NASA Scientific and Technical Aerospace Reports

20060001681 University of Southwestern Louisiana, Lafayette, LA, USA
A Quadratic Residue Processor for Complex DSP Applications
Bayoumi, Magdy A.; IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP ‘87); Volume 1;
1987, pp. 475-478; In English; See also 20060001583; Copyright; Avail.: Other Sources
The performance requirements for high speed realtime Digital Signal Processing (DSP) applications, coupled with the
hardware complexity for manipulating data over complex fields can often exceed the capacity of the traditional signal
processors. In this paper, a signal processor for complex DSP applications has been developed. It is based on using the
Quadratic Residue Number System (QRNS) which establishes parallelism on the functional level and optimizes the required
hardware. By employing QRNS, the interaction between the real and imaginary channels in complex arithmetic is eliminated,
and two real multiplications are only required to perform complex multiplication. The processor design is optimized for
efficient computation of the FFT and signal processing operations based on FFT such as FIR filtering, IFFT, convolution,
correlation and multiplication. This computational versatility is’achieved through macroprogrammability. FIFO’s First-in
First-out) are used for storing the input, intermediate, and output data (and coefficients). Customized look-up tables are
employed for implementing the residue operations. The developed processor can be employed either as a stand-alone
processor or as a peripheral processor (Co-processor).
Author
Signal Processing; Signal Analyzers
20060001682 Cornell Univ., Ithaca, NY, USA
A Bit-Serial Floating-Point Complex Multiplier-Accumulator for Fault-Tolerant Digital Signal Processing Arrays
Chau, Paul M.; Chew, Kay C.; Ku, Walter H.; IEEE International Conference on Acoustics, Speech, and Signal Processing
(ICASSP ‘87); Volume 1; 1987, pp. 483-486; In English; See also 20060001583; Copyright; Avail.: Other Sources
This paper presents the extension of bit-serial architectures for next-generation signal processing chips with floating-point
and fault-tolerant capabilities. The architecture and design of a novel bit-serial floating-point complex multiplier-accumulator
CMAC) hardware is described. Fault-tolerant features are incorporated by embedding these CMACs into dynamically
reconfigurable systolic arrays. The arrays can be utilized for FIR filtering, convolution, correlation and other signal processing
applications based upon multiply-accumulate. Furthermore, these computational cores can be incorporated into more complex
processors which perform FFT-type computations. With the advent of submicron VLSI technology, the smaller device
geometries will afford either the implementation of greater functionality and/or computational capabilities. These increased
capabilities will enable the solution of more demanding signal processing problems where there exist broad dynamic range
requirements or low signal to noise conditions. But also associated with the increased functionality is the greater need for fault
tolerance in high performance applications. Our bit-serial floating-point complex multiplier-accumulator wi11 serve many
such signal processing needs.
Author
Accumulators; Computer Techniques; Fast Fourier Transformations; Floating Point Arithmetic; Signal Processing
20060001683 Erlangen-Nuernberg Univ., Erlangen, Germany
OCF-A New Coding Algorithm for High Quality Sound Signals
Brandenburg, Karlheinz; IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP ‘87); Volume
1; 1987, pp. 5.1.1 - 5.1.4; In English; See also 20060001583; Copyright; Avail.: Other Sources
Optimum Coding in the Frequency domain (0CF) uses entropy coding of quantized spectral coefficients to efficiently code
high quality sound signals with 3 bits/sample. In an iterative algorithm psychoacoustic weighting is used to get the
quantization noise to be masked in every critical band. The coder itself uses iterative quantizer control to get each data block
to be coded with a fixed number of bits. Details about the OCF-Coder are presented together with information about the
codebook needed and the training for the entropy coder. An algorithm for calculating a noise-to-mask ratio is presented which
helps to identify, where quantization noise could be audible.
Author
Algorithms; Coders; Hearing; Frequencies; Coding
20060001685 Institute of Sound and Vibration Research, Southampton, UK
Casual Constraints on the Active Control of Sound
Nelson, P. A.; Hammond, J. K.; Elliott, S. J.; IEEE International Conference on Acoustics, Speech, and Signal Processing
(ICASSP ‘87); Volume 1; 1987, pp. 5.2.1 - 5.2.4; In English; See also 20060001583; Copyright; Avail.: Other Sources
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