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Approximate Signal Processing
, 1997
"... It is increasingly important to structure signal processing algorithms and systems to allow for trading off between the accuracy of results and the utilization of resources in their implementation. In any particular context, there are typically a variety of heuristic approaches to managing these tra ..."
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Cited by 516 (2 self)
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It is increasingly important to structure signal processing algorithms and systems to allow for trading off between the accuracy of results and the utilization of resources in their implementation. In any particular context, there are typically a variety of heuristic approaches to managing these tradeoffs. One of the objectives of this paper is to suggest that there is the potential for developing a more formal approach, including utilizing current research in Computer Science on Approximate Processing and one of its central concepts, Incremental Refinement. Toward this end, we first summarize a number of ideas and approaches to approximate processing as currently being formulated in the computer science community. We then present four examples of signal processing algorithms/systems that are structured with these goals in mind. These examples may be viewed as partial inroads toward the ultimate objective of developing, within the context of signal processing design and implementation,...
Gauss and the History of the Fast Fourier Transform,” Archive for History of Exact Sciences
, 1985
"... The fast FOURIER transform (FFT) has become well known as a very efficient algorithm for calculating the discrete FOURIER transform (DFT)a formula for evaluating the N FOURIER coefficients from a sequence of N numbers. The DFT is used in many disciplines to obtain the spectrum or frequency content ..."
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Cited by 52 (0 self)
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The fast FOURIER transform (FFT) has become well known as a very efficient algorithm for calculating the discrete FOURIER transform (DFT)a formula for evaluating the N FOURIER coefficients from a sequence of N numbers. The DFT is used in many disciplines to obtain the spectrum or frequency content of a signal
An efficient implementation of NCOFDM transceivers for cognitive radios
 in Proc. of 1st Conf. on Cognitive Radio Oriented Wireless Networks and Commun., Mykonos
, 2006
"... In this paper, we present an efficient implementation of a noncontiguous orthogonal frequency division multiplexing (NCOFDM) transceiver for cognitive radio systems. NCOFDM is designed to transmit information in the presence of incumbent users, deactivating subcarriers located in the vicinity of ..."
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Cited by 29 (1 self)
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In this paper, we present an efficient implementation of a noncontiguous orthogonal frequency division multiplexing (NCOFDM) transceiver for cognitive radio systems. NCOFDM is designed to transmit information in the presence of incumbent users, deactivating subcarriers located in the vicinity of these users to avoid interference. Given that the core component of an NCOFDM transceiver is the fast Fourier transform (FFT), and that several of the subcarriers are deactivated, it is possible to reduce the execution time by “pruning ” the FFT. We propose an algorithm that efficiently and quickly prunes the FFT for NCOFDM transceivers. Results show that the proposed algorithm substantially outperforms other FFT pruning algorithms when a medium to large number of subcarriers have been deactivated. 1
Generalized multichannel frequencydomain adaptive filtering: efficient realization and application to handsfree speech communication
, 2005
"... ..."
An efficient FFT for OFDM based cognitive radio on a reconfigurable architecture
 in Communications, ICC '07. IEEE International Conference
, 2007
"... Abstract — Cognitive Radio is a promising technology to utilize nonused parts of the spectrum that actually are assigned to licensed services. An adaptive OFDM based Cognitive Radio system has the capacity to nullify individual carriers to avoid interference to the licensed user. Therefore, there c ..."
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Cited by 11 (3 self)
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Abstract — Cognitive Radio is a promising technology to utilize nonused parts of the spectrum that actually are assigned to licensed services. An adaptive OFDM based Cognitive Radio system has the capacity to nullify individual carriers to avoid interference to the licensed user. Therefore, there could be a considerably large number of zerovalued inputs/outputs for the IFFT/FFT in the OFDM transceiver. Due to the wasted operations on zero values, the standard FFT is no longer efficient. Based on this observation, we propose to use a computationally efficient IFFT/FFT as an option for OFDM based Cognitive Radio. Mapping this algorithm onto a reconfigurable architecture is discussed. I.
An Algorithm Design Environment for Signal Processing
, 1989
"... The computer is used in signal processing primarily for numerical calculations. Recently, a number of signalprocessing environments have evolved which simplify the initial creation of a signalprocessing algorithm from a series of lowlevel signalprocessing blocks. Despite this progress, the maj ..."
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Cited by 10 (0 self)
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The computer is used in signal processing primarily for numerical calculations. Recently, a number of signalprocessing environments have evolved which simplify the initial creation of a signalprocessing algorithm from a series of lowlevel signalprocessing blocks. Despite this progress, the majority of the design process is generally completed without computer support: the analyses of the properties of the selected algorithm are generally completed by hand as is the manipulation of the algorithm to find efficient, input/output equivalent implementations. This thesis explores some of the issues involved providing software tools for the symbolic analysis and rearrangement of signalprocessing algorithms as well as for the initial algorithm selection. A software environment is developed, supporting numeric signalprocessing computations as well as symbolic analysis and manipulation of signalprocessing expressions. The areas in which this thesis contribute lie primarily in the symbolic manipulation of signalprocessing expressions. To allow for the efficient manipulation of a variety of "regular " algorithms, such as polyphase and FFT structures, correspondence constraints
Efficient Computation of the TwoDimensional Fast Cosine Transform
, 1994
"... An extension of one of the fastest existing algorithms for the computation of the 2D discrete cosine transform is given. The algorithm can be implemented inplace requiring N 2 less memory locations and 2N 2 less data transfers for the computation of NxN DCT points compared to existing 2D FCT algori ..."
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Cited by 6 (2 self)
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An extension of one of the fastest existing algorithms for the computation of the 2D discrete cosine transform is given. The algorithm can be implemented inplace requiring N 2 less memory locations and 2N 2 less data transfers for the computation of NxN DCT points compared to existing 2D FCT algorithms. Based on the proposed algorithm, a fast pruning algorithm is derived for computing the N 0 xN 0 lowest frequency components of a length NxN discrete cosine transform, with both N and N 0 being powers of 2. The computational complexity of the algorithm is compared with the rowcolumn pruning method and experimental results on execution times are given. 1. INTRODUCTION Since its introduction, 1 the discrete cosine transform (DCT) has found wide application in image and signal processing in general and in data compression in particular. It has been adopted as part of the standards for still and moving pictures coding. 13 This is so, because it performs much like the statistically optima...
A comparison of timedomain timescale modification algorithms
 in Proc. 120 th Convention of the Audio Engineering Society
, 2006
"... This convention paper has been reproduced from the author's advance manuscript, without editing, corrections, or consideration by the Review Board. The AES takes no responsibility for the contents. Additional papers may be obtained by sending request ..."
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Cited by 5 (0 self)
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This convention paper has been reproduced from the author's advance manuscript, without editing, corrections, or consideration by the Review Board. The AES takes no responsibility for the contents. Additional papers may be obtained by sending request
A Novel FilterBank Multicarrier Scheme to Mitigate the Intrinsic Interference: Application to MIMO Systems
"... Abstract—Filterbank multicarrier (FBMC) transmission system was proposed as an alternative approach to orthogonal frequency division multiplexing (OFDM) system since it has a higher spectral efficiency. One of the characteristics of FBMC is that the demodulated transmitted symbols are accompanied b ..."
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Cited by 5 (3 self)
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Abstract—Filterbank multicarrier (FBMC) transmission system was proposed as an alternative approach to orthogonal frequency division multiplexing (OFDM) system since it has a higher spectral efficiency. One of the characteristics of FBMC is that the demodulated transmitted symbols are accompanied by interference terms caused by the neighboring transmitted data in timefrequency domain. The presence of this interference is an issue for some multipleinput multipleoutput (MIMO) schemes and until today their combination with FBMC remains an open problem. We can cite, among these techniques, the Alamouti scheme and the maximum likelihood detection (MLD) with spatial multiplexing (SM). In this paper, we shall propose a new FBMC scheme and transmission strategy in order to avoid this interference term. This proposed scheme (called FFTFBMC) transforms the FBMC system into an equivalent system formulated as OFDM regardless of some residual interference. Thus, any OFDM transmission technique can be performed straightforwardly to the proposed FBMC scheme with a corresponding complexity growth compared to the classical FBMC. First, we will develop the FFTFBMC in the case of singleinput singleoutput (SISO) configuration. Then, we extend its application to SMMIMO configuration with MLD and Alamouti coding scheme. Simulation results show that FFTFBMC can almost reach the OFDM performance, but it remains slightly outperformed by OFDM.
Probabilistic Complexity Analysis for a Class of Approximate DFT Algorithms
, 1996
"... We present a probabilistic complexity analysis of a class of multistage algorithms which incrementally refine DFT approximations. Each stage of any algorithm in this class improves the results of the previous stage by a fixed increment in one of three dimensions: SNR, frequency resolution, or frequ ..."
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Cited by 4 (3 self)
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We present a probabilistic complexity analysis of a class of multistage algorithms which incrementally refine DFT approximations. Each stage of any algorithm in this class improves the results of the previous stage by a fixed increment in one of three dimensions: SNR, frequency resolution, or frequency coverage. However, the complexity of each stage is probabilistically dependent upon certain characteristics of the input signal. Assuming that an algorithm has to be terminated before its arithmetic cost exceeds a given limit, we have formulated a method for predicting the probability of completion of each of the algorithm's stages. This analysis is useful for lowpower and realtime applications where FFT algorithms cannot meet the specified limits on arithmetic cost. I. Introduction While the palette of transforms available to the DSP system designer continues to broaden, the utility of the DFT across a broad range of applications remains unparalleled. This fact can be attributed in p...