Showing papers in "IEEE Assp Magazine in 1988"
TL;DR: An overview of beamforming from a signal-processing perspective is provided, with an emphasis on recent research.
Abstract: An overview of beamforming from a signal-processing perspective is provided, with an emphasis on recent research. Data-independent, statistically optimum, adaptive, and partially adaptive beamforming are discussed. Basic notation, terminology, and concepts are included. Several beamformer implementations are briefly described. >
4,122 citations
TL;DR: Three distinct techniques for dealing with pipelining, namely, interlocking, time-stationary coding, and data-stationaries coding, are examined and their effects on performance and the impact on the user are studied.
Abstract: The architectural features of single-chip programmable digital signal processors (DSPs) are explored. The focus is on the most basic such feature, the integration of a hardware multiplier/accumulator into the data path, and a more subtle feature, the use of several (up to six) independent memory banks. These features are studied in terms of the performance benefit and the impact on the user. Representative DSPs from three manufacturers AT&T Motorola, and Texas Instruments are used to illustrate the ideas to compare different solutions to the same problems. >
203 citations
TL;DR: In this article, the authors show that the Householder transforms can be viewed as mirror-image reflections of a data vector about any desired hyperplane, and that these reflections are covariance invariant, that is, they preserve the covariance matrix of the data.
Abstract: The author explores Householder transforms and their applications in signal processing. He shows that these transforms can be viewed as mirror-image reflections of a data vector about any desired hyperplane. The virtue of reflections is that they are covariance invariant, that is, they preserve the covariance matrix of the data. One can construct a finite sequence of such reflections that maps a block of data vectors into a lower rectangular matrix. If only the covariance eigenvalues need to be preserved, one can map into a bidiagonal matrix. The former sparse form is useful for inverting covariance matrices and the latter is useful in finding eigenvalues of covariance matrices. >
69 citations
TL;DR: Preliminary results are presented on the VLSI design and implementation of a novel algorithm for accurate high-speed Fourier analysis and synthesis, based on the number-theoretic method of Mobius inversion.
Abstract: Preliminary results are presented on the VLSI design and implementation of a novel algorithm for accurate high-speed Fourier analysis and synthesis. The arithmetic Fourier transform (AFT) is based on the number-theoretic method of Mobius inversion. Its computations proceed in parallel, and the individual operations are very simple. Except for a small number of scalings in one state of the computation, only multiplications by 0, +1, and -1 are required. If the input samples were not quantized and if ideal real-number operations were used internally, then the results would be exact. The accuracy of the computation is limited only by the input A/D (analog-to-digital) conversion process, any constraints on the word lengths of internal accumulating registers, and the implementation of the few scaling operations. Further simplifications are obtained by using delta modulation to represent the input function in digital form, so that only binary (or preferably, ternary) sequences needs to be processed in the parallel computations. The required accumulations can be replaced by up/down counters. The dynamic range of the resulting transformation can be increased by the use of adaptive delta modulation. >
63 citations
TL;DR: A brief overview of the role of integers and integer relationships in the science is given in this article, where the effectiveness of discrete mathematics in physics, music, and communication (and its negation, cryptography) is examined.
Abstract: A brief overview is given of the role of integers and integer relationships in the science. The effectiveness of discrete mathematics in physics, music, and communication (and its negation, cryptography) is examined. The discussion covers: numbers and musical scales; concert halls and quadratic residues; wave diffraction and primitive roots; forbidding property of Fermat primes; Euler totients and cryptography; uses of finite fields; error correction codes from Galois fields; correlation and Fourier properties of Galois sequences; Galois sequences and the fourth effect of general relativity; and Chinese remainders feed fast algorithm. >
9 citations