Shin'ichi Shiraishi

A cost-effective and high-precision architecture for CORDIC-based adaptive lattice filters

This paper presents a CORDIC-based architecture for adaptive lattice filters. The proposed filter architecture consists of simple components: a CORDIC processor and an adder, so that it can be implemented with a reduced amount of hardware. Moreover, the proposed architecture is useful for ASIC design because it has a regular, modular, and locally-connected structure. In addition, since our architecture is effective even in case of ARMA lattice filters, it can be utilized for many applications in the digital signal processing field.

Convergence Properties of a CORDIC-Based Adaptive ARMA Lattice Filter

This paper presents a theoretical convergence analysis of a CORDIC-based adaptive ARMA lattice filter. In previous literatures, several investigation methods for adaptive lattice filters have been proposed; however, they are available only for AR-type filters. Therefore, we have developed a distinct technique that can reveal the convergence properties of the CORDIC ARMA lattice filter. The derived technique provides a quantitative convergence analysis, which facilitates an efficient hardware design for the filter. Moreover, our analysis technique can be applied to popular multiplier-based filters by slight modifications. Hence, the presented convergence analysis is significant as a leading attempt to investigate ARMA lattice filters.

Convergence analysis of a CORDIC-based gradient adaptive lattice filter

This paper presents a theoretical analysis of a CORDIC-based gradient adaptive lattice filter. First, we provide a convergence model and reveal convergence properties of filter coefficients. Second, we derive a steady-state model based on a Markov chain. By using the steady-state model, the relation between the step size parameter and the variance of the estimation error is clarified. The results of the analysis facilitate an efficient hardware design of the filter.

A highly accurate pipelined architecture for a CORDIC ARMA lattice filter

This paper presents a method to improve implementation accuracy of a recently proposed CORDIC ARMA lattice filter. Since the CORDIC ARMA lattice filter algorithm has a problem in its shift sequence, it cannot implement a lattice filter accurately. Therefore, in this paper we apply the shift sequence proposed by Walther without problem to the CORDIC ARMA lattice filter, and then we realize an accurate lattice filter. In addition, we propose a new pipelined architecture for the CORDIC ARMA lattice filter. The proposed lattice filter architecture consists of CORDIC processors implemented in the pipelined fashion; it can achieve a high data processing throughput rate.

A Steady-State Analysis of a CORDIC-Based Adaptive ARMA Lattice Filter

This paper analyzes steady-state properties of a CORDIC-based adaptive ARMA lattice filter. In our earlier work, convergence properties of the filter in the non-steady state have been clarified; however, its behavior in the steady-state is not discussed. Therefore, we develop a distinct analysis technique based on a Markov chain in order to investigate steady-state properties of the filter. By using the proposed technique, the relation between step size and coefficient estimation error is revealed. We can use the results of the analysis to obtain an efficient design of the filter.

A convergence analysis technique for a CORDIC-based ARMA lattice filter

This paper presents an analysis technique for an adaptive ARMA lattice filter based on the CORDIC algorithm. The proposed technique brings a theoretical convergence analysis, which facilitates an efficient ASIC design of the ARMA lattice filter. Although the proposed technique is dedicated to filters using a special arithmetic unit (CORDIC processor), we can apply it to popular multiplier-based filters through slight modifications. Consequently, we can utilize the proposed technique for many applications in the signal processing.