• ETRI Journal
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• v.34 no.3
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• pp.379-387
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• 2012

In this paper, an error compensation technique for a dead reckoning (DR) system using a magnetic compass module is proposed. The magnetic compass-based azimuth may include a bias that varies with location due to the surrounding magnetic sources. In this paper, the DR system is integrated with a Global Positioning System (GPS) receiver using a finite impulse response (FIR) filter to reduce errors. This filter can estimate the varying bias more effectively than the conventional Kalman filter, which has an infinite impulse response structure. Moreover, the conventional receding horizon Kalman FIR (RHKF) filter is modified for application in nonlinear systems and to compensate the drawbacks of the RHKF filter. The modified RHKF filter is a novel RHKF filter scheme for nonlinear dynamics. The inverse covariance form of the linearized Kalman filter is combined with a receding horizon FIR strategy. This filter is then combined with an extended Kalman filter to enhance the convergence characteristics of the FIR filter. Also, the receding interval is extended to reduce the computational burden. The performance of the proposed DR/GPS integrated system using the modified RHKF filter is evaluated through simulation.

• Journal of Biomedical Engineering Research
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• v.28 no.3
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• pp.423-428
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• 2007

Programmable FIR filters are used in various signal processing tasks in medical ultrasound imaging, which are one of the major factors increasing hardware complexity. A widely used method to reduce the hardware complexity of a programmable FIR filter is to encode the filter coefficients in the canonic signed digit (CSD) format to minimize the number of nonzero digits (NZD) so that the multipliers for each filter coefficients can be replaced with fixed shifters and programmable multiplexers (PM). In this paper, a new structure for programmable FIR filters with a improved frequency response and a reduced hardware complexity compared to the conventional shift-and-add architecture using PM is proposed for implementing a very small portable ultrasound scanner. The CSD codes are optimized such that there exists at least one common nonzero digit between neighboring coefficients. Such common digits are then implemented with the same shifters. For comparison, synthesisable VHDL models for programmable FIR filters are developed based on the proposed and the conventional architectures. When these filters have the same hardware complexity, pass-band ana stop-band ripples of the proposed filter are lower than those of the conventional filter by about $0.01{\sim}0.19dB$ and by about $5{\sim}10dB$, respectively. For the same filter performance, the hardware complexity of the proposed architecture is reduced by more than 20% compare to the conventional SaA architecture.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.758-761
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• 2007

Digital signal processing technique is applied in wide fields such as speech processing, image processing and spectrum analysis. Therefore, in order to do frequency selective operation digital filter is used in stead of analog filter and sharp filter characteristics can be implemented. Since finite impulse response (FIR) digital filter as nonrecursive type represents linear phase response characteristics and is always stable and is used in fields regarding wave information importantly such as data transmission. And due to frequency characteristics, in order to remove the Gibbs phenomenon generating around a discontinuous point, filter is designed through window function method. Therefore, in this paper to improve performance of FIR digital filter, a modified window function was applied. And the proposed method was compared with conventional methods using peak side-lobe and transition properties in simulations.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.3
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• pp.204-209
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• 2004

A partial matched filter (PMF) for semi-coherent correlation code acquisition of the DSSS-CPFSK signal is proposed. It is a calculation-reduced structure of the hard-limited signal based FIR filter, yet its code acquisition time is equal to that of the hard-limited signal based FIR filter. The PMF eliminates duplicate calculations by utilizing the characteristic that the hard-limited DSSS-CPFSK signal has same value in several consecutive samples. For example, the PMF can achieve about 95% reduction in gate size, as compared to the hard-limited signal based FIR filter, when the modulation index of the DSSS-CPFSK signal is equal to 1.5 and the sample rate is equal to 40 sample/chip.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.352-355
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• 1995

In this paper, estimation error bounds of the optimal FIR (Finite Impulse Response) filter, which is proposed by Kwon et al.[1, 2], are presented in discrete-time systems with the model uncertainty. Performance bounds are here represented by the upper bounds on the difference of the estimation error covariances between the nominal and real values in case of the systems with the noise or model parameter uncertainty. The estimation error bounds of the discrete-time optimal FIR filter is compared with those of the Kalman filter via a numerical example applied to the simulation problem by Toda and Patel[3]. Simulation results show that the former has robuster performance than the latter.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.759-762
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• 1996

In previous work Kwon and Yoo [5] have shown that the FIR tracking algorithm using the input estimation technique. However, it has not solved the problem of systems with parameter uncertainties. Therefore, in this paper we propose a new robust $H_{\infty}$ FIR tracking filter to solve the target tracking problems under systems with parameter uncertainties. Also, we use here the input estimation approach to account for the possibility of maneuver. Simulation results show that the robust $H_{\infty}$ FIR tracking filter proposed here still has good tracking performance for a maneuvering target tracking problem even under all system parameter uncertainties.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.183-186
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• 2002

In this paper, we present an area-efficient programmable FIR digital filter using canonic signed-digit(CSD) coefficients, in which the number of effective nonzero bits of each filter coefficient is reduced by sharing the shift and add logics for common nonzero bits between adjacent coefficients. Also, unused shift and add logics for a low- magnitude coefficient are reassigned to an appropriate high - amplitude coefficient. In consequence, the proposed architecture reduces the hardware area of a programmable FIR filter by about 24% and improves performance about 6-7dB compared to other multiplierless FIR filters with powers-of-two coefficients.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.45-48
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• 2005

In this paper, we propose a new fast running FIR filter structure that improves the convergence speed of adaptive signal processing and reduces the computational complexity. The proposed filter is applied to wavelet based adaptive algorithm. Actually we compared the performance of the proposed algorithm with other algorithm using computer simulation of adaptive noise canceler based on synthesis speech. As the result, We know the proposed algorithm is prefer than the existent algorithm.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.827-830
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• 2003

This paper proposes an area-efficient FIR filter architecture for sampling rate conversion of hi-fi audio data. Sampling rate conversion(SRC) block converts audio data sampled at 96KHz down to 48KHz sampled data and vice versa. 63-tap FIR filter coefficients have been synthesized that gives 100dB stop band attenuation and 5.2KHz transition bandwidth. Time-shared filter architecture requires only one multiplier and accumulator for 63-tap filter operation. This results in huge hardware saving of up to 10~19 times smaller compared with traditional FIR structure.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.447-452
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• 1992

The optimal FIR filter and smoother for estimating the state of 2-D state-space model are derived. Using the 2-D state covariance propagation rule suggested in this paper, the efficient algorithm to find the impulse response of the optimal FIR filter and smoother can be found. The filter and smoother can be applied to the image restoration problems and some examples of the application will be given.