Tyler Andrew, January 2001 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 175-187). Available also in a digital version from Dissertation Abstracts.

Sample size calculation for testing an interaction effect in a logistic regression under measurement error model /

Lee, Michelle Oi San. January 2003 (has links)
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 66-67). Also available in electronic version. Access restricted to campus users.

Control of geometry error in hp finite element (FE) simulations of electromagnetic (EM) waves

Xue, Dong, 1977- 28 August 2008 (has links)
Not available / text

Functional magnetic resonance image registration using fourier phase and residue error detection

麥可瑩, Mak, Ho-ying. January 2002 (has links)
published_or_final_version / abstract / toc / Electrical and Electronic Engineering / Master / Master of Philosophy

Comparison of estimates of autoregressive models with superimposed errors

莊少容, Chong, Siu-yung. January 2001 (has links)
published_or_final_version / Statistics and Actuarial Science / Master / Master of Philosophy

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