The Nonuniform Discrete Fourier Transform and Its Applications in Signal Processing

The Nonuniform Discrete Fourier Transform and its Applications in Signal Processing is organized into seven chapters. Chapter 1 introduces the problem of computing frequency samples of the z-transform of a finite-length sequence, and reviews the existing techniques. Chapter 2 develops the basics of the NDFT including its definition, properties and computational aspects. The NDFT is also extended to two dimensions. The ideas introduced here are utilized to develop applications of the NDFT in the following four chapters. Chapter 3 proposes a nonuniform frequency sampling technique for designing 1-D FIR digital filters. Design examples are presented for various types of filters. Chapter 4 utilizes the idea of the 2-D NDFT to design nonseparable 2-D FIR filters of various types. The resulting filters are compared with those designed by other existing methods and the performances of some of these filters are investigated by applying them to the decimation of digital images. Chapter 5 develops a design technique for synthesizing antenna patterns with nulls placed at desired angles to cancel interfering signals coming from these directions. Chapter 6 addresses the application of the NDFT in decoding dual-tone multi-frequency (DTMF) signals and presents an efficient decoding algorithm based on the subband NDFT (SB-NDFT), which achieves a fast, approximate computation of the NDFT. Concluding remarks are included in Chapter 7. The Nonuniform Discrete Fourier Transform and its Applications in Signal Processing serves as an excellent reference for researchers.