نتایج جستجو برای: شبکه fft

تعداد نتایج: 41640  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید باهنر کرمان - دانشکده فنی 1393

یکی از مهم ترین مشکلات سیستم های ofdm عدم توانایی این سیستم ها در حذف سیگنال تداخل در باند فرکانسی سیگنال مطلوب می باشد. برای حذف این تداخلات از روش های شکل دهی پرتو استفاده می شود. دو روش مرسوم شکل دهی پرتو، روش pre-fft (شکل دهی پرتو در حوزه زمان) و روش post-fft (شکل دهی پرتو در حوزه فرکانس) می باشند. برای به روزرسانی وزن ها در هر دو روش راه حل های مختلفی پیشنهاد شده است که می توان همه آن ها ر...

2003
Daisuke Takahashi

A radix-16 fast Fourier transform (FFT) algorithm suitable for multiply-add instruction is proposed. The proposed radix-16 FFT algorithm requires fewer floating-point instructions than the conventional radix-16 FFT algorithm on processors that have a multiplyadd instruction. Moreover, this algorithm has the advantage of fewer loads and stores than either the radix-2, 4 and 8 FFT algorithms or t...

2017
Jin-Young Choi Taeyun Kim Hyung-Mo Kim Sang-Hoon Lee Il-sik Cho Seung-Hak Baek

OBJECTIVE To investigate the effects of frontal facial type (FFT) and sex on preferred chin projection (CP) in three-dimensional (3D) facial images. METHODS Six 3D facial images were acquired using a 3D facial scanner (euryprosopic [Eury-FFT], mesoprosopic [Meso-FFT], and leptoprosopic [Lepto-FFT] for each sex). After normal CP in each 3D facial image was set to 10° of the facial profile angl...

2014
Sateesh Kumar

The FFT processor is a critical block in all multi-carrier systems used primarily in the mobile environment. The portability requirement of these systems is mainly responsible for the need of low power FFT architectures. In this study, an efficient addressing scheme for radix-4 64 point FFT processor is presented. It avoids the modulo-r addition in the address generation; hence, the critical pa...

Journal: :Parallel Computing 1991
Paul N. Swarztrauber Roland A. Sweet William L. Briggs Henson Van Emden James S. Otto

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...

Journal: :تحقیقات مهندسی کشاورزی 0
محمود امید دانشیار گروه مکانیک ماشین های کشاورزی دانشکده مهندسی و فناوری کشاورزی دانشگاه تهران اصغر محمودی استادیار گروه مکانیک ماشین های کشاورزی دانشگاه تبریز مهدی علی اکبری دانشجوی سابق کارشناسی ارشد اسدالله اکرم استادیار گروه مکانیک ماشین های کشاورزی دانشکده مهندسی و فناوری کشاورزی دانشگاه تهران

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...

ژورنال: :فناوری اطلاعات و ارتباطات ایران 0
ذاکر حسین فیروزه zakerhosein firouzeh school of electrical and computer engineering, isfahan universityدانشکده مهندسی برق و کامپیوتر، دانشگاه صنعتی اصفهان ابوالقاسم زیدآبادی نژاد abolghasem zeidaabadi-ezhad school of electrical and computer engineering, isfahan universityدانشکده مهندسی برق و کامپیوتر، دانشگاه صنعتی اصفهان حمید میرمحمد صادقی hamid mirmohammad-sadeghi isfahan university of technologyپژوهشکده فناوری اطلاعات و ارتباطات، دانشگاه صنعتی اصفهان

چکیده normal 0 false false false en-us x-none ar-sa microsoftinternetexplorer4

2006
Tze-Yun Sung

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 (...

2014
N. Amarnath Reddy D. Srinivasa Venkata Suman

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 ...

Journal: :IEEE Trans. Instrumentation and Measurement 1998
Ediz Çetin Richard C. S. Morling Izzet Kale

This paper describes in detail the design of a CMOS custom fast Fourier transform (FFT) processor for computing a 256-point complex FFT. The FFT is well-suited for realtime spectrum analysis in instrumentation and measurement applications. The FFT butterfly processor reported here consists of one parallel–parallel multiplier and two adders. It is capable of computing one butterfly computation e...

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