Chivapreecha, Sorawat
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Preferred name
Chivapreecha, Sorawat
Alternative Name
Chivapreecha, S.
Chivapreecha, Sorwat
Main Affiliation
Email
sorawat.ch@kmitl.ac.th
15 results
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Item type:Publication, Generalized Pascal matrices, inverses, computations and properties using one-to-one rational polynomial s-z transformations(2008-01-01); Dejhan, KobchaiThis paper proposes a one-to-one mapping between the coefficients of continuous-time (s-domain) and discrete-time (z-domain) IIR transfer functions such that the s-domain numerator/denominator coefficients can be uniquely mapped to the z-domain numerator/denominator coefficients. The one-to-one mapping provides a firm basis for proving the inverses of the so-called generalized Pascal matrices from various first-order s-z transformations. We also derive recurrence formulas for recursively determining the inner elements of the generalized Pascal matrices from their boundary ones. Consequently, all the elements of the whole generalized Pascal matrix can be easily generated through utilizing their neighbourhood, which can be exploited for further simplifying the Pascal matrix generations. Finally, we reveal and prove some interesting properties of the generalized Pascal matrices. © 2008 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, An FPGA-based implementation of variable fractional delay filter(2009-10-19); Dejhan, KobchaiA variable fractional delay (VFD) filter is widely used in applications such as symbol timing recovery, arbitrary sampling rate conversion and echo cancellation. This paper presents an implementation of variable fractional delay filter on FPGA. The implementation utilizes an efficient structure so called Taylor structure. The main advantage of this structure is to reduce number of multiplier and adder when compared with Farrow structure or modified Farrow structure. The result of implementation will be reported as throughput and area utilization. ©2009 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Design of multiplierless elliptic narrowband IIR digital filter based on sensitivity analysis(2004-12-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Design and implementation of biquad digital filter(2003-01-01); Dejhan, K.This paper presents a design and implementation of biquad digital filter based on poles-zeros placement on a unit circle of z-plane. The proposed digital filter can be given three frequency-responses as lowpass filter (LPF), highpass filter (HPF) and bandpass filter (BPF) at the same time. In the design process the Matlab program was used, for real world implementation by using TMS320C31 DSP board. The experimental results shown by the dynamic signal analyzer to indicate that the obtained frequency responses give the same results as design specifications. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Adaptive equalization architecture using distributed arithmetic for partial response channels(2006-12-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Bilinear s-z with frequency transformation using pascal matrix operation(2005-12-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, PAPR reduction in OFDM systems using SLM cascade with APPR methods(2008-10-06); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Unified Pascal matrix for first-order s-z domain transformations(2009-06-16); Dejhan, KobchaiThe so-called generalized Pascal matrix is used for transforming a continuous-time (CT) linear system (filter) into a discrete-time (DT) one. This paper derives an explicit expression for a new generalized Pascal matrix called unified Pascal matrixfrom a unified first-order s-z transformation model and rigorously proves the inverses for various first-order s-z transformations. After deriving a recurrence formula for recursively generating the inner elements of the unified Pascal matrix from its boundary elements, we also show that the recurrence formula leads to computationally unstable solutions for high-order systems due to the so-called catastrophic cancellation in numerical computation, but the unstable problem can be solved through partitioning the whole unified Pascal matrix into several small matrices (submatrices) and then using the recurrence formula to compute the submatrices individually from their boundary elements. This operation almost retains the same computational complexity while guarantees numerically stable solutions. Moreover, an interesting property of the unified Pascal matrix is proved. © 2009 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Even order biquad digital filter design using pascal matrix(2008-12-01); Dejhan, KobchaiThis paper presents new design method and structure of IIR digital filter. The new design method is based on bilinear s-z transformation and Pascal matrix theorem. These theories are used to transform the normalized analog transfer functions to digital transfer functions. The structure of IIR digital filter is modified for even order biquad digital filter which can give frequency response simultaneously as low-pass, high-pass, band-pass and band-stop filtering. The new structure use delay units the same as single frequency response IIR digital filters that has same order.I © 2008 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A CMOS median filter circuit design(2006-12-01); Dejhan, KobchaiThis paper proposes a median filter circuit design, which the operations are in current mode and based on CMOS technology. Its structure consists of three main parts, the first part is current average circuit, second part is current absolute value circuit, and third part is current minimum circuit. The results of this circuit can be shown using the PSpice simulation program to demonstrate the performances of this circuit. © 2006 IEEE.