• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.77-78
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• 2006

This paper presents a signal quality estimation technique for QAM modulation systems. By making a LUT(Look-up table) putting the number of N enough, we can derive estimated SNR from LUT even though N is small. That is so called MOTM algorithm. In 16-QAM, the distance $d_a$, between adjacent symbols is always invariable, so absolute value of R(the amplitude of signal) minus $d_a$ has a always same signal distribution value. This value does not form a Gaussian shape but, by making a little bit correction, we can make this symmetrical. So, from the received symbol value, by using LUT we can easily derive the estimated SNR. By considering this, we introduce a signal quality estimation technique for QAM schemes. This proposed method can be applicable to high order modulation schemes and wide range of signal to noise ratio.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.4
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• pp.23-29
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• 2015

In this paper, we introduce a underwater ranging algorithm with Look-up Table (LUT) by modifying the existing method which is using the changes of angles of accoustic rays with SSP (Sound Speed Profile). We compare the horizontal distance errors and the calculation times. Our new algorithm exploits Time of Arriva l(ToA) - horizontal distance table based on SSP. This algorithm offers faster calculation speed than the previous one with the slight increase of the distance estimation error.

• Journal of Power Electronics
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• v.19 no.6
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• pp.1429-1439
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• 2019

Buck-Boost LLC (BBLLC) converters based on a PWM + phase control strategy are good candidates for high efficiency, high power density and wide input range applications. Nevertheless, they suffer from large computational complexity when it comes to calculating the optimal phase for ZVS of all the switches. In this paper, a method is proposed for a microcontroller unit (MCU) to calculate the optimal phase quickly and accurately. Firstly, a 2-D lookup table of the phase is established with an index of the input voltage and output current. Then, a bilinear interpolation method is applied to improve the accuracy. Meanwhile, simplification of the phase equation is presented to reduce the computational complexity. When compared with conventional curve-fitting and LUT methods, the proposed method makes the best tradeoff among the accuracy of the optimal phase, the computation time and the memory consumption of the MCU. Finally, A 350V-420V input, 24V/30A output experimental prototype is built to verify the proposed method. The efficiency can be improved by 1% when compared with the LUT method, and the computation time can be reduced by 13.5% when compared with the curve-fitting method.

• Journal of IKEEE
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• v.23 no.2
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• pp.461-468
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• 2019

A continuous-time Delta-Sigma ADC has various benefits; it does not require an explicit anti-aliasing filter, and it is able to handle wider-band signals with less power consumption in comparison with a discrete-time Delta-Sigma ADC. However, it inherently needs to sample the signal with a high-speed clock, necessitating a complex decimation filter that operates at high speed in order to convert the modulator output to a low-rate high-resolution digital signals without causing aliasing. This paper proposes a continuous-time Delta-Sigma ADC architecture that employs pulse-width modulation and shows that the proposed architecture lends itself to a simpler implementation of the decimation filter using a lookup table.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.3 s.309
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• pp.25-33
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• 2006

This paper proposed device-independent color matching algorithm based on the 3D RGB lookup table (LUT) between mobile camera and mobile LCD (Liquid Crystal Display) to improve the color-fidelity. Proposed algorithm is composed of thee steps, which is device characterization, gamut mapping, 3D RGB-LUT design. First, the characterization of mobile LCD is executed using the sigmoidal function, different from conventional method such as GOG (Gain Offset Gamma) and S-curve modeling, based on the observation of electro-optical transfer function of mobile LCD. Next, mobile camera characterization is conducted by fitting the digital value of GretagColor chart captured under the daylight environment (D65) and tristimulus values (CIELAB) using the polynomial regression. However, the CIELAB values estimated by polynomial regression exceed the maximum boundary of the CIELAB color space. Therefore, these values are corrected by linear compression of the lightness and chroma. Finally, gamut mapping is used to overcome the gamut difference between mobile camera and moible LCD. To implement the real-time processing, 3D RGB-LUT is designed based on the 3D RGB-LUT and its performance is evaluated and compared with conventional method.

• Journal of Broadcast Engineering
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• v.10 no.3
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• pp.413-421
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• 2005

As the population of HDTV is growing, among many useful features of modern set top boxes (STBs) or digital video recorders (DVRs), video browsing, visual bookmark, and picture-in-picture capabilities are very frequently required. These features typically employ reduced-size versions of video frames, or thumbnail images. Most thumbnail generation approaches generate DC images directly from a compressed video stream. A discrete cosine transform (DCT) coefficient for which the frequency is zero in both dimensions in a compressed block is called a DC coefficient and is simply used to construct a DC image. If a block has been encoded with field DCT, a few AC coefficients are needed to generate the DC image in addition to a DC coefficient. However, the bit length of a codeword coded with variable length coding (VLC) cannot be determined until the previous VLC codeword has been decoded, thus it is required that all codewords should be fully decoded regardless of their necessary for DC image generation. In this paper, we propose a method especially for fast DC image generation from an I-frame using multiple-symbol lookup table (mLUT). The experimental results show that the method using the mLUT improves the performance greatly by reducing LUT count by 50$\%$.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1992.06a
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• pp.447-451
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• 1992

• Proceedings of the Korean Printing Society Conference
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• 2002.05a
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• pp.3-9
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• 2002

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.9
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• pp.1851-1857
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• 2009

In this paper, reuse module generation algorithm consider the power consumption for FPGA technology mapping is proposed. To proposed algorithm is RT library generating algorithm consider power consumption for reuse module using FPGA technology mapping. In the first, selected FPGA for power consumption calculation. Technology mapping process have minimum total power consumption consider LUT's constraint in selected FPGA. A circuit into device by selected proper modules of allocation result for power consumption constraint using data.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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• pp.391-397
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• 2018

This paper proposes a interpolation error compensation method for PMSM torque control. In PMSM torque control, two dimensions look-up table(2D-LUT) is used for current reference generation due to its stable and robust torque control performance. However, the stored data in 2D-LUT is discreet, it is impossible to store all over the operation range. To reduce the reference generation error in this region, the 2D-Interpolation method is conventionally used, however, this method still remains the error affected by the number of stored data. Besides, in the case stored by fixed unit, this error is increased in field weakening region because of the small number of stored data. In this paper, analyzing the cause of this interpolation error, and compensating the method to reduce this error. Proposed method is verified by the simulation and experiment.