Browsing by Author "Reddy, Hari C."

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2-D Digital Filter Architectures without Global Broadcast and Some Symmetry Applications
(2009)
Khoo, I-Hung
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Reddy, Hari C.
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Van, Lan-Da
;
Lin, Chin-Teng
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資訊工程學系
Four new 2-D filter VLSI architectures without global broadcast are presented. The first is a transposed systolic structure which requires fewer delay elements compared to the original systolic structure in [1]. By combining the sub-blocks of the original with the new transposed structure, two additional systolic structures are obtained to realize transfer functions with separable denominators, which require fewer multipliers. These separable denominator structures have important symmetry applications. A structure which possesses diagonal symmetry is then shown which requires even fewer multipliers.
A New VLSI 2-D Diagonal-Symmetry Filter Architecture Design
(2008)
Chen, Pei-Yu
;
Van, Lan-Da
;
Reddy, Hari C.
;
Lin, Chin-Teng
;
資訊工程學系
In this paper, we propose two new two-dimensional (2-D) IIR and FIR filter architectures for 2-D transfer function with diagonal symmetry. The presented type-I structure with diagonal symmetry has the lowest number of multipliers, and zero latency without sacrificing the number of the delay elements. Importantly, the proposed type-II IIR filter possesses high speed, local broadcast, and the same number of multipliers and latency as the type I shows at expense of a slight increment of number of delay elements.
A New VLSI 2-D Fourfold-Rotational-Symmetry Filter Architecture Design
(2009)
Chen, Pei-Yu
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Van, Lan-Da
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Reddy, Hari C.
;
Lin, Chin-Teng
;
資訊工程學系
In this paper, we propose two new two-dimensional (2-D) IIR and FIR filter architectures for 2-D transfer function using fourfold rotational symmetry. The presented type-I structure with fourfold rotational symmetry has the lowest number of multipliers, and zero latency. Importantly, the proposed type-II IIR filter possesses high speed, local broadcast, and the same number of multipliers and latency as the type I shows at expense of a slight increment of number of delay elements.
Area-Efficient 2-D Digital Filter Architectures Possessing Diagonal and Four-Fold Rotational Symmetries
(2013-01-01)
Chen, Pei-Yu
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Van, Lan-Da
;
Reddy, Hari C.
;
Khoo, I-Hung
;
交大名義發表
In this paper, two area-efficient two-dimensional (2-D) IIR filter architectures for 2-D transfer function with diagonal and four-fold rotational symmetries are proposed for image processing. For this purpose, two different intermediate transfer functions are applied and the corresponding two new filter architectures are obtained. Under satisfactory average error performance, we determine that the new filter structure requires less multiplier wordlength than the previously published Type-1 filter structure. With the features of less numerator multiplier wordlength and shorter critical path, the proposed diagonal and four-fold rotational symmetry filter architectures can result in 10.17% and 3.35% area reduction with respect to the published Type-1 IIR filter structures with diagonal and four-fold rotational symmetries in terms of synthesis results.
Delta discrete-time operator based realization procedure for low sensitivity sampled-data and digital ladder filters
(2008)
Khoo, I-Hung
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Reddy, Hari C.
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Moschytz, George S.
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資訊工程學系
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Department of Computer Science
A delta operator based ladder synthesis procedure is presented for the realization of three different types of transfer functions. The procedure overcomes the numerical problem of the conventional z-domain LDI approach when the filter poles are clustered near z=1 and does not require any s-domain polynomial transformation to achieve spectral factorization [4]. Also, the entire operation involves only rational polynomials.
Design of 2-D Digital Filters with Almost Quadrantal Symmetric Magnitude Response without 1-D Separable Denominator Factor Constraint
(2013)
Khoo, I-Hung
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Reddy, Hari C.
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Van, Lan-Da
;
Lin, Chin-Teng
;
資訊工程學系
A design approach is presented for 2-D digital filters possessing approximate quadrantal magnitude symmetry without the constraint of the denominator having only 1-D separable factors. To ensure the BIBO stability of the filter, the planar least square inverse stabilization approach is employed. It is illustrated through design examples that the proposed approach results in filters with sharper transition band and lower error relative to the given filter specifications. Also, for certain cases, it is shown that a lower order non-separable denominator design can achieve the same result as a higher order separable denominator design, thus providing savings in the number of multipliers. Finally, 2-D VLSI realizations without global broadcast are presented for the optimized transfer function with non-separable denominator factors and approximate quadrantal symmetry.
Efficient design of delta operator based 2-D IIR filters using symmetrical decomposition
(2008)
Khoo, I-Hung
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Reddy, Hari C.
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Rajan, P. K.
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資訊工程學系
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Department of Computer Science
A method based on symmetrical decomposition is presented for the design of 2-D IIR filters through optimization. This technique allows a filter with non-symmetric magnitude specification to benefit from the savings in parameters provided by symmetry. The procedure is developed for the delta operator based design to take advantage of its better coefficient sensitivity compared to the z-domain design when the filter is narrowband.
General formulation of shift and delta operator based 2-D VLSI filter structures without global broadcast and incorporation of the symmetry
(2014-10-01)
Khoo, I. -Hung
;
Reddy, Hari C.
;
Van, Lan-Da
;
Lin, Chin-Teng
;
資訊工程學系
Having local data communication (without global broadcast of signals) among the elements is important in very large scale integration (VLSI) designs. Recently, 2-D systolic digital filter architectures were presented which eliminated the global broadcast of the input and output signals. In this paper a generalized formulation is presented that allows the derivation of various new 2-D VLSI filter structures, without global broadcast, using different 1-D filter sub-blocks and different interconnecting frameworks. The 1-D sub-blocks in z-domain are represented by general digital two-pair networks which consist of direct-form or lattice-type FIR filters in one of the frequency variables. Then, by applying the sub-blocks in various frameworks, 2-D structures realizing different transfer functions are easily obtained. As delta discrete-time operator based 1-D and 2-D digital filters (in gamma-domain) were shown to offer better numerical accuracy and lower coefficient sensitivity in narrow-band filter designs when compared to the traditional shift-operator formulation we have covered both the conventional z-domain filters as well as delta discrete-time operator based filters. Structures realizing general 2-D IIR (both z- and gamma-domains) and FIR transfer functions (z-domain only) are presented. As symmetry in the frequency response reduces the complexity of the design, IIR transfer functions with separable denominators, and transfer functions with quadrantal magnitude symmetry are also presented. The separable denominator frameworks are needed for quadrantal symmetry structures to guarantee BIBO stability and thus presented for both the operators. Some limitations of having exact symmetry with separable 1-D denominator factors are also discussed.
Generalized Formulation of 2-D Filter Structures without Global Broadcast for VLSI Implementation
(2010)
Khoo, I-Hung
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Reddy, Hari C.
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Van, Lan-Da
;
Lin, Chin-Teng
;
資訊工程學系
A generalized formulation is developed that allows the derivation of various new 2-D VLSI filter structures, without global broadcast, using different filter sub-blocks and their interconnections (frameworks). With this formulation, lattice-type and direct-form structures realizing general 2-D IIR and FIR transfer functions, IIR transfer functions with separable denominators, and transfer functions with quadrantal magnitude symmetry are easily obtained. The separable denominator and quadrantal symmetry structures have the advantage of reduced number of multipliers.
New 2-D Filter Architectures with Quadrantal Symmetry and Octagonal Symmetry and Their Error Analysis
(2017-01-01)
Chen, Pei-Yu
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Van, Lan-Da
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Reddy, Hari C.
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Khoo, I. H.
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資訊工程學系
In this paper, two new two-dimensional (2-D) IIR and FIR filter architectures possessing quadrantal and octagonal symmetries are proposed. Furthermore, the theoretical error analysis for the proposed filters is also presented. Utilizing the presented error analysis, user can decide the bit width of the filters with satisfactory error tolerance.
New 2-D Quadrantal- and Diagonal-Symmetry Filter Architectures Using Delta Operator
(2017-01-01)
Chen, Pei-Yu
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Van, Lan-Da
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Khoo, I. H.
;
Reddy, Hari C.
;
資訊工程學系
In this paper, we propose two new two-dimensional (2-D) IIR filter architectures with quadrantal and diagonal magnitude symmetry using delta operator. These filter architectures can attain lower coefficient sensitivity in comparison with the traditional shift operator formulation (i.e., the conventional z-domain filters). The IIR filter structures presented not only achieve lower coefficient sensitivity without sacrificing the number of multipliers, but in fact reducing the number of multipliers by 36.36% compared with the previous corresponding quadrantal symmetry filter structures using delta operator with order N=3.
Power-Efficient and Cost-Effective 2-D Symmetry Filter Architectures
(2011-01-01)
Chen, Pei-Yu
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Van, Lan-Da
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Khoo, I-Hung
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Reddy, Hari C.
;
Lin, Chin-Teng
This paper presents two-dimensional (2-D) VLSI digital filter structures possessing various symmetries in the filter magnitude response. For this purpose, four Type-1 and four Type-2 power-efficient and cost-effective 2-D magnitude symmetry filter architectures possessing diagonal, fourfold rotational, quadrantal, and octagonal symmetries with reduced number of multipliers and one power-efficient and cost-effective multimode 2-D symmetry filter are given. By combining the identities of the four Type-1 symmetry filter structures, the proposed multimode 2-D symmetry filter is capable of providing four different operation modes: diagonal symmetry mode (DSM), fourfold rotational symmetry mode (FRSM), quadrantal symmetry mode (QSM), and octagonal symmetry mode (OSM). The proposed diagonal, fourfold rotational, quadrantal, and octagonal symmetry filter structures can attain power savings of 16.77%, 36.30%, 22.90%, and 37.73% with respect to that of the conventional 2-D filter design without symmetry. On the other hand, the proposed DSM, FRSM, QSM, and OSM modes can reduce power consumption by 11.01%, 31.42%, 17.53%, and 35.26% compared with that of the conventional 2-D filter design. The proposed multimode filter can result in a 63.25% area reduction compared with the sum of the areas of the four individual Type-1 symmetry filter structures.
Type-3 2-D Multimode IIR Filter Architecture and the Corresponding Symmetry Filter's Error Analysis
(2017-01-01)
Chen, Pei-Yu
;
Lan-Da Van
;
Reddy, Hari C.
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Khoo, I. H.
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資訊工程學系
In this paper, we propose a low-cost high-speed Type-3 two-dimensional (2-D) multimode symmetry IIR filter architecture including four different operation modes: diagonal symmetry mode (DSM), fourfold rotational symmetry mode (FRSM), quadrantal symmetry mode (QSM), and octagonal symmetry mode (OSM). For multimode purpose, the Type-3 transfer function is applied and the interconnections to achieve corresponding four symmetry filter architectures are proposed. The proposed 2-D IIR filter structure has lower number of adders and shorter critical path than the published Type-1 IIR filter structure without sacrificing multipliers. Furthermore, the theoretical error analysis of 2-D IIR filter architectures with diagonal symmetry and four-fold rotational symmetry is studied.
Type-4 2-D Diagonal and Four-Fold Rotational Symmetry Digital Filter Architectures
(2018-01-01)
Van, Lan-Da
;
Lu, Tsung-Che
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Chen, Pei-Yu
;
Reddy, Hari C.
;
資訊工程學系
In this paper, Type-4 two-dimensional (2-D) separable denominator IIR filter architecture is studied. This structure has a critical path of one multiplication and three additions. Using this Type-4 2-D separable denominator IIR filter architecture, three new 2-D IIR filter structures with diagonal and four-fold rotational symmetries are given. These structures have a critical path of one multiplication and four additions. Further, using a different coefficient constraint, a new Type-3 2-D diagonal symmetry IIR filter architecture with a critical path of one multiplication and two additions is obtained. In all, four different 2-D IIR filter architectures with diagonal and four-fold rotational symmetries are presented.
Unified theory of symmetry for two-dimensional complex polynomials using delta discrete-time operator
(2011-03-01)
Khoo, I. -Hung
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Reddy, Hari C.
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Rajan, P. K.
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資訊學院
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College of Computer Science
The complexity in the design and implementation of 2-D filters can be reduced considerably if the symmetries that might be present in the frequency responses of these filters are utilized. As the delta operator (gamma-domain) formulation of digital filters offers better numerical accuracy and lower coefficient sensitivity in narrow-band filter designs when compared to the traditional shift-operator formulation, it is desirable to have efficient design and implementation techniques in gamma-domain which utilize the various symmetries in the filter specifications. Furthermore, with the delta operator formulation, the discrete-time systems and results converge to their continuous-time counterparts as the sampling periods tend to zero. So a unifying theory can be established for both discrete- and continuous-time systems using the delta operator approach. With these motivations, we comprehensively establish the unifying symmetry theory for delta-operator formulated discrete-time complex-coefficient 2-D polynomials and functions, arising out of the many types of symmetries in their magnitude responses. The derived symmetry results merge with the s-domain results when the sampling periods tend to zero, and are more general than the real-coefficient results presented earlier. An example is provided to illustrate the use of the symmetry constraints in the design of a 2-D IIR filter with complex coefficients. For the narrow-band filter in the example, it can be seen that the gamma-domain transfer function possesses better sensitivity to coefficient rounding than the z-domain counterpart.