Performance analysis of Discrete Cosine Transform in Multibeamforming
Date
2015-09-15
Authors
Journal Title
Journal ISSN
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ORCID
Type
Thesis
Degree Level
Masters
Abstract
Aperture arrays are widely used in beamforming applications where element signals are steered to a particular direction of interest and a single beam is formed. Multibeamforming is an extension of single beamforming, which is desired in the fields where sources located in multiple directions are of interest. Discrete Fourier Transform (DFT) is usually used in these scenarios to
segregate the received signals based on their direction of arrivals. In case of broadband signals,
DFT of the data at each sensor of an array decomposes the signal into multiple narrowband signals. However, if hardware cost and implementation complexity are of concern while maintaining the desired performance, Discrete Cosine Transform (DCT) outperforms DFT.
In this work, instead of DFT, the Discrete Cosine Transform (DCT) is used to decompose
the received signal into multiple beams into multiple directions. DCT offers simple and efficient hardware implementation. Also, while low frequency signals are of interest, DCT can process correlated data and perform close to the ideal Karhunen-Loeve Transform (KLT).
To further improve the accuracy and reduce the implementation cost, an efficient technique using Algebraic Integer Quantization (AIQ) of the DCT is presented. Both 8-point and
16-point versions of DCT using AIQ mapping have been presented and their performance is
analyzed in terms of accuracy and hardware complexity. It has been shown that the proposed AIQ DCT offers considerable savings in hardware compared to DFT and classical DCT while maintaining the same accuracy of beam steering in multibeamforming application.
Description
Keywords
Beamforming, Discrete Cosine Transform, Multibeamforming, Algebraic Integer, 16 point AIQ DCT
Citation
Degree
Master of Science (M.Sc.)
Department
Electrical and Computer Engineering
Program
Electrical Engineering