The original Cooley-Tukey FFT was published in 1965 and presented for sequences with length N equal to a power of two. However, in the same paper they noted that their algorithm could be generalized to composite N in which the length of the sequence was a product of small primes. In 1967, Bergland presented an algorithm for composite N and variants of his mixed radix FFT are currently in wide u...

This study quantified normal age-related changes to the photoreceptor axons in the central macula using the birefringent properties of the Henle fiber layer. A scanning laser polarimeter was used to acquire 15° × 15° macular images in 120 clinically normal subjects, ranging in age from the third decade to the eighth. Raw image data of the macular cross were used to compute phase retardation map...

in this study, an intelligent system for sorting closed shell and open shell pistachio nuts, was designed and developed based on combined acoustic and artificial neural network (ann) techniques. the system included a microphone, pc, material handling equipment and an air reject pneumatic mechanism. the microphone, placed under the steel plate, received sound signals generated by the pistachio n...

In digital signal processing applications, we usually use DFT (discrete Fourier transform) to transfer signal from time-domain to frequency-domain. In past decades, there were many papers discussing and exploiting FFT (fast Fourier transform) architectures for hardware implementation. In this paper, we proposed a novel VLSI FFT processor based on parallel-pipelined constant geometry algorithm (...

A parallel and pipelined Fast Fourier Transform (FFT) processor for use in the Orthogonal Frequency division Multiplexer (OFDM) and WLAN, unlike being stored in the traditional ROM. The twiddle factors in our pipelined FFT processor can be accessed directly. A novel simple address mapping scheme and the modified radix 4 FFT also proposed. FPGA was majorly used to develop the ASIC IC’s to which ...

We have developed a high-performance FFT on SGI Altix 3700, improving the efficiency of the floating-point operations required to compute FFT by using a kind of loop fusion technique. As a result, we achieved a performance of 4.94 Gflops at 1-D FFT of length 4096 with an Itanium 2 1.3 GHz (95% of peak), and a performance of 28 Gflops at 2-D FFT of 4096 with 32 processors. Our FFT kernel outperf...