• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.973-976
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• 2009

Digital signal processing technique use to variety fields including communication. For these signal processing, FIR digital filter is representative. And for FIR digital filter designing, the window function is used to reduce the Gibbs phenomenon which occurs in the coefficient cutting process of the ideal filter. Therefore, in this paper to improve performance of digital filter, a high-order window function was applied. In this simulation, we compared a peak side-lobe and a transient characteristics with the existing window function.

• Journal of Broadcast Engineering
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• v.16 no.1
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• pp.174-177
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• 2011

In this paper, we investigate a method for designing FIR filters with CSD coefficients. Firstly, the H/W complexity of a CSD FIR filter is estimated in terms of number of gates. Using the estimated complexity, an optimal filter that can meet the required performance with minimal H/W complexity can be designed. Next, based on the MILP problem solver called BonsaiG, we present a filter design program. From the two design examples, it is demonstrated that an optimal filter can be obtained by comparing the complexity of the candidate filters in terms of the gate counts, whose differences are estimated to be about 400-600 gates.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3A
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• pp.328-336
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• 2006

A novel pre-equalization method for terrestrial DTV transmitters is presented. A pre-equalizer has been used in transmitters to correct group delay and amplitude distortions caused by a channel filter. In the proposed pre-equalizer, an equation-error adaptive IIR filtering scheme is adopted unlike the conventional pre-equalization using FIR filtering schemes. The pole-zero modelling property of IIR filters improves the signal-to-noise ratio and may deal with diverse linear distortions existing in DTV transmitters as well as the channel filter distortion. Simulation results show that the proposed IIR pre-equalizer performs better than the FIR pre-equalizer in terms of the residual mean-square error.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.6
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• pp.1025-1031
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• 2006

In this paper, a deconvolution filtering method for all-pass systems based on FIR approximation is proposed. The proposed method enables us to obtain a causal stable deconvolution filter by FIR approximating a non-causal stable deconvolution filter to a causal stable one. As we can see in this paper, the impulse response of the deconvolution filter for all-pass system is simply the mirror image of the impulse response for all-pass system itself. Due to this symmetric property between all-pass system itself and its deconvolution Inter, this method can be applied to all-pass systems without special limitation of the system's order. In order to verify the performance of the proposed method. computer simulation results for 1st-, 2nd- and 400th-order all-pass systems are included.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.1
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• pp.62-74
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• 2008

In this paper, we would like to propose the design of symmetric digital filter core in order to use in the radio astronomy. The function of FIR filter core would be designed by VHDL code required at the Data Acquisition System (DAS) of Korean VLBI Network (KVN) based on the FPGA chip of Vertex-4 SX55 model of Xilinx company. The designed digital filter has the symmetric structure to increase the effectiveness of system by sharing the digital filter coefficient. The SFFU(Symmetric FIR Filter Unit) use the parallel processing method to perform the data processing efficiently by using the constrained system clock. In this paper, therefore, for the effective design of SFFU, the Unified Synthesis software ISE Foundation and Core Generator which has excellent GUI environment were used to overall IP core synthesis and experiments. Through the synthesis results of digital filter core, we verified the resource usage is less than 40% such as Slice LUT and achieved the maximum operation frequency is more than 260MHz. We also confirmed the SFFU would be well operated without error according to the SFFU simulation result using the Modelsim 6.1a of Mentor Graphics Company. To verify the function of SFFU, we carried out the additional simulation experiments using the pseudo signal to the Matlab software. From the comparison experimental results of simulation and the designed digital FIR filter, we confirmed the FIR filter was well performed with filter's basic function. So we verified the effectiveness of the designed FIR digital filter with symmetric structure using FPGA and VHDL.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06e
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• pp.35-38
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• 1998

입체음향 시스템의 방향감 제어에서 필수적인 머리전달함수(Head-Related Transfer Function)는 일반적으로 FIR 또는 IIR 필터로 구현되며, IIR 필터의 경우 FIR 보다 비교적 저차 모델링이 가능한 장점을 갖는다. 본 논문에서는 Balanced Model Reduction(BMR) 방법을 이용하여 비교적 높은 차수를 가지는 FIR 형태의 HRTF 필터를 IIR 필터로 설계하고, 입체음향 시스템의 실시간 구현시 필수적인 계산의 효율을 높이는 방법을 제시한다. 또한 IIR 필터로 근사화된 HRTF 필터의 주파수 패턴을 분석하여, 음상정위에 큰 영향을 미치는 주파수 대역을 좀 더 나은 해상도를 갖도록 설계하여 저차 모델 설계시 발생하는 오차가 음상정위에 미치는 영향을 최소화 하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.10
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• pp.35-40
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• 2006

In this paper, a current-mode analog variable finite-impulse-response (FIR) filter with variable tap coefficient circuits is proposed for frequency selective wireless personal area network(WPAN) system or terminals. From the circuit simulation the operation of the 7-tap FIR filter is confirmed. The 0.0625-step tap coefficient circuit is designed and fabricated with $0.8[{\mu}m]$ CMOS technology. The proposed FIR filter has a variable length of taps and variable coefficients, so it has a potential for being used to frequency selective WPAN system or frequency selective wireless communication terminals.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.5
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• pp.442-452
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• 1989

This Paper describes the impleentation of two's complement bit-serial FIR filter with systolic architectur. The filter coefficients are represented as sign and magnitude form and the input data is represented as two's complement form. We use systolic array to obtain high operation speed so this FIR filter sucessfully operates in real-time environment.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.565-568
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• 2001

이 논문에서는 미디언 필터의 선형 조합을 통해 임의의 주파수 특성을 갖는 필터 구조와 그 설계 방법을 제안한다. Linear-phase FIR 저대역통과 필터의 홀수번째 필터 계수의 부호를 바꾸면 FIR 고대역 통과 필터를 얻을 수 있는데, 이것은 필터 계수의 부호가 모두 양수인 두 개의 부분 필터의 차와 같은 모양을 가진다. 이 과정을 일반화하여 비선형 필터에 적용하면 LCWM(linear combination of median filter)필터는 가중 미디언 부필터(sub-filter)의 선형 조합으로 구성된다. 이는 선형 대수학에서 어떤 공간상의 임의의 벡터가 그 공간의 기저 (basls) 벡터들의 선형 조합으로 표현된다는 사실과 유사하다. 따라서 부필터의 필터 계수를 기저 벡터로이용하여 얻어지는 기저 행렬과 필터의 주파수 특성을 조절하는 계수 벡터를 구함으로써 LCWM 필터를 설계할 수 있다. 제안된 필터 설계 방법을 이용하면 특정 주파수 특성을 가지는 FIR 필터와 유사한 특성을 갖는 비선형 필터 구조를 만들 수 있다. LCWM 필터는 고대역 통과, 저대역 통과, BP(band-pass), BS(band-stop)의 임의의 주파수 특성을 가지는 필터로 설계될 수 있음이 실험을 통해 확인되었다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.4C
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• pp.377-385
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• 2010

In this paper, a general and explicit technique is presented for determining the filter coefficients of maximally flat (MAXFLAT) FIR filter with the magnitude response exactly passing through a prescribed cutoff point. This technique is based on a general formula (i.e. impulse response) with an arbitrary cutoff point and permits direct computation of the coefficients of this filter type with a specified cutoff point. The technique provides an explicit method for choosing the order of flatness of the filter with the specified cutoff point. Also, in the paper, it is shown to give a computationally efficient and accurate solution to the design of the filters with the desired cutoff point.