This paper presents search methods to optimize word-length for digital systems. Finding the word-length is tedious work when the variables for optimization are numerous. We have proposed sequential and preplanned searches to find out optimum wordlength, and compared them in terms of the trials. A comparison for a given optimized point is evaluated. We apply them to word-length optimization for ...

The existing q-Markov COVER realization theory does not take into account the problems of arithmetic errors due to both the quantization of states and coefficients of the reduced order model. All q-Markov COVERs allow some freedom in the choice of parameters. In this paper we exploit this freedom in the existing theory to optimize the models with respect to thes,_ finite wordlength effects. *De...

This brief paper compares the performances achieved with the conventional digital redesign techniques with those obtained with the modern global digital redesign methods such as the plant input mapping methods and the optimal digital redesign approach. The study based on a benchmark control system reveals that the reduced-order plant input mapping method, and not the optimal approach, offers wh...

Abtrac t This paper presents an FIR fllter system capable of implementing virtually any practical lowpass and highpass filter with as little as 60-60 multiplications per sample. The method b based on multirate techniques and complementary Alters. We first give a brief presentation of the principle and the necessary building blocks. Then, practical design methods for optimitation are presented t...

A technique for reducing the hardware complexity of constant coefficient finite impulse response (FIR) digital filters, without increasing the number of adder steps in the multiplier block adders, is presented. The filter coefficients are adjusted so that the number of full adders in the hardware implementation of any coefficient is independent of the coefficient wordlength and the number of sh...

This work inrmduces a technique for updaring messages rhar originare ar rke consrrainr nodes of bi-partite graphs in Low-Density Parity-Check codes. The rechnique computes only WO ourgoing magnitudes ar each consrrainr node and exhibirs no measurable performance loss as compared ro exact belief propagation which compures a unique magnirude for each departing edge fmm a given consrrainr node. Th...

Among various direct-form delta operator realized filter structures, the delta transposed direct-form II ( DFIIt) has been shown to produce the lowest roundoff noise gain in finite wordlength implementations. Recent analyses focus on the optimization of the free parameter of the delta operator, with scaling of the structure to prevent arithmetic overflow. This paper proposes a modified DFIIt se...

Due to its simple and real arithmetic structure Number Theoretic Transform is attractive for computation of convolution. However, there exists a stringent relation between the choice of modulus M and convolution length. Choice of modulus as K.2+1, a prime, leads to relaxation of this constraint and wide choices of wordlength, with each of these associated with many choices of convolution length...

This paper proposes a design method of separable denominator 2-D variable digital filters with high frequency tuning accuracy. In the proposed method, a parallel allpass structure with complex coefficients is used as a prototype structure of the 2-D variable digital filters. The proposed 2-D variable digital filters are composed of first-order complex allpass sections. To improve the frequency ...

Discrete-valued chaotic sequences, when used as long-period spreading codes, are expected to greatly reduce the vulnerability of spread spectrum systems to the devastating jamming based on duplication of the sequence generation mechanism. In this paper, weakness of digital chaotic sequences is reported. We demonstrate that it is possible to reconstruct a long-period discrete-valued sequence gen...